GROKID ​ ​SYRUP

Mechanism of action

Cyanocobalamin serves as a cofactor for methionine synthase and L-methylmalonyl-CoA mutase enzymes. Methionine synthase is essential for the synthesis of purines and pyrimidines that form DNA. L-methylmalonyl-CoA mutase is involved in the degradation of propionate, crucial for fat and protein metabolism. The lack of vitamin B12 results in the accumulation of methylmalonyl CoA, contributing to neurological manifestations. Additionally, it is vital for the synthesis of methionine from homocysteine, and its deficiency can lead to functional folate deficiency, which impacts red blood cell formation.

Pharmacodynamics

Cyanocobalamin corrects vitamin B12 deficiency and alleviates symptoms and laboratory abnormalities associated with pernicious anemia, such as megaloblastic indices, gastrointestinal lesions, and neurological damage. It is essential for growth, cell reproduction, hematopoiesis, nucleoprotein, and myelin synthesis. The drug significantly impacts fat and carbohydrate metabolism, as well as protein synthesis. Rapidly dividing cells, such as those in the bone marrow, have a high demand for vitamin B12. Parenteral administration of cyanocobalamin can quickly reverse the anemia and gastrointestinal symptoms of vitamin B12 deficiency, while also preventing the progression of related neurological damage.

Pharmacokinetics

Cyanocobalamin is absorbed in the intestine, primarily in the ileum, via specific transport mechanisms that may be impaired in individuals with intrinsic factor deficiency (as seen in pernicious anemia). Once absorbed, it is widely distributed in body tissues, with significant concentrations found in the liver, kidneys, and heart. The vitamin is stored in the liver, where it can be released into circulation as needed. Cyanocobalamin undergoes conversion to its active forms, methylcobalamin and adenosylcobalamin, which are utilized in various metabolic processes. The elimination half-life is variable, but it is generally excreted via urine as metabolites

Adverse effects

• Abdominal distension
• Decreased appetite
• Flatulence
• Nausea

Interactions

• Folic acid may interact with cyanocobalamin, especially in cases of megaloblastic anemia caused by folate deficiency.

Precautions

• Should not be given alone for pernicious anemia.
• Use caution in patients with Leber's disease, as it may worsen optic atrophy.

Pregnancy

Cyanocobalamin is essential during pregnancy as it helps prevent neural tube defects. It is advised that females of childbearing potential take 5 mg of folic acid daily before conception and throughout pregnancy.

Breast-feeding

Cyanocobalamin is generally considered safe during breastfeeding, but it is advised to monitor the infant for any adverse effects.

Storage

Store in a cool, dry place, away from direct sunlight. Protect from moisture.

Formulations

• Tablet: 1000 micrograms
• Tablet: 500 micrograms
• Tablet: 100 micrograms
• Oral solution: 50 micrograms per ml
• Solution for injection: 1000 micrograms per ml

Indications

• Iron deficiency anemia
• Prophylaxis of iron deficiency in at-risk populations
• Epithelial tissue changes such as atrophic glossitis and koilonychia

Dosage

Children: For children aged 1 month to 11 years: 0.25 mL per kilogram twice daily, with the total daily dose possibly given in 3 divided doses, not exceeding 20 mL per day. For children aged 12-17 years: 10 mL once daily.

Adults: The dose is calculated according to body weight and the iron deficit, specifying both the iron salt and formulation. For specific dosing, consult product literature.

Mechanism of action

Iron is necessary for the production of hemoglobin. Iron deficiency can lead to decreased production of hemoglobin and a microcytic, hypochromic anemia. Ferrous fumarate releases iron in the gastrointestinal tract, facilitating its absorption and subsequent incorporation into hemoglobin, thus alleviating anemia.

Pharmacodynamics

The major activity of supplemental iron, including ferrous fumarate, is in the prevention and treatment of iron deficiency anemia. Iron also has putative immune-enhancing, anticarcinogenic, and cognition-enhancing activities, supporting overall health and functionality.

Pharmacokinetics

Ferrous fumarate is absorbed in the gastrointestinal tract, with absorption being optimal in an acidic environment. The bioavailability can be influenced by dietary factors, such as the presence of certain foods or medications that may inhibit iron absorption. Once absorbed, iron is transported in the blood bound to transferrin and is stored in tissues as ferritin and hemosiderin. The elimination half-life of iron is variable and depends on the individual's iron status and the amount of iron stored.

Contra-indications

• Iron overload syndromes
• Repeated blood transfusions
• Porphyria cutanea tarda

Adverse effects

• Asthenia
• Drowsiness
• Urine discoloration
• Cold sweat
• Confusion
• Decreased level of consciousness
• Thrombophlebitis
• Headache
• Joint stiffness
• Pain in extremities
• Skin reactions
• Small intestinal bacterial overgrowth
• Thirst
• Nausea
• Constipation
• Diarrhea
• Decreased appetite

Interactions

• Iron absorption may be affected by antacids and certain medications that alter gastric pH.

Precautions

• Monitor iron status to avoid iron overload.
• Caution in patients with intestinal strictures or diverticular disease.
• Care in elderly patients and those on high doses.

Pregnancy

Iron is generally considered safe during pregnancy, but supplementation should be monitored to avoid overload.

Breast-feeding

Iron supplementation may be necessary for exclusively breast-fed infants if maternal iron stores are low.

Storage

Store in a cool, dry place, away from direct sunlight. Keep out of reach of children.

Formulations

• Solution for injection (Iron as Iron sucrose 20 mg per 1 ml)
• Capsules containing iron formulations

Indications

• Vitamin A deficiency
• Isoniazid-induced neuropathy (prophylaxis)
• Isoniazid-induced neuropathy (treatment)
• Idiopathic sideroblastic anaemia
• Wilson's disease (treatment and prevention of penicillamine-induced neuropathy)
• Premenstrual syndrome

Dosage

Children: For children aged 1 to 11 months, 5000 units daily, to be taken with or after food. Higher doses may be used initially for treatment of severe

Adults: 20–50 mg by mouth 1–3 times a day for Vitamin A deficiency. For Isoniazid-induced neuropathy, the dosage varies: 50 mg 3 times a day for treatment, and 20 mg daily for prophylaxis.

Mechanism of action

Vitamin A acts primarily through its active metabolite, retinoic acid, which regulates gene expression by activating specific nuclear receptors known as retinoic acid receptors (RARs) and retinoid X receptors (RXRs). This pathway influences cellular growth, differentiation, and apoptosis, and is critical in the development of the visual system and immune responses.

Pharmacodynamics

Vitamin A exhibits its pharmacological effects by maintaining normal vision, supporting immune function, and promoting skin health. It is essential for the synthesis of rhodopsin, a pigment in the retina that is necessary for low-light vision. The vitamin also plays a role in the regulation of epithelial cell turnover and differentiation, influencing the health of skin and mucosal tissues.

Pharmacokinetics

Vitamin A is absorbed in the intestines, primarily in the presence of dietary fat. It is stored in the liver and released into the bloodstream bound to retinol-binding protein. The elimination half-life varies and is influenced by the amount of vitamin A stored in the body. Excessive intake can lead to toxicity, as Vitamin A is retained in the body rather than excreted.

Contra-indications

• Hyperkalaemia
• Severe liver damage
• Renal impairment (eGFR less than 45 mL/minute/1.73 m2)

Adverse effects

• Rough skin
• Dry hair
• Enlarged liver
• Increased erythrocyte sedimentation rate
• Increased serum calcium
• Increased serum alkaline phosphatase concentration

Interactions

• Isoniazid (may induce neuropathy)
• Other medications that affect liver function

Precautions

• Monitor liver function tests monthly during treatment
• Discontinue immediately if liver function tests are elevated
• Avoid high doses in pregnant women to prevent birth defects
• Monitor closely when initiating treatment with very high doses

Pregnancy

Women who are pregnant or may become pregnant are advised against taking vitamin A supplements, including tablets and fish liver oil drops, except on the advice of a doctor or antenatal clinic.

Breast-feeding

There is a theoretical risk of toxicity in infants if mothers take large doses of vitamin A.

Storage

Store in a cool, dry place, away from direct sunlight.

Formulations

• Vitamin A 150,000 units/ml drops (Arovit)
• Vitamin A (as Vitamin A palmitate) 50,000 units/ml solution for injection (Aquasol A)

Indications

• Iron-deficiency anemia (therapeutic)
• Iron-deficiency anemia (prophylactic)

Dosage

Children: Child 1 month–11 years: 0.25 mL/kilogram twice daily, the total daily dose may alternatively be given in 3 divided doses; maximum 20 mL per day. Child 12–17 years: 10 mL once daily.

Adults: 10 mL 1–2 times a day, equivalent to 600 mg daily.

Mechanism of action

Iron is necessary for the production of hemoglobin. Iron-deficiency can lead to decreased production of hemoglobin and a microcytic, hypochromic anemia. By supplying iron, ferrous gluconate aids in restoring hemoglobin levels and correcting anemia.

Pharmacodynamics

The major activity of supplemental iron, including ferrous gluconate, is in the prevention and treatment of iron deficiency anemia. Iron has additional roles that may enhance immune function, exhibit anticarcinogenic properties, and improve cognitive functions.

Pharmacokinetics

Ferrous gluconate is absorbed in the gastrointestinal tract, with absorption being enhanced in acidic environments. The iron is then transported in the bloodstream bound to transferrin, and utilized by the body for hemoglobin synthesis and other metabolic functions. Excess iron is stored in the liver, spleen, and bone marrow. The pharmacokinetics can vary based on individual patient factors such as age, sex, and overall health.

Adverse effects

• Gastrointestinal disturbances
• Constipation
• Diarrhea
• Nausea
• Vomiting
• Staining of teeth (with liquid formulations)
• Haemosiderosis (with excessive use)

Interactions

• Antacids may reduce iron absorption
• Tetracyclines may form insoluble complexes with iron
• Food containing calcium may decrease iron absorption

Precautions

• Caution in patients with peptic ulcer disease
• Caution in patients with intestinal strictures and diverticular disease
• Monitor for signs of overdose, particularly in children

Pregnancy

Iron supplementation is generally recommended during pregnancy to prevent iron-deficiency anemia, but dosage should be guided by clinical assessment.

Breast-feeding

Iron supplementation can be used during breastfeeding, with consideration for the iron needs of the infant.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Ferrous gluconate 300 mg tablets
• Ferrous gluconate oral solution (140 mg/5 mL)

Indications

• Iron-deficiency anemia (therapeutic)
• Iron-deficiency anemia (prophylactic)

Dosage

Children: For children aged 1 month to 11 years: 0.25 mL/kilogram twice daily. For children aged 12 to 17 years: 10 mL once daily.

Adults: 280 mg twice daily.

Mechanism of action

Ferrous sulfate acts as a source of iron, which is essential for the synthesis of hemoglobin, the protein in red blood cells that carries oxygen. Iron is absorbed in the intestines, where it is converted into a form that can be incorporated into hemoglobin. The mechanism involves transport proteins that facilitate iron uptake and incorporation into the heme group of hemoglobin.

Pharmacodynamics

The pharmacodynamic effect of ferrous sulfate is the increase in hemoglobin levels and improvement in symptoms of anemia, such as fatigue and weakness. Iron supplementation leads to increased erythropoiesis (red blood cell production) in the bone marrow, effectively correcting the deficit in iron stores and enhancing oxygen-carrying capacity.

Pharmacokinetics

Ferrous sulfate is absorbed in the gastrointestinal tract, particularly in the duodenum and proximal jejunum. The bioavailability of iron from ferrous sulfate can be affected by dietary factors, with enhanced absorption in acidic environments. Peak plasma concentrations typically occur within 2 to 6 hours post-administration. Iron is primarily stored in the liver and bone marrow, and any excess iron is excreted through feces, urine, and sweat.

Contra-indications

• Hypersensitivity to ferrous sulfate or any of its excipients
• Hemochromatosis
• Hemosiderosis
• Thalassemia
• Other anemias not due to iron deficiency

Adverse effects

• Gastrointestinal disturbances (nausea, constipation, diarrhea, abdominal pain)
• Dark stools
• Staining of teeth (with liquid formulations)
• Allergic reactions (rare)

Interactions

• Antacids may reduce the absorption of iron
• Tetracycline antibiotics may interfere with iron absorption
• Ascorbic acid (vitamin C) may enhance iron absorption
• Certain foods and beverages (e.g., tea, coffee, dairy) can decrease iron absorption

Precautions

• Use with caution in patients with peptic ulcer disease
• Monitor for signs of iron overload
• Assess the cause of anemia before initiation of therapy
• Keep out of reach of children to prevent accidental overdose

Pregnancy

Ferrous sulfate is generally considered safe for use during pregnancy to prevent or treat iron-deficiency anemia.

Breast-feeding

Ferrous sulfate is excreted in breast milk in small amounts but is considered safe for breastfeeding mothers.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Ferrous sulfate 200 mg tablets
• Ferrous sulfate 325 mg modified-release tablets
• Ferrous sulfate oral solution 140 mg/5 mL
• Ferrous sulfate drops

Indications

• Vitamin B2 deficiency
• Isoniazid-induced neuropathy (prophylaxis and treatment)
• Metabolic diseases
• Cystathioninuria
• Homocystinuria
• Wilson's disease
• Prevention of penicillamine-induced neuropathy

Mechanism of action

Riboflavin acts as a precursor to flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are essential coenzymes in various enzymatic reactions. It binds to riboflavin hydrogenase, riboflavin kinase, and riboflavin synthase, facilitating the production of FMN and FAD. These coenzymes are critical for normal tissue respiration and energy metabolism, influencing hydrogen transport in oxidative enzyme systems such as cytochrome C reductase and succinic dehydrogenase. Moreover, riboflavin contributes to the antioxidant activity by aiding in the production of reduced glutathione, a key antioxidant in the body.

Pharmacodynamics

Riboflavin is an easily absorbed, water-soluble micronutrient that supports energy production by assisting in the metabolism of fats, carbohydrates, and proteins. It is vital for red blood cell formation, antibody production, and regulating growth and reproduction. The vitamin plays a significant role in maintaining healthy skin, nails, and hair, as well as supporting thyroid activity. Riboflavin also has therapeutic implications in preventing or treating various eye disorders, including cataracts.

Pharmacokinetics

Riboflavin is rapidly absorbed in the gastrointestinal tract, with its bioavailability influenced by dietary intake. It is primarily excreted through urine, with excess intake leading to bright yellow urine, which is a harmless side effect. The vitamin does not accumulate in the body, necessitating regular dietary intake to maintain adequate levels.

Adverse effects

• Urine discolouration
• Peripheral neuritis

Precautions

• With intravenous use, risk of cardiovascular collapse; resuscitation facilities must be available and monitor closely.

Pregnancy

Crosses the placenta but no adverse effects reported; information at high doses limited.

Breast-feeding

Present in breast milk but no adverse effects reported; information at high doses limited.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• 100 mg modified-release tablets
• 50 mg capsules
• 100 mg capsules
• 100 mg tablets
• Oral solution

Indications

• Vitamin B1 deficiency
• Wernicke-Korsakoff syndrome
• Beriberi
• Isoniazid-induced neuropathy (prophylaxis and treatment)
• Severe depletion or malabsorption of vitamins B and C

Dosage

Adults: For vitamin deficiency: 25–100 mg daily. For severe deficiency: 200–300 mg daily in divided doses. For

Mechanism of action

Thiamine functions primarily as a precursor for several phosphorylated active forms, which act as coenzymes in metabolic pathways. It reduces intracellular protein glycation by redirecting glycolytic flux and supports the synthesis of nucleic acids necessary for cell survival and proliferation. Additionally, thiamine has been shown to inhibit glucose-induced proliferation of endothelial cells, thus possibly playing a role in the modulation of vascular health.

Pharmacodynamics

Thiamine exhibits antioxidant properties and contributes to erythropoiesis, cognitive function, and mood regulation. It has protective effects against oxidative stress, particularly in neuronal tissues, where deficiency can lead to neuronal death due to increased free radical production. Thiamine also modulates glucose metabolism, influencing smooth muscle cell proliferation and potentially impacting the progression of atherosclerosis.

Pharmacokinetics

Thiamine is rapidly absorbed from the gastrointestinal tract, primarily in the jejunum, and is distributed throughout the body, with higher concentrations found in the liver, heart, and brain. It is excreted in urine, and its half-life is relatively short. The vitamin is converted into active forms within tissues, including thiamine diphosphate (TDP), which is the coenzyme form involved in carbohydrate metabolism. The body does not store significant amounts of thiamine, making regular dietary intake essential.

Adverse effects

• Allergic reactions
• Anaphylaxis (rare)
• Gastrointestinal disturbances

Precautions

• Facilities for treating anaphylaxis should be available when parenteral thiamine is administered
• Use with caution in patients with a history of hypersensitivity to thiamine

Pregnancy

Thiamine crosses the placenta but no adverse effects have been reported. Information regarding high doses is limited.

Breast-feeding

Severely thiamine-deficient mothers should avoid breast-feeding as thiamine is present in breast milk.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Thiamine hydrochloride 20 mg/ml oral solution
• Thiamine hydrochloride 50 mg tablets
• Thiamine hydrochloride 100 mg modified-release tablets
• Thiamine hydrochloride oral suspension

Indications

• Vitamin D deficiency
• Rickets
• Osteomalacia
• Osteoporosis
• Hypoparathyroidism

Dosage

Adults: The usual adult dose for vitamin D deficiency is 800 to 2000 IU daily, depending on the severity of deficiency and clinical condition. Higher doses may be used under medical supervision.

Mechanism of action

Cholecalciferol is converted to its active forms, 25-hydroxyvitamin D in the liver and 1,25-dihydroxyvitamin D in the kidneys. These metabolites enhance the intestinal absorption of calcium and phosphorus, increase serum calcium levels, and mobilize these minerals from bone. This process is regulated by parathyroid hormone, which influences calcium and phosphate metabolism, particularly in the kidneys.

Pharmacodynamics

The pharmacodynamics of cholecalciferol involve its conversion to active metabolites that play a significant role in calcium and phosphorus homeostasis. The metabolites facilitate intestinal absorption of these minerals, promote bone mineralization, and influence renal reabsorption. The onset of action occurs within 10 to 24 hours following administration, as metabolic activation is required for its biological effects.

Pharmacokinetics

Cholecalciferol is absorbed in the gastrointestinal tract, and its absorption is enhanced by the presence of dietary fats. It is transported in the bloodstream bound to vitamin D-binding protein. Once in the liver, it undergoes hydroxylation to form 25-hydroxyvitamin D, which is further converted in the kidneys to the active form, 1,25-dihydroxyvitamin D. The elimination half-life of cholecalciferol varies, typically spanning several days, and it is primarily excreted in bile and urine.

Adverse effects

• Hypercalcemia
• Hypercalciuria
• Nausea
• Vomiting
• Constipation
• Weakness
• Fatigue

Interactions

• May enhance the effects of thiazide diuretics, leading to increased risk of hypercalcemia
• Anticonvulsants may increase metabolism of vitamin D, leading to reduced effectiveness
• Cholestyramine may reduce absorption of vitamin D

Precautions

• Monitor serum calcium levels in patients with renal impairment
• Caution in patients with a history of hypercalcemia or hyperparathyroidism
• Use with caution in patients taking other medications that affect calcium metabolism

Pregnancy

Cholecalciferol can be used during pregnancy if indicated, as vitamin D is essential for fetal bone development.

Breast-feeding

Cholecalciferol is excreted in breast milk, but is generally considered safe during breastfeeding.

Storage

Store in a cool, dry place, away from light. Keep out of reach of children.

Formulations

• Capsules
• Tablets
• Liquid formulations

Indications

• Copper deficiency
• Occipital Horn Syndrome
• Menke's disease
• Contraception (via copper IUD)

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: Refer to the relevant clinical guidelines and BNF for specific dosing information.

Mechanism of action

Copper is absorbed from the gastrointestinal tract via high affinity copper uptake proteins and low affinity copper uptake proteins, likely being reduced to the Cu1+ form prior to transport. Inside enterocytes, it binds to the copper transport protein ATOX1, which facilitates its transport to copper transporting ATPase-1 on the Golgi membrane for incorporation into the Golgi apparatus. Once in systemic circulation, copper binds primarily to ceruloplasmin, albumin, and alpha 2-macroglobulin. It acts as a cofactor in a variety of oxidase enzymes and also influences sperm motility when released from copper IUDs, contributing to its contraceptive effect.

Pharmacodynamics

Copper is essential for the activity of many enzymes and plays a vital role in processes such as iron metabolism, neurotransmitter synthesis, and antioxidant defense. Copper ions, particularly when released from intrauterine devices, have been shown to decrease sperm viability, thereby impacting fertility.

Pharmacokinetics

Copper is absorbed from the gut and is predominantly transported in the plasma bound to proteins such as ceruloplasmin and albumin. The absorption efficiency can vary; however, a significant portion of dietary copper is usually absorbed. The body regulates copper levels through hepatic excretion and storage mechanisms, ensuring homeostasis. Excess copper can lead to toxicity, while deficiency results in various health issues.

Pregnancy

Copper is considered essential during pregnancy, but excessive intake should be avoided due to potential toxicity.

Breast-feeding

Copper is excreted in breast milk, and adequate maternal intake is important for infant development.

Storage

Store in a cool, dry place, away from moisture and heat.

Indications

• Copper deficiency
• Emetic agent in certain toxic ingestions
• Topical antiseptic in certain infections

Dosage

Children: Refer to established medical guidelines and literature for dosing information as specific doses can vary based on the condition being treated.

Adults: Refer to established medical guidelines and literature for dosing information as specific doses can vary based on the condition being treated.

Mechanism of action

Copper sulfate exhibits its effects primarily through the release of copper ions, which disrupt cellular processes in bacteria and fungi, leading to their death. The copper ions interfere with the electron transport chain and various enzyme systems, resulting in oxidative stress and cellular damage.

Pharmacodynamics

Copper is an essential trace element that plays a critical role in various biological processes, including the functioning of enzymes involved in redox reactions, iron metabolism, and the formation of connective tissues. However, excessive copper can be toxic, leading to gastrointestinal and neurological disturbances. The pharmacodynamic effects of copper sulfate are dose-dependent, with low doses being beneficial in deficiency states and higher doses exhibiting toxic effects.

Pharmacokinetics

Copper sulfate is absorbed in the gastrointestinal tract, with bioavailability influenced by the presence of food and other dietary components. Once absorbed, copper is transported in the bloodstream bound to ceruloplasmin and albumin. It is primarily excreted through the bile and urine. The half-life of copper in the body is variable, depending on individual metabolism and copper status. Chronic exposure can lead to accumulation and toxicity.

Contra-indications

• Hypersensitivity to copper or copper-containing products
• Severe renal impairment
• Acute or chronic liver disease

Adverse effects

• Gastrointestinal irritation
• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Copper toxicity
• Hepatotoxicity
• Metal fume fever
• Allergic reactions

Interactions

• May interact with agents that affect copper metabolism
• Antacids may decrease absorption of copper
• Zinc supplements may interfere with copper absorption

Precautions

• Use with caution in patients with liver disease
• Monitor for signs of copper toxicity
• Avoid use in patients with Wilson's disease

Pregnancy

Copper is an essential trace element, but excessive intake can be harmful. Consult relevant guidelines for use during pregnancy.

Breast-feeding

Copper is excreted in breast milk. Consult relevant guidelines for use during breastfeeding.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Copper sulfate pentahydrate

Indications

• Topical treatment of skin wounds
• Moisturizing dry skin
• Management of minor burns
• Soothing irritations and inflammation of the skin

Dosage

Children: Refer to the BNF for Children for specific dosing

Adults: Apply to the affected area as needed, following the specific product instructions.

Mechanism of action

Dexpanthenol is enzymatically converted to pantothenic acid, which is integral to the formation of coenzyme A. This coenzyme acts as a cofactor in numerous enzymatic reactions, particularly those related to protein metabolism in epithelial tissues. The topical application of dexpanthenol promotes fibroblast proliferation and accelerates wound healing through enhanced re-epithelialization. It also increases the availability of coenzyme A for acetylcholine synthesis, which can enhance intestinal motility by improving peristalsis.

Pharmacodynamics

Dexpanthenol, through its conversion to pantothenic acid, plays a vital role in the synthesis of coenzyme A, which is necessary for various metabolic processes, including the transfer of acetyl groups. It directly influences the production of acetylcholine, the neurotransmitter responsible for parasympathetic nervous system functions, which include maintaining normal intestinal activity. A deficiency in acetylcholine can lead to reduced peristalsis and conditions such as adynamic ileus.

Pharmacokinetics

Dexpanthenol is well absorbed when applied topically. It penetrates the skin effectively, reaching the underlying tissues where it can exert its biological effects. The metabolism of dexpanthenol involves its conversion to pantothenic acid, which further participates in the synthesis of coenzyme A. The elimination half-life and extent of systemic absorption vary based on the formulation and route of administration, but topical use typically results in low systemic exposure.

Adverse effects

• Skin irritation
• Allergic reactions

Precautions

• Use with caution in patients with known allergies to dexpanthenol or related compounds.

Pregnancy

Dexpanthenol is generally considered safe for use during pregnancy, but it is advisable to consult a healthcare provider before use.

Breast-feeding

Dexpanthenol is considered safe during breastfeeding, but consult a healthcare provider for specific recommendations.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Topical cream
• Topical ointment
• Topical solution

Indications

• Iron deficiency anemia
• Iron deficiency due to inadequate dietary intake
• Anemia associated with chronic disease
• Pregnancy-related anemia

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations based on age and weight.

Adults: Refer to the BNF for specific dosing recommendations, generally, adults may require 100-200 mg of elemental iron daily divided into several doses.

Mechanism of action

Ferrous ions (Fe2+) play a vital role in hemoglobin production by participating in the synthesis of heme, the iron-containing compound essential for oxygen transport in the blood. In addition, iron is a cofactor for various enzymes involved in metabolic pathways, including those related to DNA synthesis and energy production.

Pharmacodynamics

The pharmacodynamic effects of ferrous include increased hemoglobin synthesis, improved oxygen transport, and enhanced cellular energy metabolism. Supplementation leads to an increase in serum ferritin levels and replenishment of iron stores in the body, which is particularly beneficial in cases of iron deficiency anemia.

Pharmacokinetics

Ferrous iron is absorbed primarily in the duodenum and upper jejunum of the small intestine. The absorption rate can be influenced by various factors, including the presence of food, the form of iron, and individual patient characteristics. Once absorbed, ferrous is transported in the bloodstream bound to transferrin, and it is stored in the liver, spleen, and bone marrow as ferritin. The elimination half-life of iron is not well-defined as it is not excreted directly but rather recycled in the body.

Pregnancy

Not contraindicated, but iron supplementation should be done under medical supervision.

Breast-feeding

Iron is excreted in breast milk, but supplementation is generally considered safe.

Storage

Store in a cool, dry place away from sunlight. Keep out of reach of children.

Indications

• Lysine deficiency
• Support for immune function
• Management of herpes simplex virus outbreaks
• Enhancement of calcium absorption
• Support for collagen formation

Dosage

Children: Refer to specific guidelines or a healthcare professional for appropriate dosing. Doses can vary based on the condition being treated.

Adults: Refer to specific guidelines or a healthcare professional for appropriate dosing. Doses can vary based on the condition being treated.

Mechanism of action

Lysine acts by inhibiting the replication of the herpes simplex virus through competitive inhibition of arginine, an amino acid that the virus needs for its replication. By limiting arginine availability, lysine effectively reduces viral load and can help manage outbreaks.

Pharmacodynamics

Lysine is involved in the synthesis of proteins and plays a role in the production of enzymes, hormones, and antibodies. It is also involved in the formation of collagen, an essential component of connective tissues. The presence of lysine can enhance calcium absorption and retention, contributing to bone health.

Pharmacokinetics

Lysine is readily absorbed from the gastrointestinal tract and is distributed throughout the body tissues. Its bioavailability is high, with peak plasma concentrations occurring within 2-4 hours post-administration. The elimination half-life is variable but typically ranges around 2 hours, with lysine being primarily excreted unchanged in the urine.

Pregnancy

The effects of llysinemonohcl during pregnancy have not been adequately studied. It is advisable to avoid its use unless the potential benefits outweigh the risks.

Breast-feeding

Llysinemonohcl should be used with caution during breastfeeding due to limited data on its excretion in human milk.

Storage

Store at room temperature, away from moisture and light. Keep out of reach of children.

Indications

• Dermatitis
• Acne
• Rosacea
• Hyperpigmentation
• Skin aging

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines for paediatric patients.

Adults: Refer to the BNF for specific dosing guidelines based on the condition being treated.

Mechanism of action

Niacinamide functions primarily as a precursor to NAD and NADP, which are crucial for numerous enzymatic reactions in the body. It is involved in the NAD salvage pathway, which recycles nicotinamide for NAD synthesis. This process is vital for cellular energy production and metabolic processes. Niacinamide also has anti-inflammatory properties, which may contribute to its effects in skin health.

Pharmacodynamics

Niacinamide exhibits various pharmacological effects, including enhancing skin barrier function, reducing inflammation, and improving skin pigmentation. It has been shown to modulate keratinocyte function, improve collagen synthesis, and decrease the synthesis of sebum, thereby providing beneficial effects in conditions like acne and rosacea.

Pharmacokinetics

Niacinamide is readily absorbed from the gastrointestinal tract. It is distributed widely throughout the body and can cross biological membranes. The metabolism of niacinamide primarily occurs in the liver through methylation and conjugation, and it is excreted in urine as metabolites. The half-life of niacinamide is approximately 1-2 hours, and its effects can be prolonged due to its role in NAD synthesis.

Pregnancy

No evidence of harm, but use only if clearly needed.

Breast-feeding

Considered safe to use while breastfeeding.

Storage

Store in a cool, dry place away from light.

Formulations

• {'type': 'Topical cream', 'concentration': 'Various concentrations available'}
• {'type': 'Oral tablets', 'concentration': '100 mg, 250 mg, 500 mg'}

Indications

• Hyperthyroidism
• Thyroid storm
• Protection against radioactive iodine exposure
• Expectorant in respiratory conditions

Dosage

Children: Refer to the BNF for Children for specific paediatric dosing recommendations.

Adults: Refer to the BNF for specific dosing guidelines.

Mechanism of action

In hyperthyroid patients, potassium iodide inhibits the release of thyroid hormones into the circulation, resulting in rapid remission of symptoms. It reduces vascularity, firms glandular tissue, shrinks individual thyroid cells, promotes reaccumulation of colloid in follicles, and increases bound iodine levels. In radiation emergencies, it protects the thyroid gland by blocking the uptake of radioactive iodine isotopes, providing approximately 97% protection when administered prior to exposure.

Pharmacodynamics

Potassium iodide acts primarily in the thyroid gland by inhibiting thyroid hormone synthesis and release. This leads to reduced vascularity and firmer glandular tissue, smaller thyroid cells, reaccumulation of follicular colloid, and increased levels of bound iodine. Its protective effect against radioactive iodine isotopes minimizes the risk of radiation-induced thyroid neoplasms.

Pharmacokinetics

Potassium iodide is rapidly absorbed following oral administration. It distributes throughout the body with a particular affinity for the thyroid gland, where it exerts its effects. The elimination half-life varies, but it generally is excreted unchanged in urine. Dosage adjustments may be necessary in cases of renal impairment.

Contra-indications

• Hypersensitivity to potassium iodide or any component of the formulation
• Active thyroiditis or other forms of thyroid dysfunction not related to iodine deficiency
• Previous history of iodine-induced hyperthyroidism
• Radioactive iodine therapy within 4 weeks

Adverse effects

• Gastrointestinal disturbances including nausea, vomiting, and diarrhea
• Hypersensitivity reactions such as rashes, angioedema, and anaphylaxis
• Thyroid dysfunction including hyperthyroidism or hypothyroidism
• Iodism, characterized by metallic taste, sore gums, and skin lesions
• Fluid and electrolyte imbalances

Interactions

• May interact with other thyroid medications, enhancing their effects
• Anticoagulants may have altered effects when used with potassium iodide
• Concurrent use with lithium may increase the risk of thyroid dysfunction
• Other iodine-containing medications may increase the risk of adverse effects

Precautions

• Use with caution in patients with renal impairment
• Monitor thyroid function tests periodically during treatment
• Use with caution in patients with a history of thyroid disease
• Assess for possible interactions with other medications

Pregnancy

Potassium iodide should only be used in pregnancy when clearly needed, as excessive iodine can affect fetal thyroid function.

Breast-feeding

Potassium iodide is excreted in breast milk; caution is advised when administered to nursing mothers.

Storage

Store in a cool, dry place, protected from light. Keep out of reach of children.

Formulations

• Oral solution
• Tablets

Indications

• Vitamin B6 deficiency
• Peripheral neuropathy
• Anemia due to pyridoxine deficiency
• Supplementation in certain metabolic disorders
• Certain neurological conditions

Dosage

Children: Refer to the BNF for Children for specific dosages based on age and indication.

Adults: Refer to the BNF for specific dosages based on indication.

Mechanism of action

Pyridoxine is converted in the body to pyridoxal phosphate, the active form of vitamin B6, which serves as a coenzyme in various enzymatic reactions, particularly those involved in amino acid metabolism. It is involved in the synthesis of neurotransmitters such as serotonin, dopamine, and gamma-aminobutyric acid (GABA), influencing mood and cognitive function.

Pharmacodynamics

The pharmacodynamics of pyridoxine is closely linked to its role as a cofactor in enzymatic reactions. It participates in transamination, decarboxylation, and racemization of amino acids, and in the synthesis of neurotransmitters. Adequate levels of pyridoxine are essential for maintaining normal physiological functions, including the metabolism of carbohydrates and fats.

Pharmacokinetics

Pyridoxine is readily absorbed in the gastrointestinal tract after oral administration. It is widely distributed in body tissues, including the liver, muscle, and brain. The elimination half-life of pyridoxine varies but is typically around 15-20 days. It undergoes hepatic metabolism to form active metabolites, primarily pyridoxal phosphate. Excess pyridoxine is excreted in urine as metabolized products.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Headache
• Drowsiness
• Peripheral neuropathy (with high doses)
• Skin reactions (rare)

Interactions

• Levodopa (may reduce effectiveness)
• Phenobarbital (may alter metabolism)
• Isoniazid (may lead to deficiency)
• Oral contraceptives (may increase requirement)

Precautions

• Use with caution in patients with renal impairment
• Avoid high doses unless supervised by a healthcare provider
• Monitor for signs of neuropathy with prolonged use

Pregnancy

Pyridoxine is generally considered safe during pregnancy and may be used to manage nausea and vomiting.

Breast-feeding

Pyridoxine is excreted in breast milk, but it is considered safe for breastfeeding mothers when used in appropriate doses.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Tablets
• Injectable solutions
• Oral suspensions

Indications

• Thiamine deficiency
• Wernicke's encephalopathy
• Beriberi
• Alcoholism-related complications
• Certain metabolic disorders

Dosage

Children: Refer to BNF for Children for appropriate dosing information.

Adults: Refer to established clinical guidelines or BNF for specific dosing recommendations.

Mechanism of action

Thiamine is a coenzyme for several important enzymatic reactions, including the pyruvate dehydrogenase complex and alpha-ketoglutarate dehydrogenase. It is essential for converting carbohydrates into energy, facilitating the metabolism of glucose, and maintaining normal nerve function.

Pharmacodynamics

Thiamine deficiency leads to impaired carbohydrate metabolism, which can result in neurological and cardiovascular dysfunction. Supplementation with thiamine helps restore normal metabolic function and can alleviate symptoms associated with deficiency, such as Wernicke's encephalopathy and Beriberi. It also plays a role in the synthesis of neurotransmitters and in maintaining myelin integrity.

Pharmacokinetics

Thiamine is readily absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 1-2 hours after oral administration. It is distributed throughout the body, primarily in the liver, kidneys, and heart. Thiamine is metabolized in the liver to its active form, thiamine pyrophosphate. It has a biological half-life of about 9-18 days and is excreted primarily in the urine. Excess thiamine is excreted, making toxicity rare.

Adverse effects

• Allergic reactions
• Hypersensitivity reactions
• Gastrointestinal disturbances

Interactions

• May interact with certain diuretics, leading to altered thiamine levels

Precautions

• Use with caution in patients with renal impairment
• Monitor patients with a history of thiamine deficiency

Pregnancy

Thiamine is considered safe during pregnancy, as it is an essential nutrient.

Breast-feeding

Thiamine is excreted in breast milk, but supplementation is generally considered safe for breastfeeding mothers.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Thiamine hydrochloride injection
• Thiamine hydrochloride oral tablets
• Thiamine hydrochloride oral solution

Indications

• Vitamin E deficiency
• Prevention of oxidative stress-related conditions
• Adjunct therapy in chronic diseases such as coronary heart disease
• Potential protective role against certain cancers

Dosage

Children: Refer to BNF for Children for appropriate dosing in pediatric populations.

Adults: Refer to specific BNF guidelines for adult dosing of vitamin E.

Mechanism of action

Vitamin E functions primarily as an antioxidant, preventing free radical reactions with cell membranes. It terminates lipid peroxidation by reacting with unstable lipid radicals to form stable lipids and a relatively stable vitamin E radical. This radical can be regenerated back to its active form by ascorbate or glutathione. Additionally, vitamin E may have effects on inflammation and cancer progression through its influence on NF-kappaB signaling pathways.

Pharmacodynamics

Vitamin E protects cells from oxidative stress by neutralizing free radicals, thus preventing cellular damage. It is particularly important for the protection of lipids and fat-soluble vitamins, such as vitamins A and B, from oxidative degradation. Vitamin E deficiency can lead to increased susceptibility to oxidative damage, contributing to conditions such as coronary heart disease and certain types of cancer.

Pharmacokinetics

Vitamin E is absorbed in the intestine and transported via lipoproteins in the bloodstream. It is stored primarily in adipose tissue and the liver. The metabolism of vitamin E involves its conversion to various metabolites, which can be excreted in urine. Bioavailability may be affected by dietary fat intake, as it is a fat-soluble vitamin.

Adverse effects

• Nausea
• Diarrhea
• Fatigue
• Abdominal cramps
• Headache

Interactions

• Anticoagulants may have increased effects
• Cholestyramine may decrease absorption of vitamin E
• Certain chemotherapy agents may interact

Precautions

• Monitor for bleeding if on anticoagulants
• Caution in patients with liver disease
• Assess for vitamin E deficiency in at-risk populations

Pregnancy

Vitamin E is generally considered safe during pregnancy when taken in recommended amounts; however, excessive doses should be avoided.

Breast-feeding

Vitamin E is excreted in breast milk; usual dietary intake is generally considered safe while breastfeeding.

Storage

Store in a cool, dry place away from light. Keep container tightly closed.

Formulations

• Capsules
• Softgels
• Tablets
• Oil solutions

Indications

• Zinc deficiency
• Wound healing
• Diarrhea in children
• Acne
• Common cold
• Immune support

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines based on the child's age, weight, and condition.

Adults: Refer to the BNF for specific dosing guidelines based on the condition being treated and the formulation used.

Mechanism of action

Zinc sulfate provides zinc ions (Zn²⁺) that are essential for numerous biological processes. Zinc acts as a cofactor for many enzymes, facilitating various biochemical reactions. It also plays a role in modulating immune responses, promoting the activity of T-lymphocytes, and influencing the production of cytokines. Furthermore, zinc is vital for maintaining structural integrity in proteins and cell membranes.

Pharmacodynamics

The pharmacodynamic effects of zinc sulfate primarily relate to its role in enzymatic functions and immune modulation. Zinc deficiency can impair immune function, leading to increased susceptibility to infections. Supplementation with zinc sulfate can enhance immune responses, improve wound healing, and contribute to overall health by restoring normal zinc levels in the body. Additionally, zinc has antioxidant properties, helping to combat oxidative stress.

Pharmacokinetics

Zinc sulfate is absorbed in the gastrointestinal tract, with an absorption rate that can vary based on the presence of food and other dietary factors. Peak plasma concentrations are typically reached within 2 to 3 hours after oral administration. Zinc is distributed throughout the body, particularly in skeletal muscle, bone, and the liver. The elimination half-life of zinc from the body is approximately 2 to 3 days, and it is primarily excreted through the kidneys and gastrointestinal tract.

Contra-indications

• Hypersensitivity to zinc sulfate or any component of the formulation
• Severe renal impairment

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Metallic taste
• Headache
• Drowsiness
• Fatigue

Interactions

• Antibiotics (e.g., tetracyclines and quinolones) - zinc may impair absorption
• Copper supplements - excessive zinc can lead to copper deficiency

Precautions

• Use with caution in patients with renal impairment
• Avoid high doses in patients with conditions requiring low zinc intake
• Monitor for signs of zinc toxicity, especially with prolonged use

Pregnancy

Zinc is essential during pregnancy for proper fetal development, but supplementation should be done under medical guidance to avoid excessive intake.

Breast-feeding

Zinc is secreted in breast milk, and supplementation should be discussed with a healthcare provider to ensure adequate maternal and infant intake.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Oral tablets
• Oral solution
• Effervescent tablets
• Syrup

Mechanism of action

Vitamin B12 serves as a cofactor for _methionine synthase_ and _L-methylmalonyl-CoA mutase_ enzymes. Methionine synthase is essential for the synthesis of purines and pyrimidines that form DNA. L-methylmalonyl-CoA mutase converts L-methylmalonyl-CoA to _succinyl-CoA_ in the degradation of propionate, an important reaction required for both fat and protein metabolism. It is a lack of vitamin B12 cofactor in the above reaction and the resulting accumulation of methylmalonyl CoA that is believed to be responsible for the neurological manifestations of B12 deficiency. Succinyl-CoA is also necessary for the synthesis of hemoglobin. In tissues, vitamin B12 is required for the synthesis of _methionine_ from homocysteine. Methionine is required for the formation of S-adenosylmethionine, a methyl donor for nearly 100 substrates, comprised of DNA, RNA, hormones, proteins, as well as lipids. Without vitamin B12, tetrahydrofolate cannot be regenerated from 5-methyltetrahydrofolate, and this can lead to functional folate deficiency,. This reaction is dependent on methylcobalamin (vitamin B12) as a co-factor and is also dependent on folate, in which the methyl group of methyltetrahydrofolate is transferred to homocysteine to form _methionine_ and _tetrahydrofolate_. Vitamin B12 incorporates into circulating folic acid into growing red blood cells; retaining the folate in these cells. A deficiency of vitamin B12 and the interruption of this reaction leads to the development of megaloblastic anemia.

Pharmacodynamics

**General effects** Cyanocobalamin corrects vitamin B12 deficiency and improves the symptoms and laboratory abnormalities associated with pernicious anemia (megaloblastic indices, gastrointestinal lesions, and neurologic damage). This drug aids in growth, cell reproduction, hematopoiesis, nucleoprotein, and myelin synthesis. It also plays an important role in fat metabolism, carbohydrate metabolism, as well as protein synthesis. Cells that undergo rapid division (for example, epithelial cells, bone marrow, and myeloid cells) have a high demand for vitamin B12. **Parenteral cyanocobalamin effects** The parenteral administration of vitamin B12 rapidly and completely reverses the megaloblastic anemia and gastrointestinal symptoms of vitamin B12 deficiency. Rapid parenteral administration of vitamin B12 in deficiency related neurological damage prevents the progression of this condition. **Nasal spray effects** In 24 vitamin B12 deficient patients who were already stabilized on intramuscular (IM) vitamin B12 therapy, single daily doses of intranasal cyanocobalamin for 8 weeks lead to serum vitamin B12 concentrations that were within the target therapeutic range (>200 ng/L).

Mechanism of action

Iron is necessary for the production of hemoglobin. Iron-deficiency can lead to decreased production of hemoglobin and a microcytic, hypochromic anemia.

Pharmacodynamics

The major activity of supplemental iron is in the prevention and treatment of iron deficiency anemia. Iron has putative immune-enhancing, anticarcinogenic and cognition-enhancing activities.

Mechanism of action

Iron is necessary for the production of hemoglobin. Iron-deficiency can lead to decreased production of hemoglobin and a microcytic, hypochromic anemia.

Pharmacodynamics

The major activity of supplemental iron is in the prevention and treatment of iron deficiency anemia. Iron has putative immune-enhancing, anticarcinogenic and cognition-enhancing activities.

Mechanism of action

Binds to riboflavin hydrogenase, riboflavin kinase, and riboflavin synthase. Riboflavin is the precursor of flavin mononucleotide (FMN, riboflavin monophosphate) and flavin adenine dinucleotide (FAD). The antioxidant activity of riboflavin is principally derived from its role as a precursor of FAD and the role of this cofactor in the production of the antioxidant reduced glutathione. Reduced glutathione is the cofactor of the selenium-containing glutathione peroxidases among other things. The glutathione peroxidases are major antioxidant enzymes. Reduced glutathione is generated by the FAD-containing enzyme glutathione reductase. Riboflavin is converted to 2 coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are necessary for normal tissue respiration. Riboflavin is also required for activation of pyridoxine, conversion of tryptophan to niacin, and may be involved in maintaining erythrocyte integrity. Riboflavin functions as the coenzyme for flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), which primarily influence hydrogen transport in oxidative enzyme systems (eg, cytochrome C reductase, succinic dehydrogenase, xanthine oxidase). Two active forms of riboflavin exist ... coenzyme flavin mononucleotide (FMN) and coenzyme flavin adenine dinucleotide (FAD). They are formed by reaction of riboflavin with 1 and 2 molecules of ATP as follow: riboflavin + ATP = riboflavin-P (FMN) + ADP; FMN + ATP = riboflavin-ADP (FAD) + PP. Riboflavin is a water-soluble, yellow, fluorescent compound. The primary form of the vitamin is as an integral component of the coenzymes flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD). It is in these bound coenzyme forms that riboflavin functions as a catalyst for redox reactions in numerous metabolic pathways and in energy production. ... The redox reactions in which flavocoenzymes participate include flavoprotein-catalyzed dehydrogenations that are both pyridine nucleotide (niacin) dependent and independent, reactions with sulfur-containing compounds, hydroxylations, oxidative decarboxylations (involving thiamin as its pyrophosphate), dioxygenations, and reduction of oxygen to hydrogen peroxide. There are obligatory roles of flavocoenzymes in the formation of some vitamins and their coenzymes. For example, the biosynthesis of two niacin-containing coenzymes from tryptophan occurs via FAD-dependent kynurenine hydroxylase, an FMN-dependent oxidase catalyzes the conversion of the 5'-phosphates of vitamin B6 to coenzymic pyridoxal 5'-phosphate, and an FAD-dependent dehydrogenase reduces 5,10-methylene-tetrahydrofolate to the 5'-methyl product that interfaces with the B12-dependent formation of methionine from homocysteine and thus with sulfur amino acid metabolism. For more Mechanism of Action (Complete) data for Riboflavin (7 total), please visit the HSDB record page.

Pharmacodynamics

Riboflavin or vitamin B2 is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, it supports energy production by aiding in the metabolising of fats, carbohydrates, and proteins. Vitamin B2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin also helps in the prevention or treatment of many types of eye disorders, including some cases of cataracts.

Mechanism of action

It is thought that the mechanism of action of thiamine on endothelial cells is related to a reduction in intracellular protein glycation by redirecting the glycolytic flux. Thiamine is mainly the transport form of the vitamin, while the active forms are phosphorylated thiamine derivatives. Natural derivatives of thiamine phosphate, such as thiamine monophosphate (ThMP), thiamine diphosphate (ThDP), also sometimes called thiamine pyrophosphate (TPP), thiamine triphosphate (ThTP), and thiamine triphosphate (AThTP), that act as coenzymes in addition to their each unique biological functions. Metabolic control analysis predicts that stimulators of transketolase enzyme synthesis such as thiamin (vitamin B-1) support a high rate of nucleic acid ribose synthesis necessary for tumor cell survival, chemotherapy resistance, and proliferation. Metabolic control analysis also predicts that transketolase inhibitor drugs will have the opposite effect on tumor cells. This may have important implications in the nutrition and future treatment of patients with cancer.

Pharmacodynamics

Thiamine is a vitamin with antioxidant, erythropoietic, cognition-and mood-modulatory, antiatherosclerotic, putative ergogenic, and detoxification activities. Thiamine has been found to protect against lead-induced lipid peroxidation in rat liver and kidney. Thiamine deficiency results in selective neuronal death in animal models. The neuronal death is associated with increased free radical production, suggesting that oxidative stress may play an important early role in brain damage associated with thiamine deficiency. Thiamine plays a key role in intracellular glucose metabolism and it is thought that thiamine inhibits the effect of glucose and insulin on arterial smooth muscle cell proliferation. Inhibition of endothelial cell proliferation may also promote atherosclerosis. Endothelial cells in culture have been found to have a decreased proliferative rate and delayed migration in response to hyperglycemic conditions. Thiamine has been shown to inhibit this effect of glucose on endothelial cells.

Mechanism of action

Most individuals naturally generate adequate amounts of vitamin D through ordinary dietary intake of vitamin D (in some foods like eggs, fish, and cheese) and natural photochemical conversion of the vitamin D3 precursor 7-dehydrocholesterol in the skin via exposure to sunlight. Conversely, vitamin D deficiency can often occur from a combination of insufficient exposure to sunlight, inadequate dietary intake of vitamin D, genetic defects with endogenous vitamin D receptor, or even severe liver or kidney disease. Such deficiency is known for resulting in conditions like rickets or osteomalacia, all of which reflect inadequate mineralization of bone, enhanced compensatory skeletal demineralization, resultant decreased calcium ion blood concentrations, and increases in the production and secretion of parathyroid hormone. Increases in parathyroid hormone stimulate the mobilization of skeletal calcium and the renal excretion of phosphorus. This enhanced mobilization of skeletal calcium leads towards porotic bone conditions. Ordinarily, while vitamin D3 is made naturally via photochemical processes in the skin, both itself and vitamin D2 can be found in various food and pharmaceutical sources as dietary supplements. The principal biological function of vitamin D is the maintenance of normal levels of serum calcium and phosphorus in the bloodstream by enhancing the efficacy of the small intestine to absorb these minerals from the diet. At the liver, vitamin D3 or D2 is hydroxylated to 25-hydroxyvitamin D and then finally to the primary active metabolite 1,25-dihydroxyvitamin D in the kidney via further hydroxylation. This final metabolite binds to endogenous vitamin d receptors, which results in a variety of regulatory roles - including maintaining calcium balance, the regulation of parathyroid hormone, the promotion of the renal reabsorption of calcium, increased intestinal absorption of calcium and phosphorus, and increased calcium and phosphorus mobilization of calcium and phosphorus from bone to plasma to maintain balanced levels of each in bone and the plasma. In particular, calcitriol interacts with vitamin D receptors in the small intestine to enhance the efficiency of intestinal calcium and phosphorous absorption from about 10-15% to 30-40% and 60% increased to 80%, respectively. Furthermore, calcitriol binds with vitamin D receptors in osteoblasts to stimulate a receptor activator of nuclear factor kB ligand (or RANKL) which subsequently interacts with receptor activator of nuclear factor kB (NFkB) on immature preosteoclasts, causing them to become mature bone-resorbing osteoclasts. Such mature osteoclasts ultimately function in removing calcium and phosphorus from bone to maintain blood calcium and phosphorus levels. Moreover, calcitriol also stimulates calcium reabsorption from the glomerular filtrate in the kidneys. Additionally, it is believed that when calcitriol binds with nuclear vitamin D receptors, that this bound complex itself binds to retinoic acid X receptor (RXR) to generate a heterodimeric complex that consequently binds to specific nucleotide sequences in the DNA called vitamin D response elements. When bound, various transcription factors attach to this complex, resulting in either up or down-regulation of the associated gene's activity. It is thought that there may be as much as 200 to 2000 genes that possess vitamin D response elements or that are influenced indirectly to control a multitude of genes across the genome. It is in this way that cholecalciferol is believed to function in regulating gene transcription associated with cancer risk, autoimmune disorders, and cardiovascular disease linked to vitamin D deficiency. In fact, there has been some research to suggest calcitriol may also be able to prevent malignancies by inducing cellular maturation and inducing apoptosis and inhibiting angiogenesis, exhibit anti-inflammatory effects by inhibiting foam cell formation and promoting angiogenesis in en

Pharmacodynamics

The in vivo synthesis of the predominant two biologically active metabolites of vitamin D occurs in two steps. The first hydroxylation of vitamin D3 cholecalciferol (or D2) occurs in the liver to yield 25-hydroxyvitamin D while the second hydroxylation happens in the kidneys to give 1, 25-dihydroxyvitamin D. These vitamin D metabolites subsequently facilitate the active absorption of calcium and phosphorus in the small intestine, serving to increase serum calcium and phosphate levels sufficiently to allow bone mineralization. Conversely, these vitamin D metabolites also assist in mobilizing calcium and phosphate from bone and likely increase the reabsorption of calcium and perhaps also of phosphate via the renal tubules. There exists a period of 10 to 24 hours between the administration of cholecalciferol and the initiation of its action in the body due to the necessity of synthesis of the active vitamin D metabolites in the liver and kidneys. It is parathyroid hormone that is responsible for the regulation of such metabolism at the level of the kidneys.

Mechanism of action

Copper is absorbed from the gut via high affinity copper uptake protein and likely through low affinity copper uptake protein and natural resistance-associated macrophage protein-2. It is believed that copper is reduced to the Cu1+ form prior to transport. Once inside the enterocyte, it is bound to copper transport protein ATOX1 which shuttles the ion to copper transporting ATPase-1 on the golgi membrane which take up copper into the golgi apparatus. Once copper has been secreted by enterocytes into the systemic circulation it remain largely bound by ceruloplasmin (65-90%), albumin (18%), and alpha 2-macroglobulin (12%). Copper is an essential element in the body and is incorporated into many oxidase enzymes as a cofactor. It is also a component of zinc/copper super oxide dismutase, giving it an anti-oxidant role. Copper defiency occurs in Occipital Horn Syndrome and Menke's disease both of which are associated with impaired development of connective tissue due to the lack of copper to act as a cofactor in protein-lysine-6-oxidase. Menke's disease is also associated with progressive neurological impairment leading to death in infancy. The precise mechanisms of the effects of copper deficiency are vague due to the wide range of enzymes which use the ion as a cofactor. Copper appears to reduce the viabilty and motility of spermatozoa. This reduces the likelihood of fertilization with a copper IUD, producing copper's contraceptive effect. The exact mechanism of copper's effect on sperm are unknown. The reason for the less severe reaction when the foreign body is at a distance from the retina has been proposed to be ... that near the retina & its blood vessels there is greater oxygen tension than at a distance, which causes metallic copper to oxidize to toxic copper compounds more rapidly close to or in contact with the retina than at a distance. Furthermore, the abscess formation that is characteristic of copper undergoing oxidation close to the retina & choroiod can be attributed to attraction of polymorphonuclear leukocytes from these nearby vascular tissues, which become heavily infiltrated. Liquefaction & disorganization of the vitreous body has been explained on the basis of copper catalysis of oxidation of ascorbic acid, leading to depolymerization of the hyaluronic acid of the vitreous humor. Changes in protein & hexosamine content have also been related to decrease in viscosity of the vitreous humor. Increased content of amino acids in the vitreous humor has been consistent with proteolysis of the vitreous body, but decreased concentration in the aqueous humor has suggested suppression of secretion of amino acids by the ciliary body under the influence of copper.

Pharmacodynamics

Copper is incorporated into many enzymes throughout the body as an essential part of their function. Copper ions are known to reduce fertility when released from copper-containing IUDs.

Mechanism of action

Dexpanthenol is an alcohol derivative of pantothenic acid, a component of the B complex vitamins and an essential component of a normally functioning epithelium. Dexpanthenol is enzymatically cleaved to form pantothenic acid, which is an essential component of Coenzyme A, which acts as a cofactor in many enzymatic reactions that are important for protein metabolism in the epithelium. Dermatological effects of the topical use of dexpanthenol include increased fibroblast proliferation and accelerated re-epithelialization in wound healing. Furthermore, it acts as a topical protectant, moisturizer, and has demonstrated anti-inflammatory properties. This alcohol ... is said to increase the amount of coenzyme A available for the synthesis of acetylcholine. Increased formation of acetylcholine is thought to increase peristalsis and intestinal tone. ... To test the functional effect of pantothenate on dermal fibroblasts, cells were cultured and in vitro proliferation tests were performed using a standardized scratch test procedure. For all three donors analyzed, a strong stimulatory effect of pantothenate at a concentration of 20 ug/mL on the proliferation of cultivated dermal fibroblasts was observed. To study the molecular mechanisms resulting in the proliferative effect of pantothenate, gene expression was analyzed in dermal fibroblasts cultivated with 20 ug/mL of pantothenate compared with untreated cells using the GeneChip Human Exon 1.0 ST Array. A number of significantly regulated genes were identified including genes coding for interleukin (IL)-6, IL-8, Id1, HMOX-1, HspB7, CYP1B1 and MARCH-II. Regulation of these genes was subsequently verified by quantitative real-time polymerase chain reaction analysis. Induction of HMOX-1 expression by pantothenol and pantothenic acid in dermal cells was confirmed on the protein level using immunoblots. Functional studies revealed the enhanced suppression of free radical formation in skin fibroblasts cultured with panthenol. In conclusion, these studies provided new insight in the molecular mechanisms linked to the stimulatory effect of pantothenate and panthenol on the proliferation of dermal fibroblasts. /Calcium pantotenate/ ... Pantothenic acid, pantothenol and other derivatives ... are precursors of CoA /that/ protect cells and whole organs against peroxidative damage by increasing the content of cell glutathione...

Pharmacodynamics

Pantothenic acid is a precursor of coenzyme A, which serves as a cofactor for a variety of enzyme-catalyzed reactions involving transfer of acetyl groups. The final step in the synthesis of acetylcholine consists of the choline acetylase transfer of acetyl group from acetylcoenzyme A to choline. Acetylcholine is the neurohumoral transmitter in the parasympathetic system and as such maintains the normal functions of the intestine. Decrease in acetylcholine content would result in decreased peristalsis and in extreme cases adynamic ileus.

Mechanism of action

In hyperthyroid patients, potassium iodide produces rapid remission of symptoms by inhibiting the release of thyroid hormone into the circulation. The effects of potassium iodide on the thyroid gland include reduction of vascularity, a firming of the glandular tissue, shrinkage of the size of individual cells, reaccumulation of colloid in the follicles, and increases in bound iodine. These actions may facilitate thyroidectomy when the medication is given prior to surgery. When administered prior to and following administration of radioactive isotopes and in radiation emergencies involving the release of radioactive iodine, potassium iodide protects the thyroid gland by blocking the thyroidal uptake of radioactive isotopes of iodine. The mechanism of action of potassium iodide's antifungal activity against Sporothix schenckii has not been determined. Potassium iodide does not appear to increase monocyte or neutrophil killing of S. schenckii in in vitro studies. However, exposure of the yeast form of S. schenckii to various concentrations of iodine (iodine and potassium iodide solution) has resulted in rapid cell destruction. Potassium iodide is thought to act as an expectorant by increasing respiratory tract secretions and thereby decreasing the viscosity of mucous ... When potassium iodide is administered simultaneously with radiation exposure, the protectant effect is approximately 97%. Potassium iodide given 12 and 24 hours before exposure yields a 90% and 70% protectant effect, respectively. However, potassium iodide administered 1 and 3 hours after exposure results in an 85% and 50% protectant effect, respectively. Potassium iodide administered more than 6 hours after exposure is thought to have a negligible protectant effect.

Pharmacodynamics

It works in the thyroid gland. By inhibiting thyroid hormone synthesis and release, thyroid gland vascularity is reduced, thyroid gland tissue becomes firmer, thyroid cell size is reduced, follicular colloid reaccumulates, and bound iodine levels increase. As a protectant following radiation exposure, KI blocks the uptake of radioactive iodine isotopes by the thyroid gland thereby minimizing the risk of radiation-induced thyroid neoplasms.

Mechanism of action

The mechanism of action for most of vitamin E's effects are still unknown. Vitamin E is an antioxidant, preventing free radical reactions with cell membranes. Though in some cases vitamin E has been shown to have pro-oxidant activity. One mechanism of vitamin E's antioxidant effect is in the termination of lipid peroxidation. Vitamin E reacts with unstable lipid radicals, producing stable lipids and a relatively stable vitamin E radical. The vitamin E radical is then reduced back to stable vitamin E by reaction with ascorbate or glutathione. Cancer development and progression are closely associated with inflammation. NF-kappaB (nuclear factor kappaB) provides a mechanistic link between inflammation and cancer, and is a major factor controlling the ability of malignant cells to resist tumor surveillance mechanisms. NF-kappaB might also regulate tumor angiogenesis and invasiveness and the signalling pathways that mediate its activation provide attractive targets for new chemopreventive and chemotherapeutic approaches. ROS (reactive oxygen species) initiate inflammation by up-regulation of pro-inflammatory cytokines and therefore antioxidants provide a major defence against inflammation. alpha-Tocopherol is a lipid-soluble antioxidant. In addition to decreasing lipid peroxidation, alpha-tocopherol may exert intracellular effects. Hence, the aim of this study was to test the effect of alpha-tocopherol supplementation in cancer prevention via suppression of NF-kappaB-mediated pro-inflammatory cytokines. alpha-Tocopherol treatment significantly down-regulates expression, synthesis as well as secretion of pro-inflammatory cytokine IL-6 (interleukin-6) in cancerous mice. It also suppresses NF-kappaB binding to IL-6 promoter in liver leading to decreased secretion of IL-6 in serum. The regulation of the signalling pathway by alpha-tocopherol is found apart from its antioxidant capacity to reduce lipid peroxidation. Thus, the present study provides evidence for the hypothesis that besides the powerful free radical scavenging effects, alpha-tocopherol has genomic effects in down-regulation of pro-inflammatory cytokine and cancer prevention via the NF-kappaB-dependent pathway. Mitocans are drugs selectively killing cancer cells by destabilizing mitochondria and many induce apoptosis via generation of reactive oxygen species (ROS). However, the molecular events by which ROS production leads to apoptosis has not been clearly defined. In this study with the mitocan alpha-tocopheryl succinate (alpha-TOS) the role of the Bcl-2 family proteins in the mechanism of malignant cell apoptosis has been determined. Exposure of several different cancer cell lines to alpha-TOS increased expression of the Noxa protein, but none of the other proteins of the Bcl-2 family, an event that was independent of the cellular p53 status. alpha-TOS caused a profound conformational change in the pro-apoptotic protein, Bak, involving oligomerization in all cell types, and this also applied to the Bax protein, but only in non-small cell lung cancer cells. Immunoprecipitation studies indicated that alpha-TOS activates the two BH1-3 proteins, Bak or Bax, to form high molecular weight complexes in the mitochondria. RNAi knockdown revealed that Noxa and Bak are required for alpha-TOS-induced apoptosis, and the role of Bak was confirmed using Bak- and/or Bax-deficient cells. We conclude that the major events induced by alpha-TOS in cancer cells downstream of ROS production leading to mitochondrial apoptosis involve the Noxa-Bak axis. It is proposed that this represents a common mechanism for mitochondrial destabilization activated by a variety of mitocans that induce accumulation of ROS in the early phases of apoptosis. /alpha-Tocopheryl succinate/

Pharmacodynamics

Vitamin E is a collective term used to describe 8 separate fat soluble antioxidants, most commonly alpha-tocopherol. Vitamin E acts to protect cells against the effects of free radicals, which are potentially damaging by-products of the body's metabolism. Vitamin E deficiency is seen in persons with abetalipoproteinemia, premature, very low birth weight infants (birth weights less than 1500 grams, or 3½ pounds), cystic fibrosis, and cholestasis and severe liver disease. Preliminary research suggests vitamin E may help prevent or delay coronary heart disease and protect against the damaging effects of free radicals, which may contribute to the development of chronic diseases such as cancer. It also protects other fat-soluble vitamins (A and B group vitamins) from destruction by oxygen. Low levels of vitamin E have been linked to increased incidence of breast and colon cancer.