JARIFAN -2

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

• Papulopustular rosacea
• Inflammatory acne vulgaris

Dosage

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

Adults: For papulopustular rosacea, apply daily for up to 4 months. The treatment course may be repeated; discontinue if no improvement is observed after 3 months. For inflammatory acne vulgaris, apply twice daily, reduced to once daily or alternate days if irritation occurs.

Mechanism of action

Nicotinamide exhibits anti-inflammatory effects by inhibiting the release of pro-inflammatory cytokines and enhancing the barrier function of the skin. It is also involved in the NAD salvage pathway, which is essential for maintaining cellular energy levels and promoting cell repair mechanisms. Additionally, nicotinamide contributes to the synthesis of coenzymes involved in metabolic processes, including the conversion of niacin into NAD+.

Pharmacodynamics

Nicotinamide is known for its ability to improve skin hydration and reduce transepidermal water loss. It has been shown to decrease the appearance of acne lesions and rosacea by modulating inflammatory responses and accelerating cell turnover. Its antioxidant properties also help to protect the skin from oxidative stress and UV damage.

Pharmacokinetics

When applied topically, nicotinamide is absorbed through the skin layers, with minimal systemic absorption. Its peak plasma concentrations are generally low, and the drug has a half-life that varies depending on the route of administration. The metabolism of nicotinamide occurs primarily in the liver, where it is converted into its active forms, including NAD+. The elimination route is via the kidneys, with metabolites excreted in urine.

Contra-indications

• Pregnancy
• Severe acne involving large areas
• Severe skin reactions

Adverse effects

• Sunburn
• Skin reactions (common or very common)
• Cheilitis
• Eyelid oedema
• Flushing
• Dry skin
• Eye irritation
• Photosensitivity reactions
• Transient skin pigmentation changes

Interactions

• Clindamycin
• Topical retinoids
• Abrasive cleaners
• Comedogenic cosmetics

Precautions

• Avoid exposure to UV light, including sunlight and sunlamps
• Wash hands immediately after use
• Avoid contact with eyes and mucous membranes
• Use moisturizers to reduce the risk of skin irritation
• Discontinue treatment if severe irritation occurs

Pregnancy

Avoid use during pregnancy due to potential risks, as limited information is available regarding toxicity.

Breast-feeding

Amount of drug in milk after topical application is probably too small to be harmful; ensure infant does not come in contact with treated areas.

Storage

Store at room temperature away from moisture and light.

Formulations

• Cream
• Gel

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

• 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

• Pantothenic acid deficiency
• Supplementation for improved energy metabolism
• Support for adrenal function
• As part of a balanced diet

Dosage

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

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

D-Pantothenate is converted into coenzyme A (CoA) in the body. CoA is vital for the metabolism of carbohydrates, fats, and proteins, facilitating the transfer of acyl groups in various biochemical reactions. This action is crucial for the synthesis and degradation of fatty acids, as well as the metabolism of pyruvate and the Krebs cycle.

Pharmacodynamics

As a water-soluble vitamin, D-Pantothenate is involved in numerous physiological functions, including energy production, the synthesis of neurotransmitters, and the generation of steroid hormones. It aids in the conversion of fats and carbohydrates into energy, and it plays a role in maintaining healthy skin and hair.

Pharmacokinetics

D-Pantothenate is absorbed in the intestines and is widely distributed throughout the body. It is excreted primarily in the urine, with very little stored in the body. The half-life of pantothenic acid in the plasma is relatively short, necessitating regular dietary intake. Excessive amounts are typically excreted without significant toxicity.

Pregnancy

D Pantothenate is generally considered safe during pregnancy as it is a vitamin and essential for fetal development, but consultation with a healthcare provider is advised.

Breast-feeding

D Pantothenate is excreted in breast milk but is considered safe for breastfeeding mothers.

Storage

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

Formulations

• D Pantothenate 500 mg tablets
• D Pantothenate 250 mg capsules

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

• Folate deficiency
• Megaloblastic anemia
• Prevention of neural tube defects in pregnancy
• Supplementation in patients on certain medications (e.g., methotrexate)

Dosage

Children: Refer to the BNF for Children for appropriate pa

Adults: Refer to specific guidelines or the BNF for appropriate adult dosing based on the indication.

Mechanism of action

Folate functions as a coenzyme in the conversion of homocysteine to methionine, a process that is vital for DNA synthesis and repair. It is involved in the one-carbon metabolism pathway, where it acts as a carrier of one-carbon units necessary for the synthesis of purines and thymidylate, thus supporting the production of nucleotides and DNA. This mechanism is particularly important in rapidly dividing cells.

Pharmacodynamics

Folate is critical for the formation of red blood cells and the proper functioning of the nervous system. It aids in the production of nucleic acids, which are essential for cell proliferation. Folate deficiency can lead to impaired DNA synthesis, resulting in megaloblastic anemia characterized by the presence of large, immature red blood cells in the bloodstream. Adequate folate levels are also associated with reduced risk of neural tube defects in developing fetuses.

Pharmacokinetics

Folate is absorbed in the proximal part of the small intestine, primarily in the jejunum, and is transported in the bloodstream bound to plasma proteins. It undergoes hepatic metabolism and is stored mainly in the liver. The elimination half-life varies, but dietary folate can be retained in the body for several weeks. Excess folate is excreted through the urine. The bioavailability of folate from food sources is lower compared to synthetic folic acid found in supplements.

Interactions

• folates+fluorouracil: Severe (increases risk of toxicity)
• folates+antiepileptics: Moderate (decreases concentration)
• folates+fosphenytoin: Moderate (decreases concentration)
• folates+phenobarbital: Moderate (decreases concentration)
• folates+phenytoin: Moderate (decreases concentration)
• folates+primidone: Moderate (decreases concentration)
• sulfasalazine+folates: Unknown (decreases absorption)

Pregnancy

Folate is essential for fetal development and is often recommended to prevent neural tube defects.

Breast-feeding

Folate is generally safe during breastfeeding, as it is important for both maternal and infant health.

Storage

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

Formulations

• Tablets
• Injection

Dosage

Children: Refer to official dosing guidelines for paediatric indications and dosages.

Adults: Refer to official dosing guidelines for specific indications and dosages.

Mechanism of action

Fumarate acts primarily as an intermediate in the TCA cycle, where it is converted to malate by the enzyme fumarase. This process is essential for the continuation of aerobic respiration, facilitating the conversion of carbohydrates, fats, and proteins into energy. Additionally, fumarate can participate in redox reactions, influencing cellular metabolism and signaling pathways.

Pharmacodynamics

Fumarate influences various metabolic pathways, including the urea cycle and glycolysis, by participating in electron transfer processes. Its role in the TCA cycle is vital for ATP production, and its interaction with other metabolic pathways helps regulate energy homeostasis and the balance of nitrogen in the body.

Pharmacokinetics

The pharmacokinetics of fumarate involve its absorption, distribution, metabolism, and excretion. Fumarate is readily absorbed when introduced into the body and is distributed to various tissues where it participates in metabolic processes. The metabolic conversion of fumarate occurs primarily in the mitochondria through the TCA cycle, and its elimination from the body is facilitated by renal pathways.

Pregnancy

There are no established guidelines regarding the use of fumerate during pregnancy. Consult healthcare professionals for individual risk assessment.

Breast-feeding

The safety of fumerate during breastfeeding has not been established. Caution is advised and consultation with healthcare professionals is recommended.

Storage

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

Indications

• Hypomagnesemia
• Prevention and treatment of magnesium deficiency
• Management of certain cardiac arrhythmias
• Adjunctive treatment in severe asthma
• Eclampsia and pre-eclampsia in pregnant women

Dosage

Children: Refer to pediatric dosing guidelines in the BNF for Children or consult a healthcare professional for appropriate dosing.

Adults: Refer to specific guidelines and consult professional resources for appropriate dosing based on the condition and severity.

Mechanism of action

Magnesium exerts its effects primarily through its role as a cofactor for over 300 enzymatic reactions. It facilitates the activity of ATP (adenosine triphosphate), the energy currency of cells, and is crucial for the synthesis of nucleic acids and proteins. Magnesium also helps stabilize cell membranes and is involved in neurotransmission and muscle contraction. Additionally, it modulates calcium levels in the body, influencing vascular tone and muscle function.

Pharmacodynamics

The pharmacodynamics of magnesium are closely linked to its role in enzymatic activities and cellular signaling. It influences neuromuscular transmission and muscle contraction by modulating calcium ion channels and preventing excessive release of neurotransmitters. Magnesium has a calming effect on the nervous system, potentially aiding in the management of anxiety and promoting relaxation. Its vasodilatory properties contribute to the reduction of blood pressure, making it beneficial for cardiovascular health.

Pharmacokinetics

Magnesium is absorbed primarily in the intestines, and its bioavailability can be affected by dietary factors and the presence of other minerals. Once absorbed, magnesium is distributed throughout the body, with significant concentrations in the bones, muscles, and soft tissues. The kidneys play a key role in regulating magnesium levels, excreting excess amounts to maintain homeostasis. The half-life of magnesium in the body varies depending on the form and route of administration but generally ranges from several hours to a few days.

Adverse effects

• Diarrhea
• Nausea
• Abdominal cramping
• Hypotension
• Drowsiness

Interactions

• May interact with certain antibiotics, reducing their effectiveness
• May enhance the effects of calcium channel blockers
• May interfere with the absorption of some medications when taken simultaneously

Precautions

• Use with caution in patients with renal impairment
• Monitor electrolyte levels in patients receiving large doses
• Caution in patients with heart block or cardiac arrhythmias

Pregnancy

Magnesium is generally considered safe during pregnancy but should be used under medical supervision.

Breast-feeding

Magnesium is excreted in breast milk, typically considered safe for breastfeeding mothers.

Storage

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

Formulations

• Oral tablets
• Powder for oral solution
• Intravenous solution

Indications

• Hypomagnesemia
• Magnesium deficiency
• Cardiac arrhythmias
• Eclampsia
• Asthma exacerbations
• Migraine prophylaxis

Dosage

Children: Refer to the BNF for Children for pediatric dosing recommendations.

Adults: Refer to clinical guidelines or specific product information for adult dosing.

Mechanism of action

Magnesium acts as a cofactor for over 300 enzymatic reactions in the body. It is essential for ATP production, the synthesis of nucleic acids, and the regulation of calcium homeostasis. By modulating calcium channels and neurotransmitter release, magnesium influences neuromuscular transmission and muscle contraction. It also plays a role in stabilizing cellular membranes and protecting against oxidative stress.

Pharmacodynamics

Magnesium's pharmacodynamics involve its effects on various physiological processes, particularly in the cardiovascular and neuromuscular systems. It helps to maintain normal muscle and nerve function and influences cardiac rhythm. Magnesium is known to inhibit excessive calcium influx into cells, thus contributing to vasodilation and lowering blood pressure. It also has a calming effect on the nervous system, which can help alleviate anxiety and promote relaxation.

Pharmacokinetics

Magnesium is absorbed primarily in the small intestine, with the efficiency of absorption being influenced by dietary factors and the presence of other minerals. The body regulates magnesium levels through renal excretion and intestinal absorption. The half-life of magnesium varies depending on the route of administration, with intravenous administration leading to quicker distribution and elimination. The majority of magnesium is stored in the bones, muscles, and soft tissues, with only a small fraction present in the extracellular fluid.

Contra-indications

• Severe renal impairment
• Myasthenia gravis
• Hypocalcemia
• Hypophosphatemia

Adverse effects

• Diarrhea
• Nausea
• Vomiting
• Abdominal cramping
• Hypotension
• Bradypnea
• Muscle weakness

Interactions

• Antibiotics (e.g., tetracyclines, fluoroquinolones) - may bind and reduce their absorption
• Calcium supplements - may compete for absorption
• Diuretics (especially loop diuretics) - can increase the risk of magnesium deficiency
• ACE inhibitors - may enhance the hypotensive effect
• Neuromuscular blocking agents - may potentiate their effects

Precautions

• Use with caution in patients with renal impairment
• Monitor electrolytes in patients with gastrointestinal losses
• Avoid in patients with heart block
• Caution in elderly patients due to potential for electrolyte imbalance

Pregnancy

Magnesium is generally considered safe during pregnancy and is often recommended for certain conditions, such as preeclampsia.

Breast-feeding

Magnesium is excreted in breast milk but is generally considered safe for use during breastfeeding.

Storage

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

Formulations

• Oral tablets
• Oral solution
• Intravenous injection
• Intramuscular injection

Mechanism of action

Oxides do not have a single mechanism of action as they are a broad category of compounds. However, in general, metal oxides can exhibit catalytic properties, while non-metal oxides may participate in biochemical reactions by forming acids or bases upon dissolution in water.

Pharmacodynamics

The pharmacodynamics of oxides depend on the specific type of oxide and its interaction with biological systems. For instance, metal oxides may have antimicrobial properties, while certain non-metal oxides can influence metabolic pathways through their acid-base chemistry. The effects vary widely, necessitating specific studies for each oxide's role in therapeutic contexts.

Pharmacokinetics

The pharmacokinetics of oxides are also variable. Many metal oxides are poorly soluble and thus have limited absorption when ingested. Non-metal oxides, such as carbon dioxide, can be readily absorbed and utilized in metabolic processes. The distribution, metabolism, and excretion of oxides depend on their chemical form and the biological system in which they are involved.

Pregnancy

Not applicable as oxide is not a drug but a class of chemical compounds.

Breast-feeding

Not applicable as oxide is not a drug but a class of chemical compounds.

Storage

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

Indications

• Vitamin deficiency syndromes (e.g., scurvy for vitamin C deficiency, rickets for vitamin D deficiency)
• Support for immune function
• Antioxidant support
• Bone health maintenance
• Vision health
• Energy metabolism support

Dosage

Children: Refer to the BNF for Children for specific vitamin dosing guidelines, which depend on age and nutritional requirements.

Adults: Refer to specific vitamin guidelines as dosage varies significantly depending on the type of vitamin and individual needs.

Mechanism of action

Vitamins function primarily as coenzymes or precursors for coenzymes in enzymatic reactions. For instance, B vitamins are involved in energy metabolism, while vitamins A, C, D, E, and K support various physiological functions including vision, antioxidant activity, calcium regulation, and blood clotting. Each vitamin has a unique mechanism of action based on its structure and role in the body.

Pharmacodynamics

Vitamins exert their effects at the cellular level, influencing metabolic pathways, gene expression, and immune responses. For example, vitamin D regulates calcium and phosphate homeostasis, while vitamin A is crucial for vision and immune function. Deficiencies in vitamins can lead to a range of disorders, highlighting their importance in maintaining health.

Pharmacokinetics

The pharmacokinetics of vitamins vary widely. Fat-soluble vitamins (A, D, E, and K) are stored in liver and adipose tissues and can be released into circulation as needed. Water-soluble vitamins (B-complex and C) are not stored and must be consumed regularly, with excess amounts excreted in urine. Absorption rates, half-lives, and distribution can also differ based on the specific vitamin and individual metabolic factors.

Interactions

• tretinoin+vitamin: Severe (increases risk of vitamin toxicity)
• retinoids+vitamin: Severe (increases risk of vitamin toxicity)
• retinoids+vitamin: Moderate (increases risk of toxicity)
• carbamazepine+vitamin: Unknown (decreases effects)
• cobicistat+vitamin: Unknown (increases exposure)
• vitamin D substances+digoxin: Unknown (increases risk of toxicity)
• idelalisib+vitamin: Unknown (increases exposure)
• clarithromycin+vitamin: Unknown (increases exposure)

Pregnancy

Consult healthcare professional before use. Vitamin supplementation during pregnancy should be carefully managed to avoid hypervitaminosis.

Breast-feeding

Consult healthcare professional before use. Some vitamins can pass into breast milk and may affect the infant.

Storage

Store in a cool, dry place, away from direct sunlight. Ensure it is kept out of reach of children.

Formulations

• {'name': 'Vitamin A', 'form': 'Capsule', 'strength': '10000 IU'}
• {'name': 'Vitamin D', 'form': 'Tablet', 'strength': '1000 IU'}
• {'name': 'Vitamin E', 'form': 'Softgel', 'strength': '400 IU'}

Indications

• Vitamin deficiency disorders
• Scurvy (vitamin C deficiency)
• Rickets (vitamin D deficiency)
• Pernicious anemia (vitamin B12 deficiency)
• Night blindness (vitamin A deficiency)

Dosage

Children: Refer to specific guidelines for individual vitamins, as dosages vary based on age, weight, and clinical condition.

Adults: Refer to specific guidelines for individual vitamins, as dosages vary widely between different types.

Mechanism of action

Vitamins act as coenzymes or precursors for coenzymes in various metabolic pathways. For instance, B vitamins are involved in energy metabolism by facilitating enzymatic reactions that convert carbohydrates, fats, and proteins into energy. Vitamin C acts as an antioxidant and is involved in collagen synthesis, while vitamin D regulates calcium and phosphate metabolism, promoting bone health.

Pharmacodynamics

Vitamins exert their effects by interacting with specific receptors or enzymes, influencing metabolic pathways. For example, vitamin A is crucial for vision and immune function, while vitamin K is essential for blood coagulation. The pharmacodynamic effects vary widely depending on the specific vitamin and its role in the body.

Pharmacokinetics

The absorption, distribution, metabolism, and excretion of vitamins differ based on their solubility. Water-soluble vitamins are typically absorbed in the gastrointestinal tract and excreted via urine, which can lead to rapid depletion if not regularly consumed. Fat-soluble vitamins are absorbed along with dietary fats and can be stored in body tissues, leading to a risk of toxicity if taken in excessive amounts. Metabolism of vitamins often involves conversion to active forms, such as the conversion of provitamin A carotenoids to retinol.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Abdominal cramps
• Fatigue
• Headache

Interactions

• Anticoagulants (e.g., warfarin) may have their effects altered when taken with vitamin K
• Large doses of vitamin E may increase the risk of bleeding when used with anticoagulants
• Certain medications may reduce the absorption of fat-soluble vitamins

Precautions

• Use with caution in patients with liver disease
• Monitor for potential interactions with anticoagulant therapy
• Avoid excessive doses, particularly of fat-soluble vitamins (A, D, E, K) due to risk of toxicity

Pregnancy

Generally considered safe, but high doses should be avoided. Consult a healthcare provider.

Breast-feeding

Generally safe, but consult a healthcare provider for high doses.

Storage

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

Formulations

• Tablets
• Capsules
• Soft gels
• Powders
• Liquid formulations

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

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.