THYROXIN 100

Indications

• Primary hypothyroidism
• Subclinical hypothyroidism
• Secondary hypothyroidism due to pituitary disease
• Congenital hypothyroidism
• Thyroid hormone replacement in patients with thyroidectomy
• Management of myxedema coma (in emergency settings)
• Hypothyroidism in patients with cardiac disease (with caution)

Dosage

Adults: Initially 1.6 micrograms/kg once daily, adjusted according to response, round dose to the nearest 25 micrograms. For the elderly, initially 25–50 micrograms once daily, adjusted in steps of 25 micrograms every 4 weeks

Mechanism of action

Levothyroxine sodium acts as a replacement for endogenous thyroxine, binding to thyroid hormone receptors in the nucleus of cells. This initiates the transcription of genes that regulate various metabolic processes, including protein synthesis, carbohydrate metabolism, and lipid metabolism. The increase in metabolic rate enhances the overall physiological processes in the body, promoting normal growth and development.

Pharmacodynamics

The pharmacodynamic effects of levothyroxine sodium include increased basal metabolic rate, enhancement of gluconeogenesis and glycogenolysis, and promotion of protein synthesis. It also plays a vital role in the development of the central nervous system and regulates the metabolism of carbohydrates and fats. The effects are dose-dependent, with higher doses leading to more pronounced effects on metabolism.

Pharmacokinetics

Levothyroxine sodium is well-absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 2 to 4 hours after oral administration. It has a half-life of approximately 6 to 7 days, allowing for once-daily dosing. The drug is extensively bound to plasma proteins, primarily thyroxine-binding globulin, and is metabolized predominantly in the liver. Renal impairment may prolong its half-life, necessitating dose adjustments in patients with compromised renal function.

Adverse effects

• Hyperthyroidism
• Allergic reactions
• Cardiac arrhythmias
• Osteoporosis
• Weight loss
• Nervousness
• Insomnia
• Menstrual irregularities
• Heat intolerance
• Tremors

Interactions

• Anticoagulants (e.g., warfarin) - increased effect
• Antidiabetic agents - possible alteration in blood glucose control
• Cholestyramine - may reduce levothyroxine absorption
• Calcium and iron supplements - may interfere with absorption
• Certain antidepressants (e.g., sertraline) - may require dose adjustment
• Estrogens - may increase levothyroxine requirements

Precautions

• Cardiac disease - need for careful dose adjustment
• Adrenal insufficiency - should be treated before starting levothyroxine
• Monitoring of thyroid levels is essential to avoid over-treatment
• Caution in patients with impaired hepatic or renal function

Pregnancy

Levothyroxine is considered safe during pregnancy, but dose adjustments may be required to maintain normal thyroid function.

Breast-feeding

Levothyroxine is excreted in breast milk in small amounts, but it is generally considered safe for use during breastfeeding.

Storage

Store in a cool, dry place away from light. Do not store above 25 degrees Celsius.

Formulations

• Tablets (various strengths)
• Oral solution

Indications

• Constipation
• Dietary fiber supplementation
• Irritable bowel syndrome
• Diverticular disease
• Weight management

Dosage

Children: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Adults: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Mechanism of action

Cellulose acts primarily as a bulk-forming laxative. It absorbs water in the intestines, which increases stool bulk and stimulates peristalsis, thus facilitating bowel movements. Additionally, cellulose is not digestible by human enzymes, leading to fermentation by gut bacteria, which may enhance gut health and alter gut microbiota composition.

Pharmacodynamics

Cellulose increases stool weight and frequency of bowel movements. It works by retaining water in the intestines, leading to softer stools and improved passage through the gastrointestinal tract. The bulking effect of cellulose can help alleviate constipation and promote overall digestive health. It may also play a role in cholesterol reduction and glycemic control through its effects on digestion and absorption of nutrients.

Pharmacokinetics

Cellulose is not absorbed into the bloodstream due to its indigestible nature. Instead, it passes through the gastrointestinal tract, where it adds bulk to the stool. Its fermentation by colonic bacteria produces short-chain fatty acids, which may have beneficial effects on colon health. The onset of action for cellulose as a laxative can vary but is generally within 24 to 72 hours after ingestion.

Adverse effects

• Bloating
• Flatulence
• Diarrhea
• Abdominal discomfort

Precautions

• Use with caution in patients with a history of gastrointestinal disorders.
• Monitor for potential allergic reactions in sensitive individuals.

Pregnancy

Cellulose is generally considered safe during pregnancy as it is a non-toxic, indigestible fiber.

Breast-feeding

Cellulose is also considered safe during breastfeeding; it is excreted in breast milk in negligible amounts.

Storage

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

Formulations

• Powder
• Capsules
• Tablets
• Granules

Indications

• Hypovolemic shock
• Severe burns
• Postoperative fluid replacement
• Sepsis
• Trauma management

Dosage

Children: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Adults: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Mechanism of action

Colloidal solutions work by maintaining oncotic pressure in the blood, thus helping to retain fluid within the vascular system. This is primarily due to the large molecular weight of the colloidal particles, which cannot easily pass through capillary walls. The presence of colloids in the blood helps to draw water into the circulation, increasing blood volume and improving tissue perfusion.

Pharmacodynamics

The pharmacodynamics of colloidal solutions are centered on their ability to exert osmotic pressure, which helps maintain blood volume and pressure. This effect is particularly important in conditions such as hypovolemia and shock, where fluid replacement is necessary to restore hemodynamic stability. The efficacy of colloidal solutions can vary depending on the type of colloid used, as well as the underlying clinical condition being treated.

Pharmacokinetics

Colloidal solutions are typically administered intravenously and their pharmacokinetics can vary based on the specific formulation. Generally, colloids are distributed throughout the vascular compartment and have a longer duration of action compared to crystalloids, as they remain in circulation longer. The elimination of colloids is primarily through the reticuloendothelial system, where they are metabolized or eliminated by the liver and spleen. Factors such as particle size and composition can influence their distribution and clearance.

Adverse effects

• Allergic reactions
• Injection site reactions
• Nausea
• Vomiting
• Headache
• Fever

Precautions

• Use with caution in patients with known allergies to any component of the formulation
• Monitor for signs of hypersensitivity during administration
• Consider volume overload in patients with cardiac or renal impairment

Pregnancy

The safety of colloidal solutions during pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether colloidal solutions are excreted in human milk. Caution should be exercised when administering to breastfeeding mothers.

Storage

Store at room temperature, protect from light, and do not freeze. Keep out of reach of children.

Formulations

• Colloidal silver
• Colloidal gold
• Colloidal iron
• Other metal colloids

Mechanism of action

The precise mechanism of action is not well-documented in the provided resources. However, compounds with similar molecular structures often interact with biological pathways through modulation of neurotransmitter systems or receptor activity.

Pharmacodynamics

Pharmacodynamics for compounds like Colour typically involve interactions at the cellular level, influencing physiological responses through receptor binding and modulation of signaling pathways. The specific effects and potency would depend on the context of use and formulation.

Pharmacokinetics

Information on the pharmacokinetics of Colour, including absorption, distribution, metabolism, and excretion, is not provided in the available resources. Generally, pharmacokinetic properties will vary significantly based on formulation and route of administration.

Pregnancy

Safety in pregnancy has not been established. Use only if the benefits outweigh the risks.

Breast-feeding

Caution is advised. There are no adequate studies in breastfeeding women.

Storage

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

Indications

• Monitoring respiratory function
• Assessment of metabolic status
• Management of respiratory acidosis
• Management of respiratory alkalosis

Dosage

Children: Dosing for interventions related to carbon dioxide levels in pediatric patients should be guided by clinical protocols and the BNF for Children.

Adults: Dosing for interventions related to carbon dioxide levels is typically based on clinical assessment and individual patient needs. Refer to clinical guidelines for specific scenarios.

Mechanism of action

Carbon dioxide acts primarily as a signaling molecule in the body, influencing respiratory drive and blood pH. It is produced during cellular respiration and is a critical component of the bicarbonate buffering system, which helps maintain acid-base homeostasis. Elevated levels of CO2 in the blood stimulate ventilation in the lungs, increasing the rate of gas exchange and facilitating the removal of excess CO2.

Pharmacodynamics

The pharmacodynamic effects of dioxides, particularly carbon dioxide, are closely related to its concentration in the blood. As CO2 levels increase, it leads to respiratory acidosis, which can stimulate the respiratory centers in the brain to increase ventilation. Conversely, low levels of CO2 can cause respiratory alkalosis, potentially leading to decreased respiratory drive. CO2 also plays a role in vasodilation and can affect blood flow and pressure through its influence on smooth muscle tone.

Pharmacokinetics

Carbon dioxide is produced endogenously during metabolic processes and is transported in the bloodstream primarily in three forms: dissolved in plasma, as bicarbonate ions (HCO3-), and bound to hemoglobin. The half-life of CO2 in the bloodstream is very short due to its rapid exchange with alveolar gas in the lungs. The elimination of CO2 occurs through exhalation, making it a dynamic component of respiratory physiology.

Pregnancy

Data on the effects of dioxide during pregnancy are limited. Caution is advised due to potential risks associated with exposure.

Breast-feeding

Limited data are available regarding the excretion of dioxide in human milk. Caution is recommended.

Storage

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

Dosage

Children: Refer to specific clinical guidelines for dosing in children, as no standard paediatric dosage is specified in the provided resources.

Adults: Refer to specific clinical guidelines for dosing, as no standard adult dosage is specified in the provided resources.

Mechanism of action

Ethylene glycol toxicity results from its metabolism to glycolic acid and other toxic metabolites. Glycolate accumulates in the body and is eliminated more slowly than ethylene glycol itself. The renal excretion of both compounds plays a crucial role in their elimination, accounting for a significant portion of the administered dose.

Pharmacodynamics

The pharmacodynamics of glycolate are closely tied to its role as a metabolite of ethylene glycol. Its accumulation can lead to metabolic acidosis, although minimal clinical effects have been observed at low doses. The relationship between glycolate and ethylene glycol indicates that glycolate may contribute to the overall toxic effects of ethylene glycol ingestion.

Pharmacokinetics

The pharmacokinetics of glycolate indicate that it reaches peak plasma levels between 4-6 hours after the administration of ethylene glycol. The elimination half-life of ethylene glycol is approximately 1.7 hours in rats and 3.4 hours in dogs. Glycolate is predominantly eliminated through renal excretion, with about 5% of the dose being excreted unchanged.

Pregnancy

There is limited data on the safety of glycolate in pregnancy. Caution is advised.

Breast-feeding

Data on the excretion of glycolate in human milk is not available. Caution is advised.

Storage

Store at room temperature, away from light and moisture.

Indications

• Lactose intolerance
• As a filler or excipient in pharmaceutical formulations

Dosage

Children: Refer to the BNF for Children for specific dosing information based on age and clinical context.

Adults: Refer to the BNF for specific dosing information based on clinical context.

Mechanism of action

Lactose is metabolized in the intestine by the enzyme lactase into its constituent monosaccharides, glucose and galactose. In individuals with lactase deficiency, unabsorbed lactose passes into the colon, where it is fermented by bacteria, leading to gas production and osmotic effects that contribute to diarrhea.

Pharmacodynamics

The pharmacodynamics of lactose are primarily related to its effects on gastrointestinal function. In healthy individuals, lactose is effectively broken down into glucose and galactose, which are absorbed and utilized for energy. In individuals with lactose intolerance, the unabsorbed lactose can cause osmotic diarrhea and colonic fermentation, leading to discomfort and symptoms associated with lactose intolerance.

Pharmacokinetics

Lactose is not absorbed in the gastrointestinal tract until it is hydrolyzed into glucose and galactose by lactase. The absorption of glucose and galactose occurs in the small intestine. The half-life is not applicable as lactose is not typically administered as a medication but is rather ingested as a natural component of food. Its metabolism primarily occurs in the intestine.

Adverse effects

• Bloating
• Diarrhea
• Abdominal pain
• Flatulence

Precautions

• Use with caution in patients with lactose intolerance.
• Consider potential for gastrointestinal upset in sensitive individuals.

Pregnancy

Lactose is generally considered safe for use during pregnancy. However, consult a healthcare professional for individual advice.

Breast-feeding

Lactose is safe to use while breastfeeding, as it is a natural sugar present in breast milk.

Storage

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

Formulations

• Powder
• Granules
• Tablets
• Syrup

Mechanism of action

Lake acts by inhibiting specific biological pathways, potentially modulating neurotransmitter activity or influencing enzymatic reactions related to its clinical indications. Detailed mechanisms may include receptor antagonism or agonism, enzyme inhibition, or alteration of ion channel activity, depending on the therapeutic target.

Pharmacodynamics

Lake demonstrates dose-dependent effects on the body, with its pharmacological activity correlating with the concentration of the drug in circulation. The drug may exhibit a range of effects from mild to significant, depending on the condition being treated and the individual patient's response.

Pharmacokinetics

The pharmacokinetic profile of Lake includes absorption, distribution, metabolism, and excretion characteristics that dictate its therapeutic efficacy and safety. The drug is expected to have a specific half-life, volume of distribution, and clearance rate, which may vary based on patient factors such as age, weight, and organ function.

Pregnancy

Use in pregnancy only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Use with caution; it is not known whether this drug is excreted in human milk.

Storage

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

Indications

• Hypothyroidism
• Thyroid hormone replacement therapy
• Goiter (as part of treatment)
• Thyroid cancer (in certain cases)

Dosage

Children: For children, dosing is determined by age and weight, and specific guidance should be referred from the BNF for Children.

Adults: The initial dose for adults varies based on clinical circumstances and should be titrated according to TSH levels. Typically, a starting dose is around 50-100 micrograms daily, adjusted as necessary.

Mechanism of action

Levothyroxine acts as a replacement for the deficient thyroid hormone T4 in conditions like hypothyroidism. It increases metabolic rate by decreasing thyroid-stimulating hormone (TSH) production from the pituitary gland and is converted to triiodothyronine (T3) in peripheral tissues, which has more potent metabolic effects. This hormone regulates numerous biochemical pathways that influence growth, metabolism, and overall energy levels in the body.

Pharmacodynamics

Levothyroxine maintains normal T4 levels in individuals with deficiency, exerting physiological effects similar to endogenous T4. It has a narrow therapeutic index, necessitating careful dose titration to achieve a euthyroid state, typically monitored via TSH levels. Over-treatment can lead to hyperthyroid symptoms, whereas under-treatment can cause symptoms of hypothyroidism. Regular monitoring is essential to avoid adverse effects on growth, cardiac function, and metabolism.

Pharmacokinetics

Levothyroxine is well-absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 2 to 4 hours post-administration. It has a long half-life, allowing for once-daily dosing, and is metabolized in the liver and other tissues, with a significant portion excreted as metabolites in urine. The pharmacokinetics can be affected by various factors including age, weight, gastrointestinal health, and interactions with other medications.

Adverse effects

• Increased heart rate
• Diarrhea
• Tremors
• Hypercalcemia
• Weakness
• Weight loss
• Heat intolerance
• Increased appetite

Interactions

• voxilaprevir with sofosbuvir and velpatasvir: Severe (increases absorption)
• oral antacids: Unknown (decreases absorption)
• apalutamide: Unknown (decreases exposure)
• oral calcium salts: Unknown (decreases absorption)
• ritonavir: Unknown (decreases concentration)
• oral iron: Unknown (decreases absorption)
• sucralfate: Unknown (decreases absorption)

Precautions

• Monitor thyroid-stimulating hormone (TSH) levels regularly to maintain a euthyroid state
• Titration of dose should be done slowly and carefully to avoid over- or under-treatment
• Patients should be monitored for responses to titration to prevent negative effects on growth, cardiovascular function, and metabolism

Pregnancy

Levothyroxine is considered safe during pregnancy; however, dosages may need to be adjusted to maintain normal thyroid hormone levels.

Breast-feeding

Levothyroxine is excreted in breast milk but in amounts that are not expected to harm a nursing infant; monitoring is recommended.

Storage

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

Formulations

• Tablets
• Oral solution

Indications

• Nutritional support
• Source of carbohydrates
• Dietary fiber source
• Animal feed

Dosage

Children: As with adults, there are no specific dosing recommendations for maize for children. It can be introduced into the diet in age-appropriate forms and quantities, keeping in mind the overall dietary balance.

Adults: There are no specific dosing recommendations for maize as it is typically consumed as part of a balanced diet. It can be included in daily meals in various forms such as whole kernels, flour, or as part of dishes.

Mechanism of action

Maize primarily acts as a source of energy due to its high carbohydrate content. The complex carbohydrates in maize are broken down into glucose, which is then utilized by the body for energy production. It also contributes to dietary fiber intake, which can aid in digestive health and regulation of blood sugar levels.

Pharmacodynamics

The consumption of maize influences blood glucose and insulin levels due to its carbohydrate content. It has a relatively low glycemic index when consumed in whole form, which can help in managing blood sugar levels. The dietary fiber present in maize can also promote satiety and aid in weight management.

Pharmacokinetics

The digestion of maize begins in the mouth with salivary amylase breaking down starches into simpler sugars. In the stomach and small intestine, enzymes further break down these carbohydrates. The resultant glucose is absorbed into the bloodstream, where it is transported to cells for energy production. The absorption rate can vary based on the form of maize consumed (e.g., whole kernels versus processed forms).

Pregnancy

Maize is generally considered safe for consumption during pregnancy as it is a staple food and provides essential nutrients.

Breast-feeding

Maize is safe to consume while breastfeeding and can provide important nutrients to both the mother and the infant.

Storage

Store in a cool, dry place, away from moisture and pests. Properly sealed containers can help prolong shelf life.

Formulations

• Whole maize grains
• Maize flour (cornmeal)
• Maize starch
• Maize oil

Indications

• Used as an excipient in tablet formulations
• Used as a bulking agent in capsule formulations
• Used in food products as a thickener or stabilizer

Dosage

Children: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Adults: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Mechanism of action

Microcrystalline cellulose acts as a non-digestible filler that enhances the flow properties of powders during the manufacturing of tablets and capsules. It does not have a direct pharmacological action on the body but ensures that the active ingredients are effectively delivered to the patient.

Pharmacodynamics

As a non-active ingredient, microcrystalline cellulose does not exert pharmacodynamic effects typical of active pharmaceutical ingredients. Its primary role is to provide a stable and consistent matrix for the drug, facilitating the release of the active compound once ingested.

Pharmacokinetics

Microcrystalline cellulose is not absorbed in the gastrointestinal tract; it passes through the digestive system largely unchanged. It adds bulk to the stool, which may aid in promoting regular bowel movements. The substance is excreted in feces, where it contributes to dietary fiber intake.

Pregnancy

Data regarding the use of microcrystalline cellulose during pregnancy is limited. It is advisable to consult with healthcare professionals before use.

Breast-feeding

Microcrystalline cellulose is considered safe during breastfeeding, as it is not absorbed systemically.

Storage

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

Indications

• Antimalarial treatment
• Antibacterial therapy
• Potential use in cancer treatment

Dosage

Children: Refer to the BNF for Children for guidance on paediatric dosing, as it is crucial to adjust the dosage based on the child's weight and age.

Adults: Refer to the BNF for specific indications and dosing information for adults, as dosage can vary based on the condition being treated.

Mechanism of action

Quinoline binds to RNA, DNA, and certain polyribonucleotides in the presence of NADPH and rat liver microsomes. The binding reaction is enhanced by inducers of the microsomal monooxygenase system and is inhibited by carbon monoxide, aniline, 7,8-benzoflavone, metyrapone, or SKF 525A. Quinoline preferentially binds to poly(A), poly(C), poly(G), and poly(X), with negligible binding to poly(U) and poly(I). The reactive intermediate for nucleic acid modification appears to be the 2,3- or 3,4-epoxy derivative of quinoline.

Pharmacodynamics

Quinoline exhibits various pharmacological effects, including antimicrobial and antiparasitic activities. Its ability to bind to nucleic acids suggests a mechanism by which it may interfere with nucleic acid synthesis or function, potentially leading to cell death in susceptible organisms. The interaction with polyribonucleotides can alter RNA processing or function, impacting protein synthesis.

Pharmacokinetics

Information on the pharmacokinetics of quinoline is limited. However, compounds in this class are generally absorbed well when administered orally. They may undergo hepatic metabolism, with the potential for various metabolites being formed, some of which may be active. Excretion is primarily via the kidneys, with a half-life that can vary based on specific derivatives.

Pregnancy

There is limited information on the safety of quinoline during pregnancy. It is recommended to avoid use unless absolutely necessary.

Breast-feeding

It is unknown whether quinoline is excreted in human milk. Caution is advised when administering to breastfeeding mothers.

Storage

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

Indications

• Potential role in bone health
• Support for connective tissue formation
• May aid in mineral metabolism

Dosage

Children: There is no established clinical dosage for silicon in paediatric populations, as it is not classified as an essential nutrient.

Adults: There is no established clinical dosage for silicon in adults, as it is not classified as an essential nutrient.

Mechanism of action

Silicon is believed to enhance the synthesis of glycosaminoglycans and collagen, which are important for the structural integrity of connective tissues. It may also influence the activity of certain enzymes involved in bone mineralization, thus playing a role in maintaining bone density and health.

Pharmacodynamics

The pharmacodynamics of silicon is not fully elucidated; however, it is thought to involve the modulation of bone metabolism and the promotion of connective tissue health. Silicon may have a synergistic effect with other minerals, such as calcium and magnesium, aiding in their utilization and metabolism in the body.

Pharmacokinetics

The pharmacokinetics of silicon is complex, as it is not absorbed through typical gastrointestinal pathways. Instead, silicon is thought to be taken up in the form of silicates and then distributed throughout the body, particularly in connective tissues. The elimination of silicon occurs primarily through renal excretion, with some variations depending on dietary intake and individual metabolism.

Pregnancy

Silicon is generally considered safe during pregnancy, as it is a naturally occurring element in the human body. However, specific recommendations regarding supplementation should be followed based on the advice of a healthcare provider.

Breast-feeding

Silicon is present in breast milk in small amounts. Its safety during breastfeeding is generally regarded as acceptable, although supplementation should be approached with caution and under medical advice.

Storage

Silicon should be stored in a cool, dry place, protected from light and moisture. Follow specific storage recommendations provided by the manufacturer if available.

Indications

• Nutritional supplementation
• Energy source in enteral nutrition
• Excipient in pharmaceutical formulations

Dosage

Children: Refer to specific guidelines or product inserts for dosing information, as it can vary based on the context of use.

Adults: Refer to specific guidelines or product inserts for dosing information, as it can vary based on the context of use.

Mechanism of action

Starch is broken down into glucose units by enzymes such as amylase during digestion. The glucose is then absorbed in the intestines and utilized for energy production in the body's cells. This pathway involves hydrolysis of the glycosidic bonds, converting starch into simpler sugars.

Pharmacodynamics

Starch primarily serves as an energy source. Its digestion and absorption lead to an increase in blood glucose levels, which provides energy for metabolic processes. In this context, it plays a crucial role in maintaining energy homeostasis in the body.

Pharmacokinetics

Starch is not absorbed in its polymeric form; it must first be enzymatically hydrolyzed into simpler sugars such as maltose and glucose. The digestion and absorption of starch occur predominantly in the small intestine, with glucose being readily absorbed into the bloodstream. The rate of absorption can vary depending on the type of starch and its physical form.

Adverse effects

• Allergic reactions
• Gastrointestinal discomfort
• Diarrhea
• Constipation

Precautions

• Use with caution in individuals with known allergies to starch or starch derivatives
• Monitor for gastrointestinal symptoms in patients with a history of digestive disorders

Pregnancy

Starch is generally considered safe for use during pregnancy. However, it should be consumed in moderation as part of a balanced diet.

Breast-feeding

Starch is deemed safe for nursing mothers when used in moderation as part of a balanced diet.

Storage

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

Formulations

• Powder
• Granules
• Tablets
• Suspensions

Pregnancy

No specific data available, consult a healthcare professional.

Breast-feeding

No specific data available, consult a healthcare professional.

Storage

Store in a cool, dry place away from light.

Mechanism of action

Ethylene glycol toxicity results from its metabolism to glycolic acid and other toxic metabolites. The accumulation of glycolate and the elimination kinetics of ethylene glycol and its metabolites are not well understood, so studies with male Sprague-Dawley rats and mixed breed dogs have been carried out. Ethylene glycol was administered by gavage to rats and dogs which were placed in metabolic cages for urine and blood sample collection at timed intervals. The peak plasma level of ethylene glycol occurred at 2 hr after dosing and that of glycolate between 4-6 hr. The rate of ethylene glycol elimination was somewhat faster in rats with a half-life of 1.7 hr compared to 3.4 hr in dogs. The maximum plasma level of glycolate was greater in rats although the pattern of accumulation was similar to that in dogs. Glycolate disappeared from the plasma at the same time as ethylene glycol, suggesting a slower rate of elimination of the metabolite than that of ethylene glycol. Renal excretion of ethylene glycol was an important route for its elimination accounting for 20-30% of the dose. Renal excretion of glycolate represented about 5% of the dose. Ethylene glycol induced an immediate, but short lived diuresis compared to that in control rats. Minimal clinical effects (mild acidosis with no sedation) were noted at these doses of ethylene glycol (1-2 g/kg) in both rats and dogs. The results indicate that the toxicokinetics of ethylene glycol and glycolate were similar in both species. The effect of 0.35 to 0.8 mmol/kg glycolic acid and 1.0 to 4.4 mmol/kg sodium glycolate on cyclopropane-epinephrine induced cardiac arrhythmias was examined using dogs. Doses of 0.35 to 0.5 mmol/kg glycolic acid increased the duration of arrhythmias in the 13 dogs tested, whereas doses >0.5 mmol/kg decreased or totally eliminated the arrhythmias in each of 11 dogs. Depression was observed for many of the dogs at higher doses. Sodium glycolate was much less effective in decreasing the arrhythmias, with 3 mmol/kg being required and its action being transient.

Mechanism of action

Levothyroxine is a synthetically prepared levo-isomer of the thyroid hormone thyroxine (T₄, a tetra-iodinated tyrosine derivative) that acts as a replacement in deficiency syndromes such as hypothyroidism. T₄ is the major hormone secreted from the thyroid gland and is chemically identical to the naturally secreted T₄: it increases metabolic rate, decreases thyroid-stimulating hormone (TSH) production from the anterior lobe of the pituitary gland, and, in peripheral tissues, is converted to T₃. Thyroxine is released from its precursor protein thyroglobulin through proteolysis and secreted into the blood where is it then peripherally deiodinated to form triiodothyronine (T₃) which exerts a broad spectrum of stimulatory effects on cell metabolism. T₄ and T₃ have a relative potency of ~1:4. Thyroid hormone increases the metabolic rate of cells of all tissues in the body. In the fetus and newborn, thyroid hormone is important for the growth and development of all tissues including bones and the brain. In adults, thyroid hormone helps to maintain brain function, food metabolism, and body temperature, among other effects. The symptoms of thyroid deficiency relieved by levothyroxine include slow speech, lack of energy, weight gain, hair loss, dry thick skin and unusual sensitivity to cold. The thyroid hormones have been shown to exert both genomic and non-genomic effects. They exert their genomic effects by diffusing into the cell nucleus and binding to thyroid hormone receptors in DNA regions called thyroid hormone response elements (TREs) near genes. This complex of T₄, T₃, DNA, and other coregulatory proteins causes a conformational change and a resulting shift in transcriptional regulation of nearby genes, synthesis of messenger RNA, and cytoplasmic protein production. For example, in cardiac tissues T₃ has been shown to regulate the genes for α- and β-myosin heavy chains, production of the sarcoplasmic reticulum proteins calcium-activated ATPase (Ca2+-ATPase) and phospholamban, β-adrenergic receptors, guanine-nucleotide regulatory proteins, and adenylyl cyclase types V and VI as well as several plasma-membrane ion transporters, such as Na+/K+–ATPase, Na+/Ca2+ exchanger, and voltage-gated potassium channels, including Kv1.5, Kv4.2, and Kv4.3. As a result, many cardiac functions including heart rate, cardiac output, and systemic vascular resistance are closely linked to thyroid status. The non-genomic actions of the thyroid hormones have been shown to occur through binding to a plasma membrane receptor integrin aVb3 at the Arg-Gly-Asp recognition site. From the cell-surface, T₄ binding to integrin results in down-stream effects including activation of mitogen-activated protein kinase (MAPK; ERK1/2) and causes subsequent effects on cellular/nuclear events including angiogenesis and tumor cell proliferation.

Pharmacodynamics

Oral levothyroxine is a synthetic hormone that exerts the same physiologic effect as endogenous T₄, thereby maintaining normal T₄ levels when a deficiency is present. Levothyroxine has a narrow therapeutic index and is titrated to maintain a euthyroid state with TSH (thyroid stimulating hormone) within a therapeutic range of 0.4–4.0 mIU/L. Over- or under-treatment with levothyroxine may have negative effects on growth and development, cardiovascular function, bone metabolism, reproductive function, cognitive function, emotional state, gastrointestinal function and glucose and lipid metabolism. The dose of levothyroxine should be titrated slowly and carefully and patients should be monitored for their response to titration to avoid these effects. TSH levels should be monitored at least yearly to avoid over-treating with levothyroxine which can result in hyperthyroidism (TSH <0.1mIU/L) and symptoms of increased heart rate, diarrhea, tremor, hypercalcemia, and weakness to name a few. As many cardiac functions including heart rate, cardiac output, and systemic vascular resistance are closely linked to thyroid status, over-treatment with levothyroxine may result in increases in heart rate, cardiac wall thickness, and cardiac contractility and may precipitate angina or arrhythmias, particularly in patients with cardiovascular disease and in elderly patients. In populations with any cardiac concerns, levothyroxine should be initiated at lower doses than those recommended in younger individuals or in patients without cardiac disease. Patients receiving concomitant levothyroxine and sympathomimetic agents should be monitored for signs and symptoms of coronary insufficiency. If cardiac symptoms develop or worsen, reduce the levothyroxine dose or withhold for one week and restart at a lower dose. Increased bone resorption and decreased bone mineral density may occur as a result of levothyroxine over-replacement, particularly in post-menopausal women. The increased bone resorption may be associated with increased serum levels and urinary excretion of calcium and phosphorous, elevations in bone alkaline phosphatase and suppressed serum parathyroid hormone levels. Administer the minimum dose of levothyroxine that achieves the desired clinical and biochemical response to mitigate this risk. Addition of levothyroxine therapy in patients with diabetes mellitus may worsen glycemic control and result in increased antidiabetic agent or insulin requirements. Carefully monitor glycemic control after starting, changing or discontinuing levothyroxine.

Mechanism of action

QUINOLINE BINDS TO RNA, DNA & CERTAIN POLYRIBONUCLEOTIDES IN PRESENCE OF NADPH & RAT LIVER MICROSOMES. BINDING WAS PRONOUNCED WITH HELP OF SOME INDUCERS OF MICROSOMAL MONOOXYGENASE SYSTEM. BINDING REACTION REQUIRED NADPH & WAS INHIBITED BY CARBON MONOXIDE, ANILINE, 7,8-BENZOFLAVONE, METHYRAPONE OR SKF 525A. QUINOLINE BOUND PREFERENTIALLY TO POLY(A), POLY(C), POLY(G) & POLY(X), BUT NEGLIGIBLY TO POLY(U) & POLY(I). MOST OF QUINOLINE RESIDUES OF THE ADDUCTS, REGARDLESS OF KIND OF POLYNUCLEOTIDES USED WERE RELEASED BY ACID OR ALKALI AT 100 °C IN FORM OF 3-HYDROXYQUINOLINE. THE 2,3- OR 3,4-EPOXY DERIVATIVE OF QUINOLINE APPARENTLY IS THE REACTIVE INTERMEDIATE FOR NUCLEIC ACID MODIFICATION.