Atacand

Indications

• Hypertension
• Heart failure
• Left ventricular dysfunction post-myocardial infarction

Dosage

Children: For children aged 1 to 17 years, the dose is based on body weight. The recommended starting dose is 0.05 to 0.1 mg/kg once daily, with a maximum dose of 0.4 mg/kg or 32 mg, whichever is lower.

Adults: The typical adult starting dose for hypertension is 8 mg once daily, which may be increased to a maximum of 32 mg once daily based on blood pressure response.

Mechanism of action

Candesartan selectively antagonizes the type I angiotensin II receptor (AT1), preventing angiotensin II from exerting its vasoconstrictive and aldosterone-secreting effects. This inhibition allows for vasodilation and decreased aldosterone release, promoting sodium excretion and lowering blood pressure. Candesartan does not affect the degradation of bradykinin, thus minimizing the common side effects associated with ACE inhibitors, such as cough and angioedema.

Pharmacodynamics

Candesartan effectively reduces systemic vascular resistance and lowers blood pressure, which can lead to a decrease in myocardial oxygen demand. Its long duration of action allows for once-daily dosing, and it has shown efficacy in both monotherapy and in combination with other antihypertensive agents. It also demonstrates cardioprotective effects, making it beneficial in the management of heart failure.

Pharmacokinetics

Candesartan is well-absorbed following oral administration, with peak plasma concentrations occurring approximately 1 to 3 hours after dosing. It has a bioavailability of around 15% due to extensive first-pass metabolism. Candesartan is primarily excreted via the kidneys, with a half-life of about 9 hours. The presence of food does not significantly affect its absorption.

Contra-indications

• Hypersensitivity to candesartan or any of its excipients
• Severe hepatic impairment
• Pregnancy

Adverse effects

• Dizziness
• Fatigue
• Hypotension
• Hyperkalemia
• Renal impairment
• Angioedema

Interactions

• Other antihypertensive agents may increase the hypotensive effect
• Potassium-sparing diuretics or potassium supplements may increase the risk of hyperkalemia
• Non-steroidal anti-inflammatory drugs (NSAIDs) may reduce the antihypertensive effect and increase the risk of renal impairment

Precautions

• Caution in patients with renal artery stenosis
• Monitor renal function, especially in patients with pre-existing renal impairment
• Caution in patients with aortic stenosis or hypertrophic cardiomyopathy
• Use with caution in patients with a history of angioedema

Pregnancy

Candesartan is contraindicated in pregnancy due to potential harm to the fetus, particularly in the second and third trimesters.

Breast-feeding

Candesartan is excreted in breast milk, and caution should be exercised when administering to breastfeeding women.

Storage

Store below 25°C in a dry place, protect from light.

Formulations

• Tablets: 4 mg, 8 mg, 16 mg, 32 mg

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

• Hypertension
• Heart failure
• Certain cardiovascular conditions

Dosage

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

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

Cilexetil is converted to its active form, which blocks the action of angiotensin II, a potent vasoconstrictor involved in blood pressure regulation. By inhibiting the angiotensin II receptor, cilexetil promotes vasodilation and decreases peripheral vascular resistance, leading to a reduction in blood pressure.

Pharmacodynamics

Cilexetil's antihypertensive effects are realized through its antagonistic action on the angiotensin II receptors, which results in decreased levels of aldosterone, inhibition of vasoconstriction, and reduced secretion of antidiuretic hormone. The overall pharmacodynamic profile contributes to improved cardiac output and reduced workload on the heart.

Pharmacokinetics

Cilexetil is well-absorbed following oral administration and undergoes extensive first-pass metabolism to its active metabolite. The pharmacokinetic profile indicates a moderate half-life, allowing for once-daily dosing. The distribution of cilexetil is extensive, with high protein binding rates, primarily to serum albumin. Metabolism occurs mainly in the liver, and renal excretion is the primary route for elimination of the drug and its metabolites.

Pregnancy

There is limited data on the use of cilexetil in pregnancy. Caution is advised.

Breast-feeding

It is not known whether cilexetil is excreted in human milk. Caution is recommended.

Storage

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

Indications

• Anxiety disorders
• Nausea and vomiting
• Allergic conditions
• Preoperative sedation
• Pruritus

Dosage

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

Adults: Refer to the BNF for specific dosing guidelines based on the indication and patient characteristics.

Mechanism of action

Hydroxyzine works by antagonizing the H1 histamine receptors, leading to a reduction in the effects of histamine in the body. This action helps alleviate symptoms of allergic reactions and promotes sedation. Additionally, it may exert effects on serotonin and adrenergic receptors, which could contribute to its anxiolytic properties. Hydroxyzine is also involved in various metabolic pathways, including selenium metabolism and the degradation of reactive oxygen species.

Pharmacodynamics

The pharmacodynamic effects of hydroxyzine include sedation, anxiolysis, and reduction of allergic symptoms. Its sedative effects can make it useful in managing anxiety and inducing sleep, while its antihistaminic properties help to relieve symptoms such as itching and rashes associated with allergic reactions. The onset of action is typically within 15 to 30 minutes when taken orally, with peak effects occurring within 1 to 2 hours.

Pharmacokinetics

Hydroxyzine is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 2 hours after oral administration. It is extensively metabolized in the liver, with metabolites, including cetirizine, possessing their own therapeutic effects. Hydroxyzine has a half-life of approximately 20 hours, allowing for once or twice daily dosing. It is primarily excreted in the urine, with less than 1% of the unchanged drug found in urine.

Interactions

• hydroxyzine+antiepileptics: Severe (increases risk of overheating and dehydration)
• hydroxyzine+zonisamide: Severe (increases risk of overheating and dehydration)
• hydroxychloroquine+penicillamine: Severe (increases risk of haematological toxicity)
• hydroxychloroquine+agalsidase alfa: Unknown (decreases effects)
• hydroxychloroquine+agalsidase beta: Unknown (decreases exposure)
• hydroxychloroquine+oral cholera vaccine: Unknown (decreases efficacy)
• live vaccines+hydroxy carbamide: Unknown (increases risk of generalised infection (possibly life-threatening))
• lanthanum+hydroxychloroquine: Unknown (decreases absorption)
• macrolides+hydroxychloroquine: Unknown (increases risk of serious cardiovascular adverse effects)
• hydroxychloroquine+remdesivir: Unknown (decreases effects)

Pregnancy

Safety in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Use with caution. Hydroxychloroquine is excreted in breast milk, and effects on the infant are unknown.

Storage

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

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

• Hypovolemia
• Fluid resuscitation during surgical procedures
• Shock
• Burns

Dosage

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

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

Mechanism of action

Polygeline works by increasing oncotic pressure within the vascular compartment, which draws fluid into the intravascular space from the interstitial compartments. This helps to expand blood volume and improve circulation, particularly in cases of hypovolemia due to trauma, surgery, or other causes.

Pharmacodynamics

Polygeline exhibits a rapid onset of action, with effects on plasma volume restoration observable within minutes of administration. Its colloidal properties allow it to maintain plasma volume for a sustained period, although the duration of action may vary depending on the patient's condition and the volume of fluid administered. The safety profile of polygeline is generally favorable, with minimal risk of allergic reactions or anaphylaxis compared to other colloids.

Pharmacokinetics

Polygeline is administered intravenously, where it is rapidly distributed into the vascular space. The elimination half-life is variable, influenced by factors such as the patient's renal function and fluid balance. Polygeline is metabolized in the liver and excreted primarily through the kidneys. Its colloidal nature means that it does not distribute into the interstitial space as readily as crystalloids, allowing it to maintain intravascular volume longer.

Contra-indications

• Hypersensitivity to polygeline or any of its components
• Severe dehydration
• Active bleeding disorders

Adverse effects

• Allergic reactions including rash and itching
• Headache
• Nausea and vomiting
• Hypotension
• Tachycardia
• Fluid overload

Interactions

• Caution when used with anticoagulants, as it may enhance the risk of bleeding
• May interact with diuretics, leading to altered fluid balance

Precautions

• Use with caution in patients with renal impairment
• Monitor fluid balance in patients with heart failure or hypertension
• Assess for potential allergic reactions prior to administration

Pregnancy

There are limited data on the use of polygeline during pregnancy. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether polygeline is excreted in human milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Formulations

• Intravenous solution

Indications

• Hyperthyroidism
• Graves' disease
• Thyroid storm

Dosage

Children: Refer to the BNF

Adults: The usual initial dose of propylthiouracil in adults is 300 mg per day, divided into 3 doses. The maintenance dose is typically 100-150 mg per day, adjusted based on thyroid function tests.

Mechanism of action

Propylthiouracil acts by inhibiting the enzyme thyroid peroxidase, which is involved in the iodination of tyrosine residues in thyroglobulin, a precursor of thyroid hormones. By blocking this enzyme, PTU reduces the production of thyroxine (T4) and triiodothyronine (T3), leading to decreased thyroid hormone levels in circulation. Additionally, PTU inhibits the conversion of T4 to T3 in peripheral tissues, further contributing to its antithyroid effects.

Pharmacodynamics

The pharmacodynamic effects of propylthiouracil are primarily centered around its ability to lower thyroid hormone levels, which helps alleviate symptoms of hyperthyroidism such as increased heart rate, weight loss, and anxiety. The onset of action can vary, but therapeutic effects may be observed within several weeks of initiation. Monitoring thyroid function tests is essential to assess the efficacy and adjust dosing as needed.

Pharmacokinetics

Propylthiouracil is well absorbed from the gastrointestinal tract, though its bioavailability can be affected by factors such as food intake. The drug is extensively metabolized in the liver, and its elimination half-life averages around 1-2 hours. Most of the drug is excreted in urine as metabolites. It is important to note that due to its rapid metabolism, multiple daily doses may be required to maintain therapeutic levels.

Interactions

• propylthiouracil+metyrapone: Severe (decreases effects)

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

Mechanism of action

Although these agents /angiotensin II receptor antagonists/ are similar to ACE inhibitors in that they decrease the effects of angiotensin II, rather than decreasing the formation of angiotensin II, drugs antagonize angiotensin II at the type I angiotensin receptor. This allows the drugs to inhibit the vasoconstrictive and aldosterone promoting effects of angiotensin II without interfering with bradykinin degradation, significantly reducing the adverse effects of cough and angioedema seen with ACE inhibitor therapy. ... /Angiotensin II receptor antagonists/ Angiotensin II is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II). Angiotensin II is the principal pressor agent of the renin-angiotensin system, with effects that include vasoconstriction, stimulation of synthesis and release of aldosterone, cardiac stimulation, and renal reabsorption of sodium. Candesartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in many tissues, such as vascular smooth muscle and the adrenal gland. Its action is, therefore, independent of the pathways for angiotensin II synthesis. There is also an AT2 receptor found in many tissues, but AT2 is not known to be associated with cardiovascular homeostasis. Candesartan has much greater affinity (>10,000-fold) for the ATI receptor than for the AT2 receptor. Blockade of the renin-angiotensin system with ACE inhibitors, which inhibit the biosynthesis of angiotensin II from angiotensin I, is widely used in the treatment of hypertension. ACE inhibitors also inhibit the degradation of bradykinin, a reaction also catalyzed by ACE. Because candesartan does not inhibit ACE (kininase II), it does not affect the response to bradykinin. Whether this difference has clinical relevance is not yet known. Candesartan does not bind to or block other hormone receptors or ion channels known to be important in cardiovascular regulation. Blockade of the angiotensin II receptor inhibits the negative regulatory feedback of angiotensin II on renin secretion, but the resulting increased plasma renin activity and angiotensin II circulating levels do not overcome the effect of candesartan on blood pressure.