BENDURIC 5MG TABLETS

Indications

• Hypertension
• Oedema in heart failure
• Nephrogenic diabetes insipidus
• Partial pituitary diabetes insipidus
• Management of chronic hypoglycaemia

Dosage

Children: For children aged 1 month to 1 year: 50–100 micrograms/kg daily; for children aged 1 to 11 years: Initially 50–400 micrograms/kg daily; for children aged 12–17 years: Initially 5–10 mg once daily.

Adults: Initially 2.5 mg once daily, adjusted according to response; maximum 10 mg per day.

Mechanism of action

Bendroflumethiazide works by inhibiting sodium reabsorption at the distal convoluted tubule in the kidneys, leading to increased excretion of sodium and water, which decreases blood volume and blood pressure.

Pharmacodynamics

As a thiazide diuretic, Bendroflumethiazide causes a dose-dependent diuresis and reduction in blood pressure. It also has effects on electrolyte balance, particularly reducing potassium levels and increasing calcium reabsorption.

Pharmacokinetics

Bendroflumethiazide is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 1-3 hours after oral administration. It has a half-life of approximately 6-15 hours, and is primarily excreted in urine. Its effects can last for 24 hours or more.

Contra-indications

• Bilateral renovascular disease
• Severe or symptomatic aortic stenosis
• History of idiopathic or hereditary angioedema

Adverse effects

• Agranulocytosis
• Cholestasis
• Hypotension
• Angioedema
• Alopecia
• Blood disorders

Interactions

• Thiazide diuretics may interact with ACE inhibitors
• Increased risk of agranulocytosis in collagen vascular disease

Precautions

• Use with care in patients with hypertrophic cardiomyopathy
• Use with care in patients with a history of angioedema

Pregnancy

Use only if the benefits outweigh the risks; refer to specific guidelines.

Breast-feeding

The amount present in milk is too small to be harmful; large doses may suppress lactation.

Storage

Store below 25°C. Protect from light.

Formulations

• Bendroflumethiazide 2.5 mg tablets
• Oral suspension
• Oral solution

Indications

• Hypertension
• Psychotic disorders (such as schizophrenia)
• Anxiety disorders

Dosage

Children: Refer to established clinical guidelines for specific dosing recommendations.

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

Mechanism of action

Reserpine acts by inhibiting the vesicular monoamine transporter 2 (VMAT2), which is responsible for the packaging of neurotransmitters like norepinephrine, serotonin, and dopamine into vesicles within neurons. By blocking VMAT2, reserpine leads to the depletion of these neurotransmitters, thereby reducing their availability for release into the synaptic cleft.

Pharmacodynamics

The pharmacodynamic effects of reserpine include a reduction in heart rate, decreased cardiac output, and vasodilation, all contributing to its antihypertensive effects. It also has sedative properties due to its action on the central nervous system, which can result in decreased anxiety and agitation in patients with certain mental health conditions.

Pharmacokinetics

Reserpine is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 1 to 2 hours after oral administration. It is extensively metabolized in the liver, primarily by the cytochrome P450 system, with a half-life ranging from 10 to 30 hours. The drug is primarily excreted in the urine. Its effects can persist for several days after discontinuation due to the depletion of neurotransmitter stores.

Contra-indications

• Hypersensitivity to reserpine or any of its components
• History of peptic ulcer disease
• Severe depression or suicidal tendencies
• Asthma or other respiratory conditions due to the risk of bronchospasm
• Pregnancy and lactation unless prescribed

Adverse effects

• Sedation or drowsiness
• Depression or worsening of pre-existing depression
• Bradycardia
• Hypotension
• Gastrointestinal disturbances such as diarrhea or constipation
• Nasal congestion
• Extrapyramidal symptoms including parkinsonism
• Fatigue

Interactions

• Antihypertensive agents may have an additive effect, increasing the risk of hypotension
• Monoamine oxidase inhibitors (MAOIs) can lead to severe hypotension
• CNS depressants may enhance sedative effects
• Sympathomimetics may reduce the antihypertensive effects of reserpine

Precautions

• Use cautiously in patients with a history of depression
• Monitor blood pressure regularly
• Assess for signs of extrapyramidal symptoms
• Use with caution in patients with a history of peptic ulcers or gastrointestinal disorders
• Consider potential for sedation when operating machinery or driving

Pregnancy

Reserpine is not recommended during pregnancy, as it may affect fetal development.

Breast-feeding

Reserpine is excreted in breast milk; caution is advised if used during lactation.

Storage

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

Formulations

• Oral tablets (commonly available in strengths of 0.1 mg and 0.25 mg)

Mechanism of action

As a diuretic, bendroflumethiazide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like bendroflumethiazide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of bendroflumethiazide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. ...BENZOTHIADIAZIDES HAVE DIRECT EFFECT ON RENAL TUBULAR TRANSPORT OF SODIUM & CHLORIDE...INDEPENDENT OF ANY EFFECT ON CARBONIC ANHYDRASE. /THIAZIDE DIURETICS/ NATURE OF CHEM INTERACTION BETWEEN THIAZIDES & SPECIFIC RENAL RECEPTORS RESPONSIBLE FOR CHLORURETIC EFFECT IS NOT KNOWN; NO CRITICAL ENZYMATIC REACTIONS HAVE BEEN IDENTIFIED. /THIAZIDE DIURETICS/ ...MAY DECR EXCRETION OF URIC ACID IN MAN, THUS INCR ITS CONCN IN PLASMA. HYPERURICEMIC EFFECT RESULTS PRIMARILY FROM INHIBITION OF TUBULAR SECRETION OF URATE. ... UNLIKE MOST OTHER NATRIURETIC AGENTS...DECR RENAL EXCRETION OF CALCIUM RELATIVE TO THAT OF SODIUM... /ENHANCE/ EXCRETION OF MAGNESIUM... /THIAZIDE DIURETICS/ THIAZIDES INHIBIT REABSORPTION OF SODIUM &...CHLORIDE IN DISTAL SEGMENT. ... AS CLASS...HAVE IMPORTANT ACTION ON EXCRETION OF POTASSIUM THAT RESULTS FROM INCR SECRETION OF CATION BY DISTAL TUBULE. ... GLOMERULAR FILTRATION RATE MAY BE REDUCED BY THIAZIDES, PARTICULARLY WITH IV ADMIN FOR EXPTL PURPOSES. /THIAZIDE DIURETICS/ For more Mechanism of Action (Complete) data for BENDROFLUMETHIAZIDE (11 total), please visit the HSDB record page.

Pharmacodynamics

Bendroflumethiazide, a thiazide diuretic, removes excess water from the body by increasing how often you urinate (pass water) and also widens the blood vessels which helps to reduce blood pressure. It inhibits Na⁺/Cl^- reabsorption from the distal convoluted tubules in the kidneys. Thiazides also cause loss of potassium and an increase in serum uric acid. Thiazides are often used to treat hypertension, but their hypotensive effects are not necessarily due to their diuretic activity. Thiazides have been shown to prevent hypertension-related morbidity and mortality although the mechanism is not fully understood. Thiazides cause vasodilation by activating calcium-activated potassium channels (large conductance) in vascular smooth muscles and inhibiting various carbonic anhydrases in vascular tissue.