Bendroflumethiazide Bristol

For the treatment of oedema and hypertension. Bendroflumethiazide Bristol may also be used to suppress lactation.

For oral administration.

Adults:

Oedema

Initially, 5-10 mg in the morning, daily or on alternate days; maintenance dose 5-10 mg one to three times weekly.

Hypertension

The usual dose is 2.5 mg taken in the morning. Higher doses are rarely necessary.

Suppression of lactation

5 mg in the morning and 5 mg at midday for about five days.

Children: Dosage in children may be up to 400 mcg/kg bodyweight initially, reducing to 50-100 mcg/kg bodyweight daily for maintenance.

Elderly: The dosage of thiazide diuretics may need to be reduced in the elderly, particularly when renal function is impaired, because of the possibility of electrolyte imbalance.

Bendroflumethiazide Bristol is contra-indicated in patients with known hypersensitivity to thiazides; refractory hypokalaemia, hyponatraemia, hypercalcaemia; severe renal and hepatic impairment; symptomatic hyperuricaemia and Addison's disease.

Bendroflumethiazide should be used with caution in patients with mild to moderate hepatic or renal impairment (avoid if severe). Renal function should be continuously monitored during thiazide therapy. Thiazide diuretics may exacerbate or activate systemic lupus erythematosus in susceptible patients.

All thiazide diuretics can produce a degree of electrolyte imbalance, especially in patients with renal or hepatic impairment or when dosage is high or prolonged. Serum electrolytes should be checked for abnormalities, particularly hypokalaemia, and the latter corrected by the addition of a potassium supplement to the regimen. Aggravates diabetes and gout; increased risk of hypomagnesaemia in alcoholic cirrhosis.

Regular ongoing monitoring and blood tests are to be performed in elderly patients and patients who are on long term treatment with bendroflumethiazide.

This product contains lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malsorption should not take this medicine.

No adverse effects known.

All thiazide diuretics can produce a degree of electrolyte imbalance, e.g. hypokalaemia.

Thiazide diuretics may raise the serum uric acid levels with subsequent exacerbation of gout in susceptible subjects.

Thiazide diuretics sometimes lower carbohydrate tolerance and the insulin dosage of the diabetic patient may require adjustment. Care is necessary when bendroflumethiazide is administered to those with a known predisposition to diabetes.

Postural hypotension, mild gastro-intestinal effects and diarrhoea; hypokalaemia, hypomagnesaemia, hyponatraemia, hypercalcaemia, hypochloraemic alkalosis, hyperuricaemia, gout, hyperglycaemia, and altered plasma lipid concentration.

Less commonly, rashes, photosensitivity; blood disorders (including neutropenia and thrombocytopenia - when given in late pregnancy neonatal thrombocytopenia has been reported); pancreatitis, intrahepatic cholestasis, and hypersensitivity reactions (including pneumonitis, pulmonary oedema, severe skin reactions) also reported.

Rarely, blood dyscrasias, including agranulocytosis, aplastic anaemia, thrombocytopenia and leucopenia, and pancreatitis have been reported with long term therapy. Skin rashes and impotence (reversible on withdrawal of treatment) have occasionally been reported.

Symptoms of overdosage include anorexia, nausea, vomiting, diarrhoea, diuresis, dehydration, hypotension, dizziness, weakness, muscle cramps, paraesthesia, tetany, gastrointestinal bleeding, hyponatraemia, hypo- or hyperglycaemia, hypokalaemia and metabolic alkalosis. Initial treatment consists of either emesis or gastric lavage, if appropriate. Otherwise treatment should be symptomatic and supportive including the correction of fluid and electrolyte imbalance.

Blood pressure should also be monitored.

There is no specific antidote.

Bendroflumethiazide is a thiazide diuretic which reduces the absorption of electrolytes from the renal tubules, thereby increasing the excretion of sodium and chloride ions, and consequently of water. The excretion of other electrolytes, notably potassium and magnesium, is also increased. The excretion of calcium is reduced. Thiazides also reduce carbonic anhydrase activity so that bicarbonate excretion is increased, but this effect is generally small and does not appreciably alter the acid base balance or the pH of the urine. Thiazides also have a hypotensive effect, due to a reduction in peripheral resistance and enhance the effects of other antihypertensive agents.

Bendroflumethiazide is completely absorbed from the gastrointestinal tract and it is fairly extensively metabolised. About 30% is excreted unchanged in the urine. The onset of diuretic action of the thiazides following oral administration occurs within two hours and the peak effect between three and six hours after administration. The duration of the diuretic action of bendroflumethiazide is between 18 and 24 hours. The onset of the hypotensive action is generally three or four days.

Not applicable

Not applicable.

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