indication

For the treatment of high blood pressure and management of edema related to heart failure.

pharmacology

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.

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.

absorption

Absorbed relatively rapidly after oral administration

half life

8.5 hours

drug interactions

Deslanoside: Possible electrolyte variations and arrhythmias

Diazoxide: Significant hyperglycemic effect

Digitoxin: Possible electrolyte variations and arrhythmias

Digoxin: Possible electrolyte variations and arrhythmias

Dofetilide: Increased risk of cardiotoxicity and arrhythmias

Lithium: The thiazide diuretic, bendroflumethiazide, may increase serum levels of lithium.

Trandolapril: The thiazide diuretic, Bendroflumethiazide, may increase the hypotensive effect of Trandolapril. Bendroflumethiazide may also increase the nephrotoxicity of Trandolapril. Monitor for postural hypotension at initiation of concomitant therapy and renal dysfunction during chronic therapy.

Treprostinil: Additive hypotensive effect. Monitor antihypertensive therapy during concomitant use.