Drug Groups

approved

Description

A thiazide diuretic with actions and uses similar to those of hydrochlorothiazide. (From Martindale, The Extra Pharmacopoeia, 30th ed, p822)

Indication

Used as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy. Also used in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension.

Pharmacology

Hydroflumethiazide is an oral thiazide used to treat hypertension and edema. High blood pressure adds to the workload of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure. High blood pressure may also increase the risk of heart attacks. Like other thiazides, Hydroflumethiazide promotes water loss from the body (diuretics). Thiazides inhibit 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.

Toxicity

Overdoses lead to diuresis, lethargy progressing to coma, with minimal cardiorespiratory depression and with or without significant serum electrolyte changes or dehydration.

Affected Organisms

Biotransformation

Essentially unchanged

Absorption

Hydroflumethiazide is incompletely but fairly rapidly absorbed from the gastrointestinal tract

Half Life

It appears to have a biphasic biological half-life with an estimated alpha-phase of about 2 hours and an estimated beta-phase of about 17 hours

Protein Binding

74%

References

External Links