PHARMAPRESS CO Tablet Ref.[51196] Active ingredients: Enalapril Hydrochlorothiazide

Enalapril maleate

Absorption

Enalapril acts as a pro-medicine of the diacid enalaprilat, its active form, which is poorly absorbed orally. About 60% of an oral dose of enalapril is absorbed from the gastrointestinal tract and peak plasma concentrations occur within about 1 hour.

The absorption of oral enalapril maleate is not influenced by the presence of food in the gastrointestinal tract.

Distribution

Steady state serum concentrations of enalaprilat are achieved by the fourth day of administration of enalapril maleate in patients with normal renal function.

Metabolism

Enalapril is extensively hydrolysed in the liver to the active metabolite enalaprilat; peak plasma concentrations of enalaprilat occur 3 to 4 hours after an oral dose of enalapril.

Elimination

After an oral dose, enalapril is excreted in the urine and in faeces, as enalaprilat and unchanged enalapril, with the urinary route predominating. The elimination of enalaprilat is multiphasic but the effective half-life for accumulation after multiple doses of enalapril is reported to be about 11 hours in patients with normal renal function.

Hydrochlorothiazide

Hydrochlorothiazide is absorbed from the gastrointestinal tract. It is reported to have a bioavailability of about 65% to 70%.

Distribution

Hydrochlorothiazide appears to be preferentially bound to red blood cells.

Metabolism

Hydrochlorothiazide is excreted unchanged.

Elimination

Hydrochlorothiazide has been estimated to have a plasma half-life of between about 5 and 15 hours. Hydrochlorothiazide is eliminated rapidly by the kidney with at least 61% of the oral dose eliminated unchanged within 24 hours in the urine.