Enalapril maleate is a prodrug which when administered orally is hydrolysed to release the active converting enzyme inhibitor enalaprilat. Enalapril maleate is 60% absorbed and 40% bioavailable as enalaprilat. Both compounds undergo renal excretion without further metabolism. The functional half‐life for accumulation of enalaprilat is 11 h, and this is increased in the presence of a reduction in renal function. Inhibition of converting enzyme inhibition is associated with reductions in plasma angiotensin II and plasma aldosterone, and with increases in plasma renin activity and plasma angiotensin I. Acute and chronic effects have been reviewed. When given with hydrochlorothiazide, enalapril attenuates the secondary aldosteronism and ameliorates the hypokalaemia from diuretics. Both acutely and chronically in patients with essential hypertension, enalapril reduced blood pressure with a rather flat dose‐response curve. No evidence of a triphasic response such as seen with captopril has been demonstrated with enalapril, and blood pressure returns smoothly to pretreatment levels when the drug is abruptly discontinued. Once‐ or twice‐daily dosing gives similar results. The antihypertensive effects of enalapril are potentiated by hydrochlorothiazide. Haemodynamically, blood pressure reduction is associated with a reduced peripheral vascular resistance and an increase in cardiac output and stroke volume with little change in heart rate. Renal vascular resistance decreases, and renal blood flow may increase without an increase in glomerular filtration in patients with normal renal function. In patients with essential hypertension and glomerular filtration rates below 80 ml/min/m2, both renal blood flow and glomerular filtration rates may increase.

Seed of Adonis microcarpa (pheasant's eye) fed at 5.6 g/kg of the diet induced virtually total feed refusal within 3 d in growing and finishing pigs. It also caused vomiting, rapid and shallow breathing and death in a minority. These effects were probably caused by cardiac glycosides whose structure and effects closely resemble those of digoxin. Feed intake and growth recovered within 2 weeks of removal of the seed.

Racemic indacrinone is a potent loop diuretic with transient uricosuric properties in certain nonhuman primates and in man. After chronic treatment, hyperuricemia develops presumably because of enhanced proximal tubular urate reabsorption secondary to extracellular fluid volume contraction. The natriuretic and uricosuric activities are associated with both enantiomers, but the (-)-enantiomer is significantly more potent as a natriuretic agent than the (+). Acutely, in Cebus monkeys, both enantiomers appear to have similar uricosuric activity. The difference in the natriuretic potency between the two enantiomers provides the possibility of altering the enantiomer ratio from its naturally occurring 1:1 ratio to another combination which would enhance the uricosuric action [more (+) relative to (-)] while preserving the potent natriuretic action of the (-). In healthy volunteers, a 1:4 ratio [(-):(+)] was isouricemic after 7 days of treatment and a 1:8 mixture lowered mean serum urate by 13%. Presumably, the desired ratio of (-):(+) will be in the range 1:4-1:9. Further enhancement of the diuretic profile of this compound may be obtained by adding sufficient amiloride to produce isokalemia.