Remikiren (Ro 42-5892)--an orally active renin inhibitor in essential hypertension. Effects on blood pressure and the renin-angiotensin-aldosterone system.

Remikiren (Ro 42-5892) is a new orally active renin inhibitor with high potency and specificity in vitro. In the present study, the drug was given in a short-term study in patients with essential hypertension, either as monotherapy or with added hydrochlorothiazide. Following a wash-out period of at least 3 weeks and then 8 days of single-blind placebo, 29 patients with essential hypertension were given remikiren 600 mg orally for 8 days. After 4 days of remikiren, hydrochlorothiazide 12.5 mg or 25 mg or placebo was added in double-blind fashion for the last 4 days. There were no significant changes in blood pressure in patients given remikiren alone. In patients given additional hydrochlorothiazide for 4 days, a marked reduction in blood pressure was observed. Remikiren effectively inhibited the plasma renin activity 24 h post-dose, whereas angiotensin II was reduced only during the first hours after drug administration. It is concluded that remikiren is orally effective. Its antihypertensive effect during short-term administration was not significant, but when given with a diuretic, a marked potentiation occurred. Further studies are needed to establish the long-term effects of remikiren alone and in combination therapy.