Medroxalol, a new
antihypertensive agent with alpha- and beta-adrenoreceptor blocking properties in both animals and humans, was administered in a single-blind study for 12 weeks to 29 patients with mild and moderate
hypertension (standing blood pressure: 188-130/130-100 mm Hg). After 4 weeks of placebo administration, treatment with oral
medroxalol was begun. Six weeks later, half the subjects added
hydrochlorothiazide, 12.5 mg twice daily, to
medroxalol for an additional 6 weeks, and the other half added placebo. During the final 4-week period
medroxalol, but not
hydrochlorothiazide, was discontinued and placebo substituted. Oral
medroxalol doses of 100-400 mg twice daily reduced standing diastolic pressure to less than 100 mm Hg in 21 of the 26 subjects who completed the study. Compared to the last values on placebo, mean standing blood pressure was decreased by 15.6/12.0 mm Hg during the first 6 weeks of
medroxalol at mean daily doses of 388-407 mg. Addition of
hydrochlorothiazide permitted some decrease in
medroxalol dosage. Upon
medroxalol withdrawal, blood pressure and heart rate returned toward pretreatment values, with subjects continuing on
diuretic showing lower blood pressures than the untreated individuals. Tolerance to
medroxalol, with or without
hydrochlorothiazide, was good. Mild orthostatic
dizziness was the most frequent complaint associated with
therapy, but
postural hypotension was not found on physical examination.
Medroxalol appears to be effective and well tolerated for reducing the blood pressure of most patients with mild to moderate
hypertension and may be useful for chronic oral
therapy of this disease.