One hundred eighteen patients, aged between 65 and 87 years with 
mild-to-moderate hypertension were given placebo or isradipine (1.25 to 5 mg 
twice daily, or 2.5 to 10 mg once daily) following a three-week placebo period 
to evaluate its safety and efficacy in elderly patients. Dosage step-up was at 
three-week intervals. Blood pressure measurements were taken immediately before 
the morning dose (12 to 24 hours after the previous dose). At the end of the 
study, both supine and standing diastolic blood pressures were significantly 
lower with isradipine than with placebo. A 10-mm Hg reduction in supine 
diastolic blood pressure was achieved with once-daily isradipine in 65 percent 
and with twice-daily isradipine in 52 percent of patients, indicating sustained 
blood pressure control over the dose interval (12 to 24 hours). Adverse events 
were usually mild, transient, and typical for vasodilators. Isradipine did not 
produce more laboratory, clinical, or electrocardiographic abnormalities than 
did placebo. In conclusion, isradipine either once or twice daily at doses 
between 2.5 and 10 mg is an effective and well-tolerated treatment for 
mild-to-moderate hypertension in elderly patients.