A controlled, randomized, single-blind, parallel-group study compared the effects of nicardipine hydrochloride/hydrochlorothiazide (HCTZ) with those of pindolol/HCTZ in treatment of essential hypertension. The study included 43 patients aged 30 - 64 years with supine diastolic blood pressures between 95 and 125 mmHg at baseline. Patients initially received 50 mg/day HCTZ for 6 weeks and those patients whose diastolic blood pressure remained at or above 90 mmHg at week 6 [n = 29] completed a 6-week comparative phase in which they were given, in addition, either 30 mg nicardipine hydrochloride or 5 mg pindolol three times daily. Nicardipine was more effective than pindolol as a second-line treatment in controlling blood pressure but, because patients who were treated with nicardipine/HCTZ had higher baseline blood pressures, significance was lost when results were adjusted for the baseline blood pressure values. Treatment was described as 'very good' by 71.4% of patients in the nicardipine/HCTZ group and by 53.9% of those in the pindolol/HCTZ group; thus, both second-line antihypertensives were well accepted. Although 45% of patients in of each treatment group reported treatment-related adverse events, none experienced postural hypotension and no adverse event was unexpected.