The antihypertensive efficacy of ketanserin in the elderly evaluated by ambulatory blood pressure measurement.

To assess the role of the serotonin antagonist ketanserin in the management of hypertension in the elderly, 12 patients with a mean age of 68 years (range 60-79 years) were treated with ketanserin in a randomised double-blind placebo-controlled cross-over trial. Clinic BP, ambulatory BP, renal function, and pharmacokinetics were assessed. The doses of ketanserin used were 40 mg (ten patients) and 20 mg (two patients) twice daily for 8 weeks. Mean clinic sitting BP was reduced from 169 +/- 5/98 +/- 2 on placebo to 155 +/- 5/88 +/- 3 mmHg (NS/P less than 0.05/P less than 0.05) and standing pressure from 168 +/- 6/100 +/- 3 to 157 +/- 5/91 +/- 3 mmHg (NS/P less than 0.01). Mean ambulatory systolic BP was unaffected by active treatment (167 +/- 7 vs 164 +/- 5) while diastolic pressure was lowered from 99 +/- 2 to 94 +/- 2 mmHg (P less than 0.05). This effect appeared to be mainly confined to the first two hours after drug administration. Renal blood flow was unaltered by treatment. The mean plasma half-life of ketanserin was 20.9 +/- 5.5 hours. Side effects were minimal. In conclusion, while ketanserin may be effective as assessed in the clinic, its efficacy on ambulatory monitoring is substantially less impressive.