Does acute serotonergic type-2 antagonism reduce blood pressure? Comparative effects of single doses of ritanserin and ketanserin in essential hypertension.
We have studied the acute effects of the serotonergic type-2 (5-HT2) antagonists ketanserin and ritanserin given as single oral doses to patients with essential hypertension. Ketanserin has alpha 1-antagonist properties, whereas ritanserin is largely devoid of alpha 1-receptor binding affinity. Ketanserin (40 mg orally) caused a significant reduction (p less than 0.03) of sitting mean arterial pressure over the 8-h period following drug administration by an average of 15.4 +/- 3.2 mm Hg (mean +/- SEM) as compared to a reduction of 8.5 +/- 2.2 following placebo. In contrast, ritanserin had no significant effect on blood pressure compared to placebo; sitting mean arterial pressure was reduced by 9.0 +/- 2.6 and 10.8 +/- 1.8 mm Hg after administration of 10 and 20 mg, respectively, of ritanserin. There were no significant differences in pulse rate among placebo, ketanserin, or ritanserin phases. Ritanserin caused a reduction in the hostility score (p less than 0.05) as measured by the Multiple Affect Adjective Check List; ketanserin had no significant effects. The highly selective 5-HT2 antagonist ritanserin, given in a dose which caused measurable alteration of psychological function tests, had no acute effects on blood pressure. The acute antihypertensive effects of ketanserin are not caused by 5-HT2 antagonism alone, but are likely to be dependent on its alpha 1-antagonistic properties.
D000328:Adult; D000339:Affect / Q000187:drug effects; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology; D007650:Ketanserin / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010880:Piperidines / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D016713:Ritanserin
D010880:Piperidines; D011985:Receptors, Serotonin; D016713:Ritanserin; D007650:Ketanserin