Summary
We have given the selective 5 HT2 antagonist ritanserin in a dose of 10 mg twice daily for 4 weeks in a double-blind, randomized, placebocontrolled, parallel group study of 18 patients with untreated essential hypertension.
The fall in single platelet count due to 5 HT-induced platelet aggregation was significantly reduced by ritanserin compared with placebo (p<0.05).
There were no significant changes in supine or erect blood pressure or heart rate after ritanserin compared to placebo. Forearm blood flow, measured by mercury-in-strain gauge venous occlusion plethysmography, was not significantly altered by ritanserin.
Ritanserin caused prolongation of the QTc interval by 41 (SEM 11) ms (p<0.05 compared to placebo) but had no detectable effect on QRS duration, features suggestive of Class III antiarrhythmic activity.
These findings do not support an independent role of the 5 HT2 receptor in maintaining raised arterial pressure in essential hypertension.
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Stott, D.J., Saniabadi, A.R., Hosie, J. et al. The effects of the 5 HT2 antagonist ritanserin on blood pressure and serotonin-induced platelet aggregation in patients with untreated essential hypertension. Eur J Clin Pharmacol 35, 123–129 (1988). https://doi.org/10.1007/BF00609240
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DOI: https://doi.org/10.1007/BF00609240