Effect of ketanserin on pain perception in arterial hypertension

An association between increased tolerance to pain and arterial hypertension has been reported in experimental animals and confirmed in humans. The underlying mechanisms remain elusive. We have recently reported that diuretics and beta-blocking treatment do not influence pain sensitivity, despite significant reductions in arterial blood pressure. In the present study, ketanserin was evaluated. As in previous work, pain perception was assessed with a tooth pulp tester. Ten hypertensive subjects were studied basally, after 15 days and after 3 months of ketanserin treatment (20 mg twice daily). Significant reductions in arterial blood pressure and of pain thresholds were observed, but no correlation between these changes occurred. These preliminary data indicate that, contrary to other hypotensive drugs, ketanserin tends to decrease or reverse the abnormality in pain modulation observed in hypertensive patients. The lack of a correlation between effects on blood pressure and pain sensitivity seems, however, to favor the hypothesis of two independent underlying mechanisms.