Central and autonomic nervous system side effects of ketanserin

A placebo controlled, randomized, double-blind cross-over study was carried out in 7 healthy volunteers in order to study the central and autonomic nervous system side effects of ketanserin in comparison to clonidine. Psychometric performance was assessed as well as electroencephalographic recordings (EEG), saliva production, mean arterial blood pressure (MAP) and pulse rate under placebo conditions (P, 10 ml saline), following 0.15 mg/kg ketanserin or 2 micrograms/kg clonidine i.v. administration. The sedation index as well as the deceleration of EEG frequencies clearly expressed sedation following both, ketanserin and clonidine. Saliva production was significantly decreased by ketanserin (p less than 0.05) and clonidine (p less than 0.01), respectively. MAP was only very slightly reduced by ketanserin, while clonidine caused a small but significant decrease (p less than 0.0001). The pulse rate changes did not reach a clinically important extent. Thus, sedation as main central nervous system side effect and reduction in salivation as autonomic nervous system side effect of ketanserin could be clearly quantified in comparison to placebo and clonidine.