Long-term effects on central haemodynamics and body fluid volumes of ketanserin in essential hypertension studies at rest and during dynamic exercise.
The long-term haemodynamic effects of ketanserin, a new serotonin-antagonist, was examined in 13 patients of both sexes (age range 24-62 years) with mild and moderate essential hypertension (EH). Cardiac output (CO) and intra-arterial blood pressure (BP) were measured at rest and during exercise before and after nine months of therapy. On ketanserin the mean casual BP was lowered by 15/21 mmHg to 152/91 mmHg and five of the 13 patients became 'normotensive' (BP less than 140/90 mmHg). The intra-arterial systolic pressure fell by 5-8% and the diastolic pressure by 5-11% from pretreatment levels at rest supine, sitting and during 50, 100 and 150 W exercise. The fall in BP was associated with a reduction in CO at rest while during exercise both a fall in CO and in total peripheral resistance contributed to the hypotensive effect. The fall in CO was due to a reduction in heart rate (average: -4 to 8 beats/min). The stroke volume remained unchanged in all settings and oxygen consumption was not affected by the drug. Body weight and body fluid volumes did not change significantly. Eight patients complained of drowsiness and lack of concentration. It is concluded that in mild and moderate EH ketanserin induces a moderate BP reduction associated with a fall in CO. There is no large vasodilating effect after long-term ketanserin treatment either at rest or during exercise. Ketanserin does not influence body fluid balance. The incidence of side-effects is high.