Regression of left ventricular hypertrophy and systolic function in hypertensive patients during long-term treatment with ketanserin

Serotonin and serotonin antagonism in cardiovascular and non-cardiovascular disease

Serotonin, or 5-hydroxytryptamine, is a naturally-occurring vasoactive substance found primarily in the brain, enterochromaffin tissue, and blood platelets. It has diffuse cardiophysiologic effects. The multiple effects of serotonin on blood vessels can be explained by the existence of 2 serotonergic receptor subtypes (the S1 receptor mediates vasodilation, and the S2 receptor vasoconstriction). Serotonin via the S2 receptor also augments the actions of several other vasoconstricting substances. Serotonin may be responsible for causing, or at least perpetuating, some forms of systemic hypertension through peripheral and central nervous system (CNS) actions. Ketanserin is a highly selective S2-serotonergic antagonist with additional alpha-adrenergic blocking activity, which has been proposed as a therapy for various cardiovascular diseases including hypertension. It has been shown to be more effective than placebo in treating hypertension and comparable in effectiveness to other antihypertensive drugs. Its major side effects relate to the CNS, and prolongation of the electrocardiogram QT interval has been described. Caution must be used when using ketanserin in patients receiving potassium- and magnesium-losing agents, because of the risk of torsades de pointes. Ketanserin has potential utility in the treatment of eclampsia, peripheral vascular disease, carcinoid syndrome, and "shock lung." The drug is not yet approved for clinical use in the United States.

Comparison of ketanserin and celiprolol on regression of left ventricular hypertrophy in older hypertensive patients

The effects of ketanserin, a specific serotonin2-receptor agonist, and celiprolol, a new, highly cardioselective beta 1 blocker with partial beta 2 agonist activity and peripheral vasodilating properties, on left ventricular (LV) structure and function were assessed in 60 older hypertensive patients (greater than 55 years) with clinical LV hypertrophy (LV mass index greater than 130 g/m2). The patients were studied using echocardiography after 1 month of placebo treatment, and 6 and 18 months of monotherapy with active drug. Ketanserin and celiprolol lowered blood pressure to normal levels. Heart rate did not change with ketanserin and fell moderately (-5%) with celiprolol (p less than .001). Regression of LV hypertrophy was achieved with the use of either medication (p less than .0001), although the magnitude of reduction in LV mass was greater with celiprolol at both 6 months (-10% vs -5%, p = .001) and 18 months (-13% vs -7%, p = .002). While LV volume did not change with either drug, celiprolol tended to decrease it, resulting in a 5% reduction in cardiac index (p = .01), which was associated with mild bradycardia. Ketanserin did not change LV ejection fraction, whereas celiprolol caused a slight (1.5%) long-term improvement (p = .003). Systolic wall stress and total peripheral resistance decreased with both agents (p less than .01), with no between-group differences. In conclusion, anti-hypertensive treatment of older persons with ketanserin or celiprolol achieves regression of LV hypertrophy without associated deleterious effects on LV function.