Ketanserin is a specific α1-receptor antagonist, which also has anti-serotonergic properties. The drug reduces arteriolar resistance and venous capacitance. The α1-receptor blocking capacities of ketanserin are not sufficient to cause a decrease in blood pressure, thus an underlying mechanism, such as a central action, might be there.
Ketanserin is indicated for the treatment of hypertension (>110mm Hg) during pre-eclampsia. The most common side effects are loss of concentration, headache, dizziness and fatigue.
An ECG must be checked before treatment and the first 24 hours after onset of treatment. Parenteral administration of 5-10 mg is recommended in case of hypertension during pregnancy.
Check the cardiology section for more information on α-blockers.
I. Ketanserin and methyldopa’s site of action is the vascular smooth muscle.
II. Ketanserin, like methyldopa, is an α-1 blocker.
Extra info: Close Methyldopa’s site of action is in the CNS (pons). Methyldopa is an α-2 blocker: it blocks the presynaptic α-2 receptor, which inhibits norepinephrine secretion and ligation the α-1 receptor on the postsynaptic membrane.