Ketanserin effect on limb perfusion and arterial collaterals

Arterial collateral flow and major vessel patency are important in patients with intermittent claudication. Activity of serotonin released from platelets has been demonstrated experimentally, and serotonin antagonists have been investigated in treadmill testing. Ketanserin, a serotonin (5-HT/sup 2/) antagonist, was investigated in 20 patients with intermittent claudication to assess its effect on collaterals. Blood-pressure ratio (thigh/arm), mercury-strain gauge plethysmography, Doppler pressures, and repeat arteriography were performed. Ketanserin (3-30 μg/kg IA) increased collateral vessel size on angiography in 12 patients (60%) and increased blood-flow ratio and plethysmogrpahy pressures on average. These observations, confirming clinical studies that some patients show a dramatic response and others do not, might prove useful in identifying patients who will respond to ketanserin for occlusive vascular disease