The countering of diazoxide-induced vasodilatation by tenoxicam in normal volunteers.

The effect of the nonsteroidal anti-inflammatory drug, tenoxicam, on diazoxide-induced lowering of standing diastolic blood pressure was explored in 10 normal volunteers. With diazoxide there was a significant fall in the 5-min standing diastolic pressure, i.e. a median drop of 15.5, 11.0, 9.5 and 7.0 mm Hg at 10, 35, 75 and 105 min, respectively, but with the tenoxicam-diazoxide regimen this pressure did not differ significantly from baseline at any time point. Tenoxicam did not modify the diazoxide-induced changes in blood glucose and plasma insulin. It may be that prostaglandins normally contribute to the lowering of peripheral vascular resistance, or that acutely-administered diazoxide enhances the release of vasodilatory prostaglandins.