Long term effects of sustained release verapamil on the renal and systemic haemodynamic parameters in hypertensive patients with mild to severe chronic renal failure.

Calcium antagonists such as verapamil are among the antihypertensive agents categorised as first line treatments for essential hypertension. They have also shown efficacy in secondary forms of hypertension, including hypertension associated with chronic renal failure, irrespective of the degree of renal impairment. Systemic and renal haemodynamic parameters, and renal function were analysed in 15 hypertensive patients with mild to severe chronic renal failure after a 2-week placebo period and after 4 weeks of administration of verapamil sustained release (SR) 240 mg/day. After 4 weeks of treatment with verapamil SR, blood pressure was normalised in all patients. Arterial pressure decreased as a result of the decrease in systemic vascular resistance, while cardiac output and heart rate remained unchanged. Verapamil therapy did not significantly affect left cardiac function curves. The normalisation of arterial pressure did not result in changes in the glomerular filtration rate; however, renal vascular resistance decreased significantly, although the filtration fraction remained unchanged. Renal blood flow increased significantly and there was a significant increase in uricosuria and a subsequent decrease in plasma uric acid levels. In conclusion, verapamil SR is an effective and well tolerated treatment for hypertension associated with chronic renal failure.