A pharmacokinetic study of prazosin in patients with varying degrees of chronic renal failure.

Pharmacokinetic parameters of prazosin (t1/2, tmax, Cmax and AUC have been studied in 18 hypertensive patients with varying degrees of chronic renal failure (serum creatinine ranging from 1.6 to 11.4 mg/dl). An oral dose of 2 mg of prazosin was added to the preexisting antihypertensive medication. The degree of renal impairment did not influence the peak drug concentration, the time to peak or the serum half-life. On the other hand, the hypotensive action after 2 mg prazosin, was more pronounced in patients with severe chronic renal failure. This effect could not be explained by a difference in the pharmacokinetics of prazosin in severe as compared to moderate chronic renal failure or to normal renal function.