Doxazosin in renal impairment.

The pharmacokinetics of doxazosin given once daily are similar in patients both with normal and with impaired renal function and consequently doxazosin can be used effectively in both at similar doses. Renal blood flow is well preserved during long-term treatment but effects on glomerular filtration rates are less consistent and small reductions may occur. It is uncertain whether these reflect a reduction in perfusion pressure, progression of the underlying renal disease or a combination of the two. Postural hypotension may occur in some patients after an initial dose of 1 mg.