(unbound) sildenafil and its active N-desmethyl metabolite were 45% and 57%, respectively. Renal Insufficiency: In volunteers with mild (CLcr=50-80 mUmin) and moderate (CLcr=30-49 mUmin) renal impairment, the pharmacokinetics of a single oral dose of VIAGRA (50 mg) were not altered. In volunteers wit

ve N-desmethyl metabolite were 45% and 57%, respectively. Renal Insufficiency: In volunteers with mild (CLcr=50-80 mUmin) and moderate (CLcr=30-49 mUmin) renal impairment, the pharmacokinetics of a single oral dose of VIAGRA (50 mg) were not altered. In volunteers with severe (CLcr=c30 mUmin) renal i