['To assess the pharmacodynamic effects of coadministered vardenafil and tamsulosin in patients with benign prostatic hyperplasia (BPH) undergoing stable tamsulosin therapy.', 'In this Phase 1, placebo-controlled, two-stage, two-way, crossover study, 22 patients undergoing stable (longer than 4 weeks) tamsulosin therapy for BPH (18 using 0.4 mg and 4 using 0.8 mg tamsulosin daily) received vardenafil 10 mg (or placebo), followed by vardenafil 20 mg (or placebo), simultaneously with tamsulosin. The mean maximal change from baseline with vardenafil use versus placebo was evaluated for supine and standing blood pressure and heart rate for up to 6 hours after dosing.', 'In patients receiving vardenafil 10 mg, the mean maximal change from baseline versus placebo in supine systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate was -4.5 mm Hg (95% confidence interval [CI] -8.2 to -0.8), -2.3 mm Hg (95% CI -4.9 to 0.4), and 3.7 beats per minute (95% CI 1.1 to 6.3), respectively. In patients receiving vardenafil 20 mg, the mean maximal change from baseline versus placebo in supine SBP, DBP, and heart rate was -4.0 mm Hg (95% CI -6.3 to -1.8), -2.9 mm Hg (95% CI -5.6 to -0.2), and 0.8 beats per minute (95% CI -1.2 to 2.9), respectively. These hemodynamic changes were similar to those obtained in the standing position. Two placebo patients and 1 vardenafil 10-mg patient had a drop of 20 mm Hg or more in standing DBP; 1 vardenafil 10-mg patient had a standing SBP drop of 30 mm Hg or more. No patient exhibited symptomatic hypotension (SBP less than 85 mm Hg with dizziness). Three patients receiving vardenafil 20 mg/tamsulosin 0.4 mg reported dizziness, but never had an SBP of less than 95 mm Hg. No serious adverse events were reported.'] Does simultaneous administration of vardenafil and tamsulosin induce clinically significant hypotension in patients with benign prostatic hyperplasia?