Based on the results of interaction studies conducted with vardenafil in patients with benign prostatic hyperplasia (BPH) on stable tamsulosin or terazosin therapy: • When vardenafil was given at doses of 5, 10 or 20 mg on a background of stable therapy with tamsulosin, there was no symptomatic reduction in blood pressure, although 3/ 21 tamsulosin treated subjects exhibited transient standing systolic blood pressures of less than 85 mmHg. • When vardenafil 5 mg was given simultaneously with terazosin 5 or 10 mg, one of 21 patients experienced symptomatic postural hypotension.