Interaction Between Fluvoxamine and Sildenafil

In a randomised, double-blind, placebo-controlled, cross-over study in healthy men we will assess the effect of oral fluvoxamine (50mg qd on day 1-3; 100mg qd on day 4-10) on sildenafil kinetics (single oral 50mg dose on day 11). Sildenafil plasma concentrations will be determined by LC/MS. We will also assess the effect of sildenafil on venodilation induced by a constant dose-rate of the NO-donor sodium nitroprusside (SNP) during preconstriction with phenylephrine (dorsal hand vein compliance technique).

Inclusion criteria

• Healthy, male individuals, age: 18-45.
• Able and willing to give written informed consent

Exclusion criteria

• Hypotension ( 65 mmHg diastolic and  100 mmHg systolic blood pressure)
• Bleeding disorders in medical history
• Intake of medication impairing platelet function or influencing coagulation (for example aspirin, NSAID and others) during the preceding 4 weeks
• Known condition causing endothelial dysfunction (e.g. diabetes, hyperlipidaemia, arterial hypertension, hyperhomocysteinaemia, smoking)
• Anatomic deformity of the penis like angulation, penile fibromatosis (peyronie's disease) or diseases favouring priapism (e.g. leukaemia, plasmocytoma, sickle-cell anaemia)
• Regular medication and/or treatment with drugs within the preceding 4-6 weeks (exclusion has to be decided in each case)
• alcohol (>30 g/d) or drug abuse
• Acute or chronic illness
• Blood donation within the preceding 2 months
• Participation in clinical trial within 2 month before the study
• Drug and/or alcohol abuse.