Impact of diabetes mellitus on the severity of erectile dysfunction and response to treatment: analysis of data from tadalafil clinical trials

Aims/hypothesis. A retrospective analysis of pooled data from twelve placebo-controlled trials was conducted to characterise the efficacy and safety of tadalafil for the treatment of erectile dysfunction in men with diabetes compared with that in men without diabetes. Methods. Patients were randomly allocated to tadalafil 10 mg, 20 mg, or placebo, taken as needed for 12 weeks. The study population comprised 637 men with diabetes (mean age 57 years) and 1681 men without diabetes (mean age 56 years). Results. At baseline, patients with diabetes had more severe erectile dysfunction than patients without diabetes, with mean International Index of Erectile Function (IIEF) erectile function domain scores of 12.6 and 15.0 respectively (p<0.001). Compared with placebo, tadalafil 10 mg and 20 mg improved all primary efficacy outcomes in both patient groups (p<0.001). Men with diabetes receiving tadalafil 20 mg experienced a mean improvement of 7.4 in their IIEF erectile function domain score against baseline versus 0.9 for placebo (p<0.001). This group reported on average that 53% of their attempts at intercourse were successful, compared with 22% for placebo (p<0.001 for the change from baseline). Baseline IIEF erectile function domain scores correlated inversely with baseline HbA(1)c levels. The responses to tadalafil were similar regardless of levels of baseline glycaemic control, diabetic therapy received, or previous use of sildenafil. Conclusions/interpretation. Despite more severe baseline erectile dysfunction in men with diabetes, tadalafil was efficacious and well tolerated in this population. As reported for other phosphodiesterase 5 inhibitors, the response to tadalafil was slightly lower in men with diabetes than in men without diabetes.