Phosphodiesterase inhibitors for erectile dysfunction in patients with diabetes mellitus

Erectile dysfunction is a common multi-factorial complication of diabetes mellitus. Newer medications, like the so-called PDE-5 inhibitors result in enhancement of penile erection. The introduction of sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis), have altered the management of erectile dysfunction. In this review we assessed the effect of these agents on erectile dysfunction in diabetic people. Eight studies with 976 men randomised to PDE-5 inhibitor therapy and a duration of mainly 12 weeks were evaluated. Compared to placebo treatment, these agents showed favourable effects in scores estimating sexual life, with an increased rate of adverse effects like headache and flushing after PDE-inhibitor therapy. Mortality was not reported in any of the included trials. Quality of life, with the exception of scores for sexual life, was not relevantly affected. If taken as prescribed, PDE-5 inhibitors comprise a valuable treatment option for erectile dysfunction in men with diabetes.

Authors' conclusions: 

Sufficient evidence exists that PDE-5 inhibitors form a care that improves erectile dysfunction in diabetic men.

Read the full abstract...

Erectile dysfunction is a common multi-factorial complication of diabetes mellitus. Numerous strategies have been tried to overcome this diabetic complication. In recent years, phosphodiesterase type 5 (PDE-5) inhibitors have been introduced in the management of erectile dysfunction.


The objective of this review was to assess the effect of PDE-5 inhibitors on the management of erectile dysfunction in diabetic men.

Search strategy: 

Studies were obtained from computerised searches of MEDLINE, EMBASE and The Cochrane Library.

Selection criteria: 

Randomised controlled trials, in which treatment with PDE-5 inhibitors was compared to control, in diabetic patients with erectile dysfunction.

Data collection and analysis: 

Two reviewers independently extracted data and assessed trial quality.

Main results: 

Eight randomised controlled trials were identified. A total 976 men were allocated to receive a PDE-5 inhibitor and 741 were randomised to the control groups. Overall, 80% of the participants suffered from type 2 diabetes mellitus. The weighted mean difference (WMD) for the International Index of Erectile Function (IIEF) questions 3 and 4 (frequency of penetration during and maintaining erection to completion of intercourse) was 0.9 (95% CI 0.8 to 1.1) and 1.1 (95% CI 1.0 to 1.2) at the end of the study period, in favour of the intervention group. The WMD for the IIEF erectile dysfunction domain at the end of the study period was 6.6 (95% CI 5.2 to 7.9) in favour of the PDE-5 inhibitors arm. The relative risk (RR) for answering "yes" to a global efficacy question ( "did the treatment improve your erections?") was 3.8 (CI 95% 3.1 to 4.5) in the PDE-5 inhibitors compared with the control arm. The WMD between the percentage of successful attempts in the PDE-5 inhibitors and in the control arm was 26.7 (95% CI 23.1 to 30.3). Mortality was not reported in any of the included trials. Adverse cardiovascular effects were reported in one study. Headache was the most frequent adverse event reported, flushing was the second most common event, with upper respiratory tract complaints and flu like syndromes, dyspepsia, myalgia, abnormal vision and back pain also reported in a descending order of frequency. The overall risk ratio for developing any adverse reaction was 4.8 (CI 95% 3.74 to 6.16) in the PDE-5 inhibitors arm as compared to the control.