• erectile dysfunction;
  • polypharmacy;
  • adverse events;
  • medications

Study Type – Symptom prevalence (population cohort)

Level of Evidence 1b

What's known on the subject? and What does the study add?

It is known that medical conditions such as diabetes, high blood pressure, high cholesterol, smoking and prescribed medications cause erectile dysfunction (ED). This has been studied at the molecular level and reported in population studies. The present study shows that, after accounting for known medical problems, there is a dose–response relationship, in which worsening degrees of ED are seen when a greater number of medications are taken, regardless if they are prescribed or over the counter.

The study can help primary care doctors and urologists to make a differential diagnosis of ED and it can also help improve patient's erectile function by tailoring and curtailing current medication use to maximize therapeutic benefit but minimize ED side effects in men, thus improving health-related quality of life.


  • • 
    To study the association between erectile dysfunction (ED) and polypharmacy use in a large, ethnically and racially diverse cohort of men enrolled in the California Men's Health Study (CMHS).


  • • 
    Men from the Kaiser Permanente Southern California (KPSC) health plan, enrolled in the CMHS in 2002, had an age range of 45–69 years. ED and comorbidities of these subjects were identified by questionnaire responses.
  • • 
    The number of drugs taken was determined from the year before enrollment through electronic pharmacy records and questionnaire responses.


  • • 
    Among the 37 712 (KPSC) subjects, 10 717 (29%) reported moderate or severe ED.
  • • 
    Across all age groups, ED was more prevalent as the number of medications increased.
  • • 
    In men taking 0–2, 3–5,6–9 and ≥10 medications, the percentage of men reporting moderate ED was 15.9, 19.7, 25.5 and 30.9%, respectively (P < 0.001).
  • • 
    With adjustment for age, race, smoking, diabetes, hypertension, hyperlipidaemia, peripheral vascular disease, coronary artery disease and body mass index, men taking >10 drugs were more likely to have ED (odds ratio = 2.32, 95% confidence interval 2.14–2.52) with evidence of a dose–response relationship.


  • • 
    These data suggest that the number of medications a man takes is associated with worse ED, even after comorbidities have been taken into account.