Although benign prostatic hyperplasia (BPH) is the most common cause, the aetiology of lower urinary tract symptoms (LUTS) is multifactorial. Clinical guidelines for BPH suggest evaluating other potential sources of LUTS (e.g. concomitant medication use) before initiating pharmacotherapy or surgical intervention.

A study in the Archives of Internal Medicine has assessed the cross-sectional association between current use of selected common medications and LUTS among men enrolled in the California Men's Health Study (CMHS). It involved men aged 45 to 69 years from the Kaiser Permanente California Medical Care Program. A total of 84,170 participants completed questionnaires and were eligible for study inclusion. Following exclusions for a range of conditions, 63,579 subjects were eligible for analysis. Pharmacy records were assessed for prescriptions of antidepressants, antihistamines, bronchodilators, non-urinary anticholinergics, sympathomimetics, and diuretics during the baseline survey period with at least 1 prescription filled.

The following findings were reported:

• In unadjusted analyses, every medication class was associated with LUTS. When adjusted for region, age, and race/ethnicity, bronchodilators and antidepressants had the strongest associations.

• Significant associations were found more often among men without BPH, particularly for sympathomimetic, diuretic, and antidepressant medications.

• When study medications were combined into any vs. none, the odds ratio was 1.29 (95% CI, 1.25 to 1.34) without adjustment for BPH and 1.28 (1.24 to 1.32) with adjustment for BPH. When stratified by presence of BPH, the OR was 1.31 (1.27 to 1.36) for those without BPH and 1.16 (1.08 to 1.25) for those with BPH.

• Estimates of aetiologic fraction suggest that antihistamines, bronchodilators, diuretics, and antidepressants account for approximately 1%, 2%, 3%, and 4% of LUTS, respectively. These percentages were slightly attenuated in men with BPH. Use of any of these medications could account for 10% of LUTS, compared with 29% of symptoms associated with BPH.

The researchers conclude that “if these observed associations represent cause and effect relationships, these medications account for 10% of LUTS, an effect approximately one-third of that for BPH. This underscores the importance of assessing medications in the differential diagnosis of LUTS.”