Overactive bladder drugs and constipation: a meta-analysis of randomized, placebo-controlled trials.
BACKGROUND
Anticholinergic drugs are commonly prescribed for symptomatic treatment of overactive bladder (OAB). While recent meta-analyses have characterized the prevalence of dry mouth among patients utilizing OAB medications, prevalence of constipation has not been systematically reviewed.


OBJECTIVE
To provide an effect measure for constipation associated with anticholinergic OAB drugs versus placebo.


METHODS
A meta-analysis of trials with darifenacin, fesoterodine, oxybutynin, solifenacin, tolterodine, and trospium was conducted. All randomized, placebo-controlled studies of anticholinergic OAB drugs published in English language and identified in Medline and Cochrane databases were considered for inclusion in this meta-analysis. Those meeting predetermined design characteristics and having sufficient duration (≥2 weeks) were included. Constipation-related data from all included studies were abstracted.


RESULTS
One hundred two English-language, randomized, placebo-controlled trials were originally identified. Thirty-seven studies were ultimately included in the analysis, involving 19,434 total subjects (12,368 treatment+7,066 placebo patients). The odds ratios for constipation compared with placebo were as follows: overall [odds ratio (OR) 2.18, 95% confidence interval (CI)=1.82-2.60], tolterodine (OR 1.36, 95% CI=1.01-1.85), darifenacin (OR 1.93, 95% CI=1.40-2.66), fesoterodine (OR 2.07, 95% CI=1.28-3.35), oxybutynin (OR 2.34, 95% CI=1.31-4.16), trospium (OR 2.93, 95% CI=2.00-4.28), and solifenacin (OR 3.02, 95% CI=2.37-3.84).


CONCLUSIONS
Our results demonstrate that patients prescribed anticholinergic OAB drugs are significantly more likely to experience constipation. Differences in muscarinic receptor affinities among individual agents may possibly account for the modest variation in constipation rates observed; however, such a determination warrants additional research.
Meek
Patrick D
PD
Research Institute for Health Outcomes, Department of Pharmacy Practice, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, NY 12208-3425, USA. Patrick.Meek@acphs.edu
Evang
Samuel D
SD
Tadrous
Mina
M
Roux-Lirange
Dianne
D
Triller
Darren M
DM
Gumustop
Bora
B
D000368:Aged; D000369:Aged, 80 and over; D001559:Benzhydryl Compounds / Q000009:adverse effects / Q000627:therapeutic use; D001572:Benzofurans / Q000009:adverse effects / Q000627:therapeutic use; D018680:Cholinergic Antagonists / Q000009:adverse effects* / Q000627:therapeutic use; D003248:Constipation / Q000139:chemically induced* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011759:Pyrrolidines / Q000009:adverse effects / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D053201:Urinary Bladder, Overactive / Q000188:drug therapy*
D001559:Benzhydryl Compounds; D001572:Benzofurans; D018680:Cholinergic Antagonists; D011759:Pyrrolidines; C526675:fesoterodine; C101207:darifenacin