Alternative therapies for overactive bladder: Cannabis and urge incontinence

Abstract

Current drug therapies for overactive bladder (OAB) can produce variable outcomes and bothersome side effects, resulting in poor compliance. In patients with neurogenic detrusor overactivity and urge incontinence, evidence of a beneficial effect with oral cannabinoids is emerging. The rationale for their use was the discovery of cannabinoid receptors (CB1 and CB2), with CB1 receptors at various sites, including the brain and bladder, although the distribution of CB2 receptors is more limited. Cannabinoids also bind to vanilloid receptors, which have been the basis for intravesical therapies, such as capsaicin and resiniferatoxin. However, the use of capsaicin is limited by its pungency, whereas resiniferatoxin is limited by difficulties in delivery. Cannabinoids appear to work at several levels centrally and peripherally on detrusor smooth muscle, suggesting that they might produce similar effects in patients with neurogenic and nonneurogenic OAB. Large clinical trials of cannabinoids without psychotropic effects are required.