Important drug–drug interactions for treatments that target overactive bladder syndrome

Overactive bladder (OAB) is the term used to describe the symptom complex of urinary urgency,usually accompanied by frequency and nocturia, with or without urgency urinary incontinence, in the absence of urinary tract infection or other obvious pathology. It is a common distressing condition that significantly impairs quality of life(QoL). After lifestyle advice and bladder retraining,antimuscarinic drugs are most commonly used to treat OAB.

The antimuscarinics in common use are all metabolised through differing mechanisms. Therefore, the risk of an enhanced drug effect is increased when the potentially interacting substrates compete for the same metabolic pathways. The aim of this review is to provide an overview on potential drug–drug interactions with special emphasis on high-risk groups and clinically important consequences of these interactions

Knowledge of current important drug interactions is vital whilst prescribing antimuscarinics, particularly in high-risk groups. Novel therapies, such as beta 3 agonists or alternative drug delivery systems, such as the oxybutynin vaginal ring, might provide alternative options where these interactions are unavoidable.