Antimuscarinic drugs to treat overactive bladder

Abstract

A 45 year old woman presents to her general practitioner complaining of troublesome urinary symptoms increasingly affecting her quality of life. She is currently voiding more than 10 times a day and rising three times at night. In addition she notices a sudden urgent desire to void and on two occasions has leaked urine before reaching the toilet. She gives no history of urinary tract infection or haematuria. Her periods remain regular. In the past she has had two vaginal deliveries, has no significant medical history, and is not taking any medication. Pelvic examination is unremarkable and urine analysis normal. Ultrasound examination shows no post-void residual urine. Based on the history, clinical examination, and basic investigations you make a symptomatic diagnosis of overactive bladder. After discussing her bladder symptoms, you offer lifestyle advice including the moderation of fluids and reduction of caffeine intake. In addition you refer her for bladder retraining and start treatment with antimuscarinic drugs. Overactive bladder is the term used to describe the symptom complex of urinary urgency, usually accompanied by frequency and nocturia, with or without urge urinary incontinence, in the absence of urinary tract infection or other obvious pathology.1 Epidemiological studies in North America have reported a prevalence of overactive bladder in women of 16.9%, and the prevalence increases with age—from 4.8% in women under 25 years to 30.9% in those aged over 65 years.2 Prevalence data from Europe are similar, with frequency the most commonly reported symptom (85%), and 54% reporting urgency and 36% urge incontinence.3 The symptoms of overactive bladder are most likely due to involuntary contractions of the detrusor muscle during the filling phase of the micturition cycle; abnormalities in afferent sensation may also play a role. Detrusor overactivity1 is mediated by acetylcholine induced stimulation of muscarinic receptors …