Oxybutynin and cognitive dysfunction.

Anticholinergic drugs have been used since the 19th century, when belladonna alkaloids were first given for treatment of Parkinson's disease. Their use declined because they were poorly tolerated, particularly by elderly patients. Recently, anticholinergic drugs have started to be used again for treating detrusor instability and hyperreflexia. Oxybutynin is an antimuscarinic used for this purpose, and its efficacy and adverse effects have been described.1 2 We report four cases of cognitive dysfunction in association with oxybutynin treatment. Case 1 —A 79 year old man with Parkinson's disease, chronic obstructive pulmonary disease, peptic ulcer disease, and irritable bladder was seen regularly in the clinic for Parkinson's disease at this hospital. He was taking selegiline, co-beneldopa, ranitidine, theophylline, intermittent courses of prednisolone, and inhaled beclomethasone dipropionate and salbutamol. In May 1994 he developed mild cognitive impairment. Selegiline was discontinued; this resulted in a noticeable improvement. His score in the abbreviated mental test was 9/10. Later that year he started taking oxybutynin (2.5 mg three times a day) for his urinary symptoms. …