Oxybutynin has been "consistently linked" with dementia and cognitive impairment, say researchers from the Henry Ford Hospital in Detroit, but doctors rarely monitor patients and only around 9 per cent of patients have a neurological examination before they start taking it.
Despite its side effects, oxybutynin is still the drug of choice in the US, where it's prescribed to 27 per cent of elderly people with overactive bladder. Its usage around Europe varies, from as little as 7 per cent of patients in Germany, Austria and Switzerland, and up to 70 per cent in Italy.
Oxybutynin is an antimuscarinic, a family of drugs derived from mushrooms that are designed to control overactive bladder, a common problem that affects around 9 per cent of the over-65s. Oxybutynin is the cheapest option in the antimuscarinic family, which probably is the reason it is so frequently prescribed.
It may be a false economy, however. There's solid evidence to show it is linked to greater cognitive decline in the elderly, and there are safer options—even within the antimuscarinic family—that could be prescribed instead.