Can medications affect mental capacity?

YES - older people and anyone with a ‘vulnerable’ brain may experience side effects from certain medications which can alter behaviour which, in turn, may impair mental capacity. This does not mean that everyone will experience the same effects, but that some people will be prone to such side effects.

Some of the offending drugs include the older medications for an overactive bladder, such as oxybutynin and tolterodine. They have anticholinergic effects which can cause confusion (delirium) and falls in older people. Other medications which can cause confusion are opiates such as codeine and morphine, especially in those who have not taken them before, as well as steroids such as prednisolone. The delirium is temporary, typically resolving after stopping the offending medications.

This is not an exhaustive list by any means but highlights commonly prescribed medications that are frequent culprits. It does not mean, however, that people should stop taking these medications as not everyone will experience side effects. It is also unwise to stop medications without first discussing with a doctor, but if an older relative becomes confused after starting a new medication, it is worthwhile having a chat with the GP.