Researchers have linked commonly taken drugs to mental decline and death in older people.
The study involved 13,000 people and looked at 80 drugs including painkillers, blood thinners, eye drops for glaucoma and antihistamines.
Each drug was examined for the 'anticholinergic activity' side-effect, which affects the brain by blocking the acetylcholine neurotransmitter and was then given a ranking from one to three according to the strength of this effect.
Drugs given a rating of one had the mildest effect, while those ranked three were of most serious concern.
Medications given a rating of three include widely available and commonly prescribed drugs such as antihistamine chlorphenamine, which is used in the Piriton range, anti-depressant paroxetine, used in Seroxat, and the Ditropan incontinence drug oxybutynin.
The researchers, who published their findings in the Journal of the American Geriatrics Society, found patients who take a variety of drugs that are all ranked one face increased risk of decline and ultimately death, and the threshold for damage in these patients was a total score of about four.
"The report illustrates the shortcomings of the benefits these drugs are supposed to have and the fact that the side-effects of drugs available on prescription from physicians must be more vigorously restudied and tested. It is not good to inflict long-term serious damage to people's health by giving them medicines that would also harm their wellbeing" - Jan Drena, UK