Chemists in south-east London are inviting patients to bring in their medicines for a health check as part of a King's College London research project.
Seventeen dispensing chemists have joined the year-long project organised by King's pharmacy department, and are asking patients to empty the contents of their medicine cabinets into brown paper bags and bring them in for investigation.
Alan Nathan, lecturer in community pharmacy, said research shows that many patients are not getting the maximum benefit from medicines because they do not use them as their doctor intended.
Researchers have given chemists a questionnaire to go through with customers, keying the results into a laptop computer. This determines whether the patient knows how to take the drugs, and whether there could be side-effects from the interaction of prescribed drugs and those bought over the counter.
The project, funded from National Health Service money to improve family healthcare following the Tomlinson report on London's health services, will evaluate the contribution chemists can make to improving primary healthcare and saving money on the NHS drugs bill.
Mr Nathan said that in every case so far, the chemist had to intervene in some way. "Patients often aren't aware that they've got a problem until you ask them questions. They may have suffered side effects for years without realising that this is caused by the medicine they're taking."
The chemists will also dispose of drugs which are out of date or no longer used.