Scottish patients vulnerable to adverse drug reactions (ADRs) are being prescribed medicine combinations likely to result in admission to hospital, University of Dundee researchers have warned.

In a study of more than 1.76 million patients from 315 Scottish GP practices, 139,000 were found to be vulnerable to ADRs, of whom 19,308 were found to have at least one high-risk item on their prescriptions.

While not all high-risk prescribing was inappropriate, the study, published in the BMJ, showed "existing activity to improve prescribing is insufficiently focused on safety", the authors from the University of Dundee concluded.

Common problems included 50 per cent of patients aged over 75 prescribed an NSAID without gastroprotection, with one in 10 patients with heart failure also prescribed NSAIDs.

Other issues raised included the lack of a weekly dose with methotrexate, or methotrexate 2.5mg and 10mg being co-prescribed; and antiplatelets or a high-risk antibiotic being prescribed with warfarin.