Thousands of patients prescribed high-risk drugs

According to research published at, GPs prescribed high-risk medications for thousands of patients in Scotland who are especially vulnerable to adverse drug events (ADEs), exposing them to potential harm.

A number of medications or scenarios previously flagged as high risk included non-steroidal anti-inflammatory drugs for certain patients, prescribing a new drug to a patient on the blood-thinning medication warfarin, prescribing drugs when patients have heart failure, and prescribing antipsychotic drugs for patients with dementia.

Prof. Bruce Guthrie from Dundee University and colleagues expanded this list, developing 15 indicators to examine how often patients susceptible to ADEs were prescribed high-risk, potentially harmful drugs.

They used the indicators to review data from 315 Scottish General Practices with 1.76 million patients, of which 139,404 (7.9%) were identified as being particularly vulnerable to ADEs.

The results showed that 19,308 (13.9%) who were in the vulnerable group were prescribed one or more high-risk medications.

Some prescribing will be appropriate, as prescribers and patients balance risks and benefits when there may be no clearly “correct” course of action, but the study also uncovered significant variation in the prescribing practices between the GPs’ surgeries surveyed. Since the variation couldn’t be explained by the patient case mix, the researchers say it suggests there’s considerable scope to improve those prescribing practices.

Led by Prof. Guthrie, the authors point out how prior studies showed GP prescribing can cause considerable harm, and they highlight that “adverse drug events (ADEs) account for 6.5% of all hospital admissions, over half of which are judged to be preventable.”

Patients might be vulnerable to high-risk drugs due to their age, other existing illnesses, or because of other prescription medications they may be on. The authors caution that GPs need to be alert to these risk factors, and be careful about the drugs they prescribe to these patients.

SOURCE: “High risk prescribing in primary care patients particularly vulnerable to adverse drug events: cross sectional population database analysis in Scottish general practice” BMJ, June 22, 2011 ABSTRACT