Adverse drug reactions cost the NHS £466m a year

Adverse drug reactions account for 1 in 16 hospital admissions and cost the NHS £466m a year, according to a study in this week's BMJ.

Researchers assessed 18,820 patients aged over 16 years who were admitted to two NHS hospitals in Merseyside over a six-month period. Drug history and symptoms were used to determine if the admission had been caused by an adverse drug reaction.

A total of 1,225 admissions were related to an adverse drug reaction, giving a prevalence of 6.5%. The average stay was eight days, which accounted for 4% of the hospital bed capacity. The projected annual cost to the NHS of such admissions was £466m.

Although most patients recovered, 28 (2.3%) died as a direct result of the reaction. Most reactions were either definitely or possibly avoidable. Low dose aspirin, diuretics, warfarin, and non-steroidal anti-inflammatory drugs were most commonly implicated. Gastrointestinal bleeding was the most common reaction.

Adverse drug reactions are an important cause of hospital admissions, resulting in a considerable use of NHS beds and a significant number of deaths, say the authors. Many may be preventable through simple improvements in prescribing.

Measures are urgently needed to reduce the burden on the NHS, they conclude.