[Drug adverse reactions leading to hospital admission]

Few studies have addressed how often adverse drug reactions cause hospital admissions in Brazil. This study was carried out in a university hospital looking for the patterns of drug utilization before hospital admission and the frequency of adverse drug reactions.

The study was developed in two steps. The first step evaluated the hospital admission morbidity patterns at an Internal Medicine ward during 1997, using the hospital register system. The second step was carried out in 1999 when a hospital-based intensive monitoring program was performed during a 4 months period. Patients admitted to this ward were interviewed for the drugs used during 15 days before admission, their morbidity patterns were described in detail, and the possibility of adverse drug reactions being the cause of hospital admission was evaluated.

During 1997, of the 938 patients admitted to the Internal Medicine ward, 46.6% were female patients, and a mean of 1.1 diagnosis per hospital admission was recorded. No adverse drug reaction was found. During the hospital-based intensive monitoring, of the 135 patients studied, 52% were female, 92% had used at least one drug before the hospital admission, and 42% had used self-medication. The mean of utilized drug was 3.7. Adverse drug reaction was the cause of or contributed to 6.6% of the hospital admissions.

Hospital-based intensive monitoring stimulates the reporting of drug adverse reactions and is an important resource for training in rational drug use.