Objectives  

To investigate the use of drugs, the extent and pattern of unlicensed and off-label use, and the potential relationship between off-label drug use and adverse drug reactions in northeastern Brazil.

Methods  

A follow-up study of drug utilization in a general ward of a pediatric reference hospital, involving patients hospitalized for more than 24 h. Prescriptions and medical records were reviewed daily from August to December 2001. Drug licensing status of all prescriptions given to these patients was determined.

Results  

A total of 272 patients were admitted during the study, 265 (97.4%) of whom received one or more drugs. The median number of drugs/patient was 6 (1–18), and the most frequent diagnosis was pneumonia (29.4% of patients). The therapeutic class most prescribed was anti-infectives for systemic use (68.8% of all children). In all, 82.6% of children received at least one unlicensed or off-label drug, and 17% received both an unlicensed and an off-label drug. Dose/frequency was the most common form of off-label drug use. Off-label drug use was significantly associated with adverse drug reactions (relative risk 2.44; 95% CI 2.12, 2.89).

Conclusions  

Although off-label drug use is a complex issue and is not synonymous with inappropriate drug use, a high rate of unlicensed/off-label drug use was found and was also associated with an increased risk of adverse drug reactions. More efforts are needed to increase rational drug use in children.