Temporal profile of adverse drug reactions and associated clinical factors: a prospective observational study in a neonatal intensive care unit

Objective: Although adverse drug reactions (ADRs) are quite common in hospitalised neonates, pharmacovigilance activities in this public are still incipient. This study aims to characterise ADRs in neonates in a neonatal intensive care unit (NICU), identifying causative drugs, temporal profile and associated factors.

Design: Prospective observational study.

Setting: NICU of a public maternity hospital in Natal/Brazil.

Participants: All neonates admitted to the NICU for more than 24 hours and using at least one medication were followed up during the time of hospitalisation.

Primary outcome measures: Incidence rate and risk factors for ADRs. The ADRs were detected by an active search in electronic medical records and analysis of spontaneous reports in the hospital pharmacovigilance system.

Results: Six hundred neonates were included in the study, where 118 neonates had a total of 186 ADRs. The prevalence of ADRs at the NICU was 19.7% (95% CI 16.7% to 23.0%). The most common ADRs were tachycardia (30.6%), polyuria (9.1%) and hypokalaemia (8.6%). Tachycardia (peak incidence rate: 57.1 ADR/1000 neonates) and hyperthermia (19.1 ADR/1000 neonates) predominated during the first 5 days of hospitalisation. The incidence rate of polyuria and hypokalaemia increased markedly after the 20th day, with both reaching a peak of 120.0 ADR/1000 neonates. Longer hospitalisation time (OR 0.018, 95% CI 0.007 to 0.029; p<0.01) and number of prescribed drugs (OR 0.127, 95% CI 0.075 to 0.178; p<0.01) were factors associated with ADRs.

Conclusion: ADRs are very common in NICU, with tachycardia and hyperthermia predominant in the first week of hospitalisation and polyuria and hypokalaemia from the third week onwards.