Adverse drug reactions in Singaporean children

Allergic reactions to drugs are considered rare in the paediatric population. Host genetic and environmental factors influence the reported incidence and characteristics of adverse drug reactions (ADRs), and cause significant variation according to the population described and case definition used. We aimed to define the prevalence and characteristics of reported drug allergies in hospitalised children in Singapore.

A retrospective case control study was performed through the hospital's inpatient electronic medical record (EMR) for the period of August 2002 to December 2002. The EMR was used to identify children with a previously reported ADR. The control group was randomly selected from patients hospitalised during the same period.

Of the 8437 patients hospitalised during the study period, reports of previous ADRs were found in the records of 222 patients. The mean age of the patients was 7.4 years, range 2 months to 17 years (95 percent confidence interval [CI] 6.3 - 8.4). There were 146 males and 160 Chinese. The most commonly-involved medications were betalactam antibiotics (45 percent) and non steroidal anti-inflammatory drug (18.5 percent). Compared to the control group, children with a reported ADR were more likely to be older, with a mean age of 7.4 years versus 4.6 years (p-value less than 0.001), male (odds ratio [OR] 1.7, 95 percent CI 1.2-2.4), of Chinese descent (OR 1.8, 95 percent CI 1.5-5), have an associated chronic illness (OR 3.5, 95 percent CI 2.5-5), and a diagnosis of asthma (OR 2.7, 95 percent CI 1.7-4.5).

In our paediatric inpatient population, the risk of reported ADRs increases with age, male gender, Chinese descent and the presence of chronic disease. The major drugs involved are betalactam antibiotics and non-steroidal anti inflammatory drugs.