Ethnic differences in adverse drug reactions to asthma medications: a systematic review

Information on ethnic diversity of adverse drug reactions (ADRs) to asthma medications is rare despite evidence suggesting higher risk for African Americans when using β2-adrenergic receptor agonists. The objectives are to investigate how ethnic background was involved in ADR assessment and to examine the relationship between ethnic background and ADRs to asthma medications.

MEDLINE was searched until March 2014. All types of studies reporting ADRs to asthma medications involving more than one ethnic group were included. Extracted information includes study designs, ethnic backgrounds, intervention, and types and severities of ADRs.

Among the selected 15 randomised clinical trials, six pooled analyses of randomized clinical trials, and five prospective observational studies, only six studies compared ADRs across different ethnic groups. The majority of the comparisons were either statistically insignificant or inconclusive.

Ethnicity was largely overlooked. Most studies neglected to report ADRs by ethnicity. Lack of consistency in defining ethnicities complicated further pooled analyses. Despite the higher prevalence of asthma among specific ethnic minority groups, few studies disaggregated information by ethnic background, and reports of ADRs to asthma medications in different ethnic groups were rare. We suggest that the inclusion of ADR analysis by different ethnic backgrounds is desirable.