The adverse drug effects of dapsone therapy in leprosy: a systematic review

Objectives: To establish the rate of adverse drug reactions (ADR) when dapsone is given in leprosy multi-drug therapy (MDT). This paper reviews the reporting of ADRs by systematic review of the databases Ovid Medline, Ovid Embase and Global Health according to pre-specified eligibility criteria. Results: The search identified 5859 relevant citations. These publications were divided into two data sets and reviewed for their documentation of ADRs. One hundred and fourteen publications reported ADR as the primary outcome and 98 papers reported the efficacy of treatment. Of the 114 papers included, 79 were case reports, 23 retrospective studies, 7 prospective studies and 7 literature reviews. Dapsone Hypersensitivity Syndrome (DHS) was reported most frequently as an adverse effect, then anaemia (haemolytic and not otherwise specified), cutaneous eruptions, gastrointestinal disturbance and hepatitis. Eleven studies report a mean rate of DHS as 1.22% and an average fatality rate in 8 studies of 11.24%. Of the 98 papers reporting treatment efficacy, 33 papers reported ADRs to medications other than dapsone and 36 publications had no documentation of adverse effects. Conclusion: Most publications report ADRs in case reports, many from India. DHS was the most commonly reported ADR, followed by individual features of the syndrome. Many studies lack patient information with many not reporting ADRs. Our findings show that improved prospective monitoring of adverse events associated with dapsone is needed. We propose that all patients should be tested with a full blood count before starting MDT and repeated after 4-8 weeks with mandatory follow-up. This would facilitate detecting ADRs including DHS and dapsone-associated anaemias.