A field trial among leprosy patients in Nigeria with depot injections of dapsone and monoacetyldapsone.

In two field trials in Nigeria, 74 male and female leprosy outpatients received intra-adipose depot injections of either dapsone (DDS) or monoacetyldapsone (MADDS) at 4-week intervals. Blood samples were taken regularly and sent to Amsterdam to determine the DDS and MADDS concentrations in serum using high-pressure liquid chromatography (HPLC). The DDS injection yielded a good sustained drug release. After repeated administration accumulation occurred, demonstrated by a statistically significant increase in the area under the curve (AUC) in time: until 28 days after the first injection, the mean AUC (+/- S.D.) amounted to 19.3 +/- 5.6 mg d/l in males and 15.1 +/- 5.2 in females; after the fourth injection, 26.4 +/- 7.5 and 24.6 +/- 9.0 mg d/l, respectively (p less than 0.001). One male patient developed an abscess at the injection site; otherwise no side effects were observed. Even better sustained-release results were observed with the MADDS injection. Unfortunately, the injection caused a number of abscesses. Consequently, the DDS injection was very well received by the patients of the DDS study, while half of the patients in the MADDS study would prefer tablets to the MADDS injection. Further investigations are required to find the cause of the abscesses before one of the injections, or possibly a combination of both, could be implemented in the multi-drug treatment regimen proposed by WHO to provide a valuable tool to combat noncompliance among leprosy patients.