Dapsone, adverse reaction

In France, dapsone is available in combination with ferrous oxalate as Disulone (Aventis), and in 1983-98, 249 adverse reactions were reported to French pharma-covigilance centers, mainly blood dyscrasias (often neutropenia and agranulocytosis, rarely hemolysis and anemia) (11). Five patients died three of them had septicemia secondary to agranulocytosis. There were 29 cases of dapsone syndrome, 39 skin reactions, 27 cases of hver damage, and 27 cases of neurological and psychiatric adverse effects. Patients taking dapsone need to be under close medical supervision for early recognition of adverse reactions. 

Fluconazole decreases the production of the toxic metabolite of dapsone, and might therefore reduce the incidence of adverse reactions to dapsone. 

Acute generalised exanthematous pustulosis (AGEP) is a severe cutaneous adverse reaction, mostly drug related or associated with viral infections. It can also manifest as a reaction to dapsone therapy in the setting of HTV infection when used as prophylaxis for pneumocystis jirovecii pneumonia [75 ]. 

Dapsone (Avlosulfon) is a member of a class of chemical agents known as the sulfones. Dapsone is especially effective against M. leprae and is used with rifampin as the primary method of treating leprosy. Dapsone appears to exert its antibacterial effects in a manner similar to that of the sulfonamide drugs that is, dapsone impairs folic acid synthesis by competing with PABA in bacterial cells. Primary adverse effects associated with dapsone include peripheral motor weakness, hypersensitivity reactions (skin rashes, itching), fever, and blood dyscrasias, such as hemolytic anemia. 

Reilly TP, Woster PM, Svensson CK. Methemoglobin formation by hydroxylamine metabolites of sulfamethoxazole and dapsone implications for differences in adverse drug reactions. J Pharmacol Exp Ther 1999 288 951-959. 

Levamisole has been used experimentally in leprosy, particularly in combination with dapsone. This combination was used in a documented series of Indian patients, some currently lepromatous and others in the course of a leprosy reaction (1). When using doses sufficient to provide as good an effect as that obtained with clofazimine + dapsone in a comparison group, adverse effects were limited to gastrointestinal intolerance (which was usually mild), affecting only five of the 30 patients treated an incidental case developed pyrexia. 

Dapsone in combination with trimethoprim is also used for the treatment of mild to moderate first episodes of TCP, or alone for PCP prophylaxis [115, 198]. The most frequent adverse events are dose related metheglobinemia and hemolytic anemia. Since multi-drug therapy began to be used in leprosy patients, an increasing number of a rare, idiosyncratic reaction with multiorgan involvement... 

---