Can dapsone (Avlosulfon) induce pleuritis?/nBackground: A 65-year-old man has suffered from dermati

Fråga: Can dapsone (Avlosulfon) induce pleuritis? Background: A 65-year-old man has suffered from dermatitis herpetiformis for 30 years and has been treated with dapsone for several years. Half an year ago an unilateral pleuritis was diagnosed. The etiology is unknown.

Sammanfattning: Chronic dapsone therapy is not known to induce pleural changes.

Svar: Dapsone (avlosulfon, 4,4´-diaminodiphenylsulfone), an antileprotic drug, is not registered in Sweden but is relatively widely used in dermatitis herpetiformis. The mechanism of action is not known but may be related to inhibition of the myeloperoxide-H2O2 iodide system (1). Dapsone is extensively metabolized, both by acetylation and hydroxylation. The former shows a genetically determined bimodal distribution, and patients can be divided into slow and fast acetylators. There is, however, no clear relationship between acetylation capacity and the clinical response, but hematologic side effects (hemolytic anemia, methemoglobinemia) may be more common in slow acetylators (2).

We did not find any information about dapsone-induced pleural changes. In the Swedish Adverse Drug Reactions Advisory Committee (SADRAC), there were no adverse lung reactions associated with dapsone therapy (3). The WHO database did not contain any reports of pleuritis associated with dapsone (4). A case report of pulmonary eosinophilia (Loeffler´s syndrome) was, however, recently reported (5). Interestingly, in another case report, sulfasalazine therapy was associated with systemic lupus erythematosus with bilateral pleural effusions (6). Dapsone is chemically related to sulfonamides.

If other reasons for pleuritis are not found the case should be reported to the regional center of the SADRAC.