Effect of N-acetylcysteine on Dapsone-Induced Methemoglobinemia

ABSTRACT

BACKGROUND: To determine whether N-acetylcysteine(NAC) reduces methemoglobin. METHOD: We carried out an in vivo experiment in rats, weighed about 300g. Each rat was ingested 200mg of dapsone(4,4'diaminodiphenyl sulphone) to induce methemo- globinemia. After 1 hour, 30 rats were received NAC 160mg(2ml) and another 30 rats, served as control, were received 2ml of normal saline orally,4 times hourly. Serum methemoglobin concentrations were checked 1,6, and 24 hours after dapsone ingestion. RESULT: The methemoglobin concentrations on each time were 27.1+/-5.8%,23.5+/-8.8%, 17.1+/-6.4%(mean+/-SD) in control group and 25.5+/-6.3%, 25.5+/-8.8%, 65.5+/-31.2%(mean+/-SD) in NAC group. There were no differences on methemoglobin concentrations at 1 and 6 hours between two groups(P>.05). At 24 hours, the methemoglobin concentrations of NAC group was significantly higher than those of control group(P<.01). CONCLUSION: NAC had no therapeutic effects on dapsone induced methemoglobinemia in this experimental setting.