Drug General Information (ID: DDIR52ZYHK)
Drug Name			Dapsone (topical)		Drug Info		Nitrofurantoin		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiinflammatory Agents				Antiinfective Agents
Structure

Mechanism of Dapsone (topical)-Nitrofurantoin Interaction (Severity Level: Moderate)
Increased risk of methemoglobinemia Click to Show/Hide Mechanism Graph
Drug Name		Dapsone (topical)				Nitrofurantoin
Mechanism		Methemoglobinemia				Methemoglobinemia
Key Mechanism Factor 1
		Factor Name		Methemoglobinemia
		Factor Description		Methemoglobinemia is a condition in which higher than normal levels of methemoglobin are found in the blood. Methemoglobinemia is a potentially life-threatening condition in which the oxygen-carrying capacity of circulating hemoglobin is reduced due to the conversion of some or all of the four iron species from the reduced ferrous (Fe2+) state to the oxidized iron (Fe3+) state.
Mechanism Description		Increased risk of methemoglobinemia by the combination of Dapsone (topical) and Nitrofurantoin

Recommended Action
Management		Concurrent use of oral or topical dapsone with other methemoglobinemia-inducing medications should be followed with monitoring for signs and symptoms of methemoglobinemia (e.g., cyanosis, hypoxia).

References
1	Cerner Multum, Inc. "Australian Product Information.".
2	Product Information. Aczone (dapsone topical). QLT USA, Inc, Fort Collins, CO.