Nitrofurantoin and Dapsone Topical Interaction
Drug interaction information between Nitrofurantoin and Dapsone Topical.
Nitrofurantoin and Dapsone Topical have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Nitrofurantoin and Dapsone Topical. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
These medications both have the potential to change how your blood carries oxygen. Using them at the same time makes it more likely you will develop a blood problem called methemoglobinemia.
What To Do
Your doctor should monitor you closely for symptoms like headache, tiredness, or blue-tinted skin while using these drugs together.
FDA Label Information
7.4 Concomitant Use with Drugs that Induce Methemoglobinemia Concomitant use of ACZONE Gel, 7.5% with drugs that induce methemoglobinemia such as sulfonamides, acetaminophen, acetanilide, aniline dyes, benzocaine, chloroquine, dapsone, naphthalene, nitrates and nitrites, nitrofurantoin, nitroglycerin, nitroprusside, pamaquine, para‐aminosalicylic acid, phenacetin, phenobarbital, phenytoin, primaquine, and quinine may increase the risk for developing methemoglobinemia [see Warnings and Precautions ( 5.1 )] .
Nitrofurantoin Also Interacts With
- Lidocaine Topical moderate
- Probenecid minor
- Methylprednisolone minor
Dapsone Topical Also Interacts With
- Acetaminophen moderate
- Chloroquine moderate
- Nitroglycerin moderate
- Phenytoin moderate
- Phenobarbital moderate
Frequently Asked Questions
Can I take Nitrofurantoin and Dapsone Topical together?
This is a moderate interaction. Your doctor should monitor you closely for symptoms like headache, tiredness, or blue-tinted skin while using these drugs together.
How serious is the interaction between Nitrofurantoin and Dapsone Topical?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Nitrofurantoin and Dapsone Topical interact?
These medications both have the potential to change how your blood carries oxygen. Using them at the same time makes it more likely you will develop a blood problem called methemoglobinemia.
Understanding the Nitrofurantoin and Dapsone Topical Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Nitrofurantoin belongs to the Nitrofuran Antibiotic class and Dapsone Topical belongs to the Topical Anti-Inflammatory class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: These medications both have the potential to change how your blood carries oxygen. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Nitrofurantoin has 4 total documented interactions on file in this dataset, and Dapsone Topical has 10. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should monitor you closely for symptoms like headache, tiredness, or blue-tinted skin while using these drugs together. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Nitrofurantoin or Dapsone Topical based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.