Dapsone Topical and Phenobarbital Interaction
Drug interaction information between Dapsone Topical and Phenobarbital.
Dapsone Topical and Phenobarbital have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Dapsone Topical and Phenobarbital. 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
Both of these medicines can cause a blood condition where your red blood cells cannot carry oxygen properly. Taking them together increases the risk of this serious blood problem occurring.
What To Do
Your doctor should monitor you closely for signs of low oxygen. Seek medical help if you notice blue-colored skin, headache, or shortness of breath.
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 )] .
Dapsone Topical Also Interacts With
- Acetaminophen moderate
- Nitrofurantoin moderate
- Chloroquine moderate
- Nitroglycerin moderate
- Phenytoin moderate
Phenobarbital Also Interacts With
- Nirmatrelvir/Ritonavir major
- Ranolazine major
- Voriconazole major
- Canagliflozin moderate
- Cenobamate moderate
Frequently Asked Questions
Can I take Dapsone Topical and Phenobarbital together?
This is a moderate interaction. Your doctor should monitor you closely for signs of low oxygen. Seek medical help if you notice blue-colored skin, headache, or shortness of breath.
How serious is the interaction between Dapsone Topical and Phenobarbital?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Dapsone Topical and Phenobarbital interact?
Both of these medicines can cause a blood condition where your red blood cells cannot carry oxygen properly. Taking them together increases the risk of this serious blood problem occurring.
Understanding the Dapsone Topical and Phenobarbital Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Dapsone Topical belongs to the Topical Anti-Inflammatory class and Phenobarbital belongs to the Anticonvulsant (Barbiturate) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Both of these medicines can cause a blood condition where your red blood cells cannot carry oxygen properly. 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. Dapsone Topical has 10 total documented interactions on file in this dataset, and Phenobarbital has 59. 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 signs of low oxygen. 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 Dapsone Topical or Phenobarbital 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.