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. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
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.
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
What SPL severity band is on file for Dapsone Topical + Phenobarbital?
Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Phenobarbital has 59 labeled pairs on file vs Dapsone Topical's 10. In the moderate band specifically: Dapsone Topical has 6 (also Acetaminophen, Nitrofurantoin, Chloroquine, Nitroglycerin); Phenobarbital has 13 (also Canagliflozin, Cenobamate, Clarithromycin, Dolutegravir/Lamivudine).
What mechanism field is on file for Dapsone Topical and Phenobarbital?
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.
Phenobarbital carries more major-labeled pairs than Dapsone Topical
SPL source-record counts only. This page's band is moderate · classes on file: Dapsone Topical (Topical Anti-Inflammatory); Phenobarbital (Anticonvulsant (Barbiturate)).
Phenobarbital has 3 major-labeled pairs vs Dapsone Topical's 0. This page itself is in the moderate band, not the major band.
0 major · 6 moderate · 4 minor · 10 total
- Other moderate peers for Dapsone Topical
- Acetaminophen
- Nitrofurantoin
- Chloroquine
- Nitroglycerin
3 major · 13 moderate · 43 minor · 59 total
- Other moderate peers for Phenobarbital
- Canagliflozin
- Cenobamate
- Clarithromycin
- Dolutegravir/Lamivudine
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.