Phenobarbital and Dolutegravir/Lamivudine Interaction
Drug interaction information between Phenobarbital and Dolutegravir/Lamivudine.
Phenobarbital and Dolutegravir/Lamivudine have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Phenobarbital and Dolutegravir/Lamivudine. 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
Phenobarbital speeds up the breakdown of dolutegravir in your system, which can prevent the medication from working properly.
FDA Label Information
Anticonvulsants: Oxcarbazepine Phenytoin Phenobarbital ↓Dolutegravir Avoid coadministration with DOVATO because there are insufficient data to make dosing recommendations.
Phenobarbital Also Interacts With
- Nirmatrelvir/Ritonavir major
- Ranolazine major
- Voriconazole major
- Canagliflozin moderate
- Cenobamate moderate
Dolutegravir/Lamivudine Also Interacts With
- Dofetilide major
- Metformin moderate
- Oxcarbazepine moderate
- Phenytoin moderate
- Carbamazepine minor
Frequently Asked Questions
What SPL severity band is on file for Phenobarbital + Dolutegravir/Lamivudine?
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 Dolutegravir/Lamivudine's 9. In the moderate band specifically: Phenobarbital has 13 (also Canagliflozin, Cenobamate, Clarithromycin, Dapsone Topical); Dolutegravir/Lamivudine has 4 (also Metformin, Oxcarbazepine, Phenytoin).
What mechanism field is on file for Phenobarbital and Dolutegravir/Lamivudine?
Phenobarbital speeds up the breakdown of dolutegravir in your system, which can prevent the medication from working properly.
Phenobarbital carries more major-labeled pairs than Dolutegravir/Lamivudine
SPL source-record counts only. This page's band is moderate · classes on file: Phenobarbital (Anticonvulsant (Barbiturate)); Dolutegravir/Lamivudine (Integrase Inhibitor / NRTI Combination).
Phenobarbital has 3 major-labeled pairs vs Dolutegravir/Lamivudine's 1. This page itself is in the moderate band, not the major band.
3 major · 13 moderate · 43 minor · 59 total
- Other moderate peers for Phenobarbital
- Canagliflozin
- Cenobamate
- Clarithromycin
- Dapsone Topical
1 major · 4 moderate · 4 minor · 9 total
- Other moderate peers for Dolutegravir/Lamivudine
- Metformin
- Oxcarbazepine
- Phenytoin
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.