Carbamazepine and Nirmatrelvir/Ritonavir Interaction
Drug interaction information between Carbamazepine and Nirmatrelvir/Ritonavir.
Carbamazepine and Nirmatrelvir/Ritonavir have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Carbamazepine and Nirmatrelvir/Ritonavir. 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
Carbamazepine makes your body get rid of the antiviral medicine too quickly, which prevents it from working against the virus.
FDA Label Information
Anticonvulsants carbamazepine , phenobarbital, primidone, phenytoin ↓ nirmatrelvir/ritonavir Co-administration contraindicated due to potential loss of virologic response and possible resistance [see Contraindications (4) ] .
Carbamazepine Also Interacts With
- Ranolazine major
- Risperidone major
- Lithium moderate
- Apixaban moderate
- Desmopressin moderate
Nirmatrelvir/Ritonavir Also Interacts With
- Simvastatin major
- Lovastatin major
- Sildenafil major
- Rifampin major
- Lurasidone major
Frequently Asked Questions
What SPL severity band is on file for Carbamazepine + Nirmatrelvir/Ritonavir?
Compiled FDA labeling labels this pair major. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Carbamazepine has 129 labeled pairs on file vs Nirmatrelvir/Ritonavir's 86. In the major band specifically: Carbamazepine has 3 (also Ranolazine, Risperidone); Nirmatrelvir/Ritonavir has 23 (also Simvastatin, Lovastatin, Sildenafil, Rifampin).
What mechanism field is on file for Carbamazepine and Nirmatrelvir/Ritonavir?
Carbamazepine makes your body get rid of the antiviral medicine too quickly, which prevents it from working against the virus.
Nirmatrelvir/Ritonavir carries more major-labeled pairs than Carbamazepine
SPL source-record counts only. This page's band is major · classes on file: Carbamazepine (Anticonvulsant); Nirmatrelvir/Ritonavir (Antiviral (Protease Inhibitor Combination)).
Nirmatrelvir/Ritonavir has 23 major-labeled pairs vs Carbamazepine's 3.
3 major · 16 moderate · 110 minor · 129 total
- Other major peers for Carbamazepine
- Ranolazine
- Risperidone
23 major · 30 moderate · 33 minor · 86 total
- Other major peers for Nirmatrelvir/Ritonavir
- Simvastatin
- Lovastatin
- Sildenafil
- Rifampin
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.