Nirmatrelvir/Ritonavir and Vasopressin Interaction
Drug interaction information between Nirmatrelvir/Ritonavir and Vasopressin.
Nirmatrelvir/Ritonavir and Vasopressin have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Nirmatrelvir/Ritonavir and Vasopressin. 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
This combination causes tolvaptan levels to rise because the body cannot get rid of it fast enough. This can lead to severe fluid loss and high potassium levels.
FDA Label Information
Vasopressin receptor antagonists tolvaptan ↑ tolvaptan Co-administration contraindicated due to potential for dehydration, hypovolemia and hyperkalemia [see Contraindications (4) ] .
Nirmatrelvir/Ritonavir Also Interacts With
- Simvastatin major
- Lovastatin major
- Sildenafil major
- Carbamazepine major
- Rifampin major
Vasopressin Also Interacts With
- Itraconazole moderate
- Lithium minor
- Enalapril minor
- Haloperidol minor
- Clozapine minor
Frequently Asked Questions
What SPL severity band is on file for Nirmatrelvir/Ritonavir + Vasopressin?
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?
Nirmatrelvir/Ritonavir has 86 labeled pairs on file vs Vasopressin's 9. In the major band specifically: Nirmatrelvir/Ritonavir has 23 (also Simvastatin, Lovastatin, Sildenafil, Carbamazepine); Vasopressin has 1.
What mechanism field is on file for Nirmatrelvir/Ritonavir and Vasopressin?
This combination causes tolvaptan levels to rise because the body cannot get rid of it fast enough. This can lead to severe fluid loss and high potassium levels.
Nirmatrelvir/Ritonavir carries more major-labeled pairs than Vasopressin
SPL source-record counts only. This page's band is major · classes on file: Nirmatrelvir/Ritonavir (Antiviral (Protease Inhibitor Combination)); Vasopressin (Vasopressin Receptor Agonist).
Nirmatrelvir/Ritonavir has 23 major-labeled pairs vs Vasopressin's 1.
23 major · 30 moderate · 33 minor · 86 total
- Other major peers for Nirmatrelvir/Ritonavir
- Simvastatin
- Lovastatin
- Sildenafil
- Carbamazepine
1 major · 1 moderate · 7 minor · 9 total
Vasopressin has no other major-band peer in this dataset besides Nirmatrelvir/Ritonavir.
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.