Nirmatrelvir/Ritonavir and Tamsulosin Interaction
Drug interaction information between Nirmatrelvir/Ritonavir and Tamsulosin.
Nirmatrelvir/Ritonavir and Tamsulosin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Nirmatrelvir/Ritonavir and Tamsulosin. 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 treatment stops your body from breaking down tamsulosin. This causes the drug to stay in your system longer and reach levels that could be harmful.
FDA Label Information
Alpha 1- adrenoreceptor antagonist tamsulosin ↑ tamsulosin Avoid concomitant use with PAXLOVID.
Nirmatrelvir/Ritonavir Also Interacts With
- Simvastatin major
- Lovastatin major
- Sildenafil major
- Carbamazepine major
- Rifampin major
Tamsulosin Also Interacts With
- Furosemide major
- Paroxetine moderate
- Warfarin moderate
- Erythromycin moderate
- Terbinafine moderate
Frequently Asked Questions
What SPL severity band is on file for Nirmatrelvir/Ritonavir + Tamsulosin?
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?
Nirmatrelvir/Ritonavir has 86 labeled pairs on file vs Tamsulosin's 18. In the moderate band specifically: Nirmatrelvir/Ritonavir has 30 (also Amlodipine, Fluticasone, Apixaban, Clopidogrel); Tamsulosin has 8 (also Paroxetine, Warfarin, Erythromycin, Terbinafine).
What mechanism field is on file for Nirmatrelvir/Ritonavir and Tamsulosin?
This treatment stops your body from breaking down tamsulosin. This causes the drug to stay in your system longer and reach levels that could be harmful.
Nirmatrelvir/Ritonavir carries more major-labeled pairs than Tamsulosin
SPL source-record counts only. This page's band is moderate · classes on file: Nirmatrelvir/Ritonavir (Antiviral (Protease Inhibitor Combination)); Tamsulosin (Alpha-1 Adrenergic Blocker).
Nirmatrelvir/Ritonavir has 23 major-labeled pairs vs Tamsulosin's 1. This page itself is in the moderate band, not the major band.
23 major · 30 moderate · 33 minor · 86 total
- Other moderate peers for Nirmatrelvir/Ritonavir
- Amlodipine
- Fluticasone
- Apixaban
- Clopidogrel
1 major · 8 moderate · 9 minor · 18 total
- Other moderate peers for Tamsulosin
- Paroxetine
- Warfarin
- Erythromycin
- Terbinafine
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.