Tamoxifen and Desvenlafaxine Interaction
Drug interaction information between Tamoxifen and Desvenlafaxine.
Tamoxifen and Desvenlafaxine have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Tamoxifen and Desvenlafaxine. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Desvenlafaxine does not change the way the body breaks down tamoxifen.
What To Do
These medications can be used together without changing your dosage.
FDA Label Information
Examples desipramine, atomoxetine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine 7.2 Drugs Having No Clinically Important Interactions with PRISTIQ Based on pharmacokinetic studies, no dosage adjustment is required for drugs that are mainly metabolized by CYP3A4 (e.g., midazolam), or for drugs that are metabolized by both CYP2D6 and CYP3A4 (e.g., tamoxifen, aripiprazole), when administered concomitantly with PRISTIQ [see Clinical Pharmacology (12.3) ].
Tamoxifen Also Interacts With
- Warfarin major
- Anastrozole major
- Letrozole moderate
- Bupropion minor
- Letrozole (Fertility) minor
Desvenlafaxine Also Interacts With
- Aspirin moderate
- Linezolid moderate
- Phenelzine moderate
- Tranylcypromine moderate
- Selegiline moderate
Frequently Asked Questions
Can I take Tamoxifen and Desvenlafaxine together?
This is a minor interaction. These medications can be used together without changing your dosage.
How serious is the interaction between Tamoxifen and Desvenlafaxine?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Tamoxifen and Desvenlafaxine interact?
Desvenlafaxine does not change the way the body breaks down tamoxifen.
Understanding the Tamoxifen and Desvenlafaxine Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Tamoxifen belongs to the Selective Estrogen Receptor Modulator (SERM) class and Desvenlafaxine belongs to the Serotonin-Norepinephrine Reuptake Inhibitor (SNRI) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Desvenlafaxine does not change the way the body breaks down tamoxifen. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Tamoxifen has 10 total documented interactions on file in this dataset, and Desvenlafaxine has 19. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: These medications can be used together without changing your dosage. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Tamoxifen or Desvenlafaxine based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.