Tamoxifen Citrate has 12 known drug interactions based on U.S. FDA drug labeling data. Of these, 3 are contraindicated combinations that should be avoided entirely. 3 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Anastrozole, Letrozole, Rifampin. Patients taking Tamoxifen Citrate should inform their healthcare provider of all current medications — including over-the-counter drugs and supplements — to avoid potentially harmful combinations. Data sourced from OpenFDA and the NIH National Library of Medicine.
- Total
- 12
- Contraindicated
- 3
- Major
- 3
- Moderate
- 5
Contraindicated (3)
- Tamoxifen Citrate + Anastrozole— Tamoxifen should not be administered with anastrozole based on clinical and pharmacokinetic results from adjuvant trial.
- Tamoxifen Citrate + Letrozole— Concomitant use not recommended. Tamoxifen reduced letrozole plasma concentration by 38%, and efficacy of combination in…
- Tamoxifen Citrate + Rifampin— Strong CYP3A4 inducers should not be used with tamoxifen. Rifampin reduces tamoxifen AUC and Cmax.
Major (3)
- Tamoxifen Citrate + Cytotoxic Agents— Increased risk of thromboembolic events when used in combination with tamoxifen.
- Tamoxifen Citrate + Oral Anticoagulants— Significant increase in anticoagulant effect may occur; careful monitoring of prothrombin time is recommended.
- Tamoxifen Citrate + Warfarin— Marked increase in anticoagulant effect may occur. Closely monitor coagulation indices in patients taking tamoxifen for …
Moderate (5)
- Tamoxifen Citrate + Aminoglutethimide— Reduces tamoxifen and N-desmethyl tamoxifen plasma concentrations.
- Tamoxifen Citrate + Bromocriptine— Concomitant bromocriptine therapy elevates serum tamoxifen and N-desmethyl tamoxifen concentrations.
- Tamoxifen Citrate + Medroxyprogesterone— Reduces plasma concentrations of N-desmethyl tamoxifen, but not tamoxifen itself.
- Tamoxifen Citrate + Paroxetine— Impact on tamoxifen efficacy not well established. Strong CYP2D6 inhibitors may reduce tamoxifen efficacy by reducing po…
- Tamoxifen Citrate + Phenobarbital— One patient exhibited lower steady state serum level of tamoxifen; clinical significance not known.