Tamoxifen + bupropion/fluoxetine/paroxetine — ↓ activation
- Tamoxifen needs CYP2D6 → endoxifen
- Strong 2D6 inhibitors reduce activation
- paroxetine/fluoxetine/bupropion
- Endoxifen concentrations can fall markedly
- Avoid strong 2D6 inhibitors when feasible
- Prefer weak/non-2D6 alternatives
Interaction at a glance
- Strong 2D6 inhibitors reduce activation
- paroxetine/fluoxetine/bupropion
- Avoid strong 2D6 inhibitors when feasible
Mechanism
- Tamoxifen needs CYP2D6 → endoxifen
Management
- Strong 2D6 inhibitors reduce activation
- paroxetine/fluoxetine/bupropion
- Endoxifen concentrations can fall markedly
Management / timing
- Avoid strong 2D6 inhibitors when feasible
- Prefer weak/non-2D6 alternatives
Self-check
- Preferred alternative for Tamoxifen + bupropion/fluoxetine/paroxetine?
Weak/non-2D6 alternatives. - How should Tamoxifen + bupropion/fluoxetine/paroxetine be managed?
Avoid strong 2D6 inhibitors when feasible. - Which metabolite does tamoxifen form through CYP2D6?
Endoxifen.
Drugs in this interaction (4)
All interaction examples · Open Tamoxifen + bupropion/fluoxetine/paroxetine — ↓ activation in the interactive console ↗