Many different drugs are used to treat depression. One family of drugs that are often used are the SSRIs (selective serotonin reuptake inhibitors). These drugs may also be used to treat hot flushes caused by hormonal treatments like tamoxifen.
Some studies have looked at the effect of taking an SSRI drug at the same time as tamoxifen. These show that taking an SSRI can change the way the body handles tamoxifen (tamoxifen metabolism).
Not all SSRIs affect tamoxifen metabolism equally. Paroxetine (Seroxat) and fluoxetine (Prozac) have the strongest effect, and the drugs citalopram (Cipramil) and venlafaxine (Efexor) have a weaker effect.
No one is sure if these changes in tamoxifen metabolism affect how well it works as a breast cancer treatment. We don’t know whether taking an SSRI makes tamoxifen less effective. More studies are being done to look into this.
If you are taking an SSRI and are also taking tamoxifen then have a chat with your doctor. They will be able to talk through the best options for you. These may include:
- Continuing with your present treatment
- Changing to one of the SSRI tablets that seems to have smaller effect on tamoxifen metabolism
- Stopping the SSRI and taking another treatment for depression or hormonal symptoms
- Changing to another hormone treatment not affected by SSRIs and continuing with the anti-depressant.
Reference
Jin Y et al CYP2D6 Genotype, Antidepressant Use, and Tamoxifen Metabolism During Adjuvant Breast Cancer Treatment. J Natl Cancer Inst 2005; 97: 30-39.