Patient/caregiver was educated on contraindications for using Tamoxifen as follows:
- Do not take tamoxifen, if you ever manifested any allergic response to intake of tamoxifen. In the event of an allergic response with this medication, report to your physician or other health care personnel, regarding your safety with continuing on intake of tamoxifen.
- Tamoxifen can interact with a number of other medications and can precipitate serious reactions. Tamoxifen intake can lead to induction of liver enzymes, which results in speeding up the metabolism, early inactivation, and removal from the body, of many drugs metabolized in the liver. This can compromise the therapeutic benefit of many drugs and consequently, might need a dose revision. If you are being newly started on tamoxifen, discuss with your physician regarding all other medications you are currently taking and their safety with tamoxifen. Also, if you have been taking tamoxifen for long, discuss with your physician regarding your history of tamoxifen intake, when you are being started on any new medication.
- Warfarin and tamoxifen are metabolized by the same enzyme systems in the liver and so, compete mutually for the enzymes. Taken concurrently, tamoxifen can take over all the enzyme for metabolism, thus slowing down metabolism of warfarin. Warfarin could remain active in the blood for unduly long time, thus increasing risk for prolonged anticoagulation. Individuals taking these two drugs together can present with hemorrhage at slightest injury and episodes of internal bleeding with bleeding per rectum and blood in the urine. If you are on blood thinners, simultaneous intake of tamoxifen could be dangerous. Check with your physician regarding your safety with these medications and an appropriate change in the plan of care.
