The following is information on contraindications to the use of tamoxifen in general, pregnancy, breastfeeding and children. Please note that the contraindications may vary depending on the dosage form of a drug (eg tablet, syringe, ointment).
When should Tamoxifen not be used?
Tamoxifen should not be used in case of hypersensitivity to the active substance.
Tamaxifen is only to be used under strict medical benefit-risk consideration and regular controls
- in case of a lack of white blood cells or platelets
- if the calcium concentration in the blood is too high
- Exceptional monthly bleeding and postmenopausal bleeding because there is an increased risk of uterine cancer
The human endowment of enzymes is very different. Some patients have less of the enzyme CYP2D6, which transforms tamoxifen in the body into the actual active ingredient endoxifen. This may explain why similar doses often inhibit cancer growth differently. To what extent the doctor has to adjust the dose in such cases is still under investigation.
What should you watch out for during pregnancy and lactation?
Tamoxifen should not be used during a link = “A” pregnancy. Animal studies have shown malformations. Therefore, pregnancy should be ruled out before treatment with tamoxifen and safe contraception must be ensured during treatment.
Tamoxifen inhibits milk production in humans. Milk production does not restart even after the end of therapy. Breastfeeding is therefore not possible during treatment with the active ingredient. So either breastfeeding must be omitted or tamoxifen can not be used for the duration of the lactation period.
What should be considered in children?
Tamoxifen should not be used in children.
Warnings and Precautions
- Changes in vision should be clarified by ophthalmological examination.
- If you have vaginal bleeding after menopause and other vague bleeding, check with a gynecologist immediately.
- As the duration of therapy increases, the risk of uterine cancer increases.
- During the treatment with the drug should be a regular medical check-up of the blood count.
- Treated patients should be screened at least annually by the gynecologist for uterine changes.
- Treatment with the drug may result in positive drug test results.
- The medicine should be used only by physicians experienced in the treatment of cancer.
- If the drug provokes fatigue, drowsiness, and vision impairment, driving machinery and driving during treatment can be dangerous.
Sometimes medications release allergic reactions.
If you notice any signs of allergic reaction, tell your doctor or pharmacist immediately.