Skin rashes(including isolated reports of erythema multiforme, Stevens- Johnson syndrome and bullous pemphigoid) and rare hypersensitivity reactions, including angioedema, have been reported.
A small number of patients with bony metastases have developed hypercalcaemia on initiation of therapy.
Falls in platelet count, usually to 80,000-90,000 per cu mm but occasionally lower, have been reported in patients receiving tamoxifen for breast carcinoma.
A number of cases of visual disturbance including reports ofcorneal changesand retinopathyand an increased incidence of cataracts, have been described in patients receiving tamoxifen therapy.
Uterine fibroids, endometriosis and otherendometrial changes includinghyperplasia and polyps have been reported.
Cystic ovarian swellings have occasionally been observed in pre-menopausal women receiving tamoxifen.
Leucopenia has been observed following the administration of tamoxifen, sometimes in association with anaemia and/or thrombocytopenia. Neutropenia has been reported on rare occasions; this can sometimes be severe.
Cases of deep vein thrombosis and pulmonary embolism have been reported during tamoxifen therapy (see sections 4.3, 4.4 and 4.5). When tamoxifen is used in combination with cytotoxic agents, there is an increased risk of thrombo-embolic events.
Very rarely, cases of interstitial pneumonitis have been reported.
Tamoxifen has been associated with changes in liver enzyme levels and rarely with more severe liver abnormalities including fatty liver, cholestasis and hepatitis.
Rarely, elevation of serum triglyceride levels, in some cases with pancreatitis, may be associated with the use of tamoxifen.
An increased incidence of endometrial cancer and uterine sarcoma (mostly malignant mixed Mullerian tumours) has been reported in association with tamoxifen treatment.
A known carcinogen http://cdfc.rug.ac.be/HealthRisk/cytostatics/specific_classification/IARC.htm
Fortunately for men the known cancer that tamoxifen causes in humans is Endometrial cancer (Uterus). However in animal studies it has been shown to cause Hepatocellular cancer (Liver).
: Expert Opin Drug Saf. 2002 Sep;1(3):253-67.
Breast cancer chemoprevention: risk-benefit effects of the antioestrogen tamoxifen.
Cancer Biomarkers and Prevention Group, The Biocentre, University of Leicester, University Road, Leicester, LE1 7RH, UK. firstname.lastname@example.org
The anti-oestrogen tamoxifen, which is widely used as adjuvant therapy for breast cancer, is undergoing evaluation as a chemopreventive agent in women at increased risk of developing this disease. Recent results from the National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1 prevention trial show a 49% reduction in breast cancer incidence in healthy, high-risk women. However, tamoxifen treatment has the serious side effect of increasing the incidence of endometrial cancer in women and long-term administration of tamoxifen causes hepatic tumours in rats. These liver tumours are induced via a genotoxic mechanism, but the mechanisms responsible for endometrial cancer in women are not yet known and are a focus of much debate. This review describes the findings from the chemoprevention trials and problems associated with the use of tamoxifen in this setting. The mechanism of carcinogenesis in rat liver is explained in detail and compared to the situation in humans, with a view to assessing the risks associated with tamoxifen therapy and predicting whether other anti-oestrogens might be safer alternatives.