Toremifene


Concise Prescribing Info
Indications/Uses
Hormone-dependent metastatic breast cancer in postmenopausal women.
Dosage/Direction for Use
Adult : PO 60 mg once daily.
Dosage Details
Oral
Metastatic breast cancer in postmenopausal women with oestrogen-receptor positive tumours
Adult: 60 mg once daily.
Hepatic Impairment
Dosage adjustments may be needed. Severe: Contraindicated.
Administration
May be taken with or without food.
Contraindications
Pre-existing endometrial hyperplasia, severe hepatic failure. History of severe thromboembolic disease. Pregnancy and lactation.
Special Precautions
Uncompensated heart failure, severe angina pectoris. Monitor for signs of hypercalcaemia for patients with bone metastases. Perform gynaecological examinations before therapy and at least once a year. Closely monitor patients at risk of endometrial cancer. Monitor CBC, serum calcium concentration and LFT periodically.
Adverse Reactions
Hot flushes, sweating, nausea, leucorrhoea, dizziness, vaginal bleeding or discharge, fatigue, headache, skin discolouration, increased weight, insomnia, constipation, dyspnoea, vomiting, vertigo, pruritus, abnormal vision, asthenia, thromboembolic events, depression, jaundice, pulmonary embolism, thrombophlebitis, loss of appetite, endometrial changes.
Overdosage
Symptoms: Anti-oestrogenic effects e.g. hot flashes; oestrogenic effects e.g. vaginal bleeding; or nervous system disorders e.g. vertigo, dizziness, ataxia and nausea. Management: Treatment is symptomatic and there is no specific antidote.
Drug Interactions
Decreased serum concentrations of toremifene with concomitant use of known CYP3A4 inducers (e.g. carbamazepine, phenobarbital, phenytoin, rifampicin). Increased serum concentrations of toremifene with erythromycin, troleandomycin, ketoconazole. Increased risk of bleeding with coumarins. Increased risk of hypercalcaemia with drugs which decrease renal calcium excretion e.g. thiazide diuretics.
Action
Description: Toremifene, a non-steroidal triphenylethylene derivative, competitively binds to oestrogen receptors on tumours and other tissue targets. It may exert oestrogenic, anti-oestrogenic, or both activities. In breast cancer it is believed to exert anti-oestrogenic effects, by competing with oestrogen for binding sites in the cancer, hence blocking the growth-stimulating effects of oestrogen in the tumour.
Pharmacokinetics:
Absorption: Well absorbed from GI tract. Peak plasma concentrations within 3 hr.
Distribution: Protein-binding: Extensive, mainly to albumin.
Metabolism: Metabolised mainly by the cytochrome P450 isoenzyme CYP3A4 to less active metabolites.
Excretion: Excreted mainly in faeces and in urine (10%) as metabolites. Undergoes enterohepatic circulation.
Storage
Store at 15-30°C (59-86°F).
Disclaimer: This information is independently developed by MIMS based on Toremifene from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
Register or sign in to continue
Asia's one-stop resource for medical news, clinical reference and education
Sign up for free
Already a member? Sign in