Estramustine


Concise Prescribing Info
Indications/Uses
Advanced prostatic carcinoma.
Dosage/Direction for Use
Adult : PO Initial: 560-840 mg/day in divided doses, adjust to 140-1,400 mg/day according to response.
Dosage Details
Oral
Advanced prostatic carcinoma
Adult: Initially, 560-840 mg daily in divided doses, adjusted to 140-1,400 mg daily according to response and GI tolerance. Assess for possible benefits of continued therapy after 30-90 days. Continue treatment as long as favourable response is maintained.
Hepatic Impairment
Severe: Contraindicated.
Contraindications
Active thrombophlebitis or thromboembolic disorders (except when the actual tumour mass is the cause of phenomenon); peptic ulcer, severe CV disease. Severe hepatic impairment. Pregnancy and lactation. Admin of live vaccines.
Special Precautions
Patient w/ history of thrombophlebitis or thromboembolic disorders esp if associated w/ estrogen therapy, CV/cerebrovascular/coronary artery disease, DM, HTN, epilepsy, migraine, metabolic bone disease associated w/ hypercalcaemia. May exacerbate pre-existing or incipient peripheral oedema or congestive heart disease. Hepatic and renal impairment.
Adverse Reactions
Oestrogenic effects (e.g. gynaecomastia, impotence, fluid retention, CV effects); GI disturbance, nausea, vomiting, hepatic dysfunction, loss of libido, leucopenia, thrombocytopenia.
Potentially Fatal: Embolism, MI, CHF, angioedema.
MonitoringParameters
Monitor BP, LFT, and Ca levels.
Drug Interactions
May increase therapeutic activity and toxicity of TCAs. Decreased absorption w/ drugs containing Ca, Mg or Al (e.g. antacids). Increased risk of angioedema w/ ACE inhibitors.
Potentially Fatal: Admin of live vaccines during treatment may result in serious infections due to immunosuppression.
Food Interaction
Milk, milk products and Ca-containing foods may impair absorption.
Lab Interference
May affect endocrine and liver function tests.
Action
Description: Estramustine is a complex of 17-β-estradiol and nitrogen mustard (normustine) linked by a carbamate ester. Estramustine and its oxidised isomer, estromustine, exert their cytotoxic effect by binding to tubulin and/or microtubule-associated proteins, thus inducing depolymerisation of microtubules, resulting in cellular metaphase arrest. Upon hydrolysis, estradiol is released causing a weak antiandrogen effect.
Pharmacokinetics:
Absorption: Incompletely (approx 75%) absorbed from the GI tract. Reduced absorption w/ food. Bioavailability: 44-75%. Time to peak plasma concentration: 2-4 hr.
Distribution: Accumulates in the prostatic carcinoma tissues and plasma.
Metabolism: Initially dephosphorylated in the GI tract. Hydrolysed and oxidised in the liver into estromustine, estradiol, and estrone.
Excretion: Mainly via faeces; urine (<1% as estradiol and estrone). Plasma half-life: 10-20 hr.
Chemical Structure

Chemical Structure Image
Estramustine

Source: National Center for Biotechnology Information. PubChem Database. Estramustine, CID=259331, https://pubchem.ncbi.nlm.nih.gov/compound/Estramustine (accessed on Jan. 22, 2020)

Storage
Store between 2-8°C.
ATC Classification
L01XX11 - estramustine ; Belongs to the class of other antineoplastic agents. Used in the treatment of cancer.
References
Anon. Estramustine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 12/07/2016.

Buckingham R (ed). Estramustine Sodium Phosphate. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com/. Accessed 12/07/2016.

Emcyt Capsule (Pharmacia and Upjohn Company). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 12/07/2016.

Joint Formulary Committee. Estramustine Phosphate. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 12/07/2016.

McEvoy GK, Snow EK, Miller J et al (eds). Estramustine Phosphate Sodium. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com/mc/ahfs/current/. Accessed 12/07/2016.

Disclaimer: This information is independently developed by MIMS based on Estramustine 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
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