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Exemestane oral

Updated 2 Feb 2023 | Breast cancer


Exemestane oral formulations

Drugs List

  • AROMASIN 25mg tablets
  • exemestane 25mg tablets
  • Therapeutic Indications


    Advanced breast cancer (post-menopausal) after anti-oestrogen failed
    Postmenopausal ER+ early breast cancer following 2-3yrs tamoxifen therapy

    Adjuvant treatment of post-menopausal women with oestrogen receptor positive invasive early breast cancer, following 2-3 years of initial adjuvant tamoxifen therapy

    Advanced breast cancer in post-menopausal women, with disease progression after anti-oestrogen therapy.


    Whilst the doses stated below are those recommended by the manufacturer, local cancer network protocols for the relevant indication should be consulted.


    25mg to be taken once daily, preferably after a meal.

    In early breast cancer, continue treatment with exemestane until 5 years of combined sequential adjuvant hormonal therapy (tamoxifen followed by exemestane), or earlier if tumour relapse occurs.


    25mg to be taken once daily, preferably after a meal.

    In early breast cancer, continue treatment with exemestane until 5 years of combined sequential adjuvant hormonal therapy (tamoxifen followed by exemestane), or earlier if tumour relapse occurs.


    Children under 18 years
    Premenopausal females

    Precautions and Warnings

    Major risk factors for decreased bone mineral content
    Glucose-galactose malabsorption syndrome
    Hepatic impairment
    Hereditary fructose intolerance
    Renal impairment
    Sucrase-isomaltase insufficiency

    Advise ability to drive/operate machinery may be affected by side effects
    Treatment to be initiated and supervised by a specialist
    Some brands contain sucrose. Consult specific brand literature
    Some formulations contain hydroxybenzoate
    Consult local policy on the safe use of oral anti-cancer drugs
    Staff: Not to be handled by pregnant staff
    Define menopause biochemically if in doubt about hormonal status
    Measure bone density in at risk patients prior to therapy
    May cause loss of bone mineral density
    Potential risk of osteoporosis
    Treatment or prophylaxis of osteoporosis should be started as appropriate
    Advise patient not to take St John's wort concurrently
    Female:Contraception advised until postmenopausal status fully established

    Post-menopausal status should be ascertained by assessment of luteinizing hormone, follicle stimulating hormone and estradiol levels.

    Pregnancy and Lactation


    Exemestane is contraindicated during pregnancy.
    Exemestane should only be used in post-menopausal women. There is not sufficient data available on the use of exemestane in human pregnancies.
    Although teratogenic effects were not observed in animal studies, embryotoxicity was observed in rats and rabbits and exemestane is abortifacient in rabbits. Difficult labour, reduced foetal weights, increased foetal resorption, abortions and retarded ossification have been reported in these animal studies.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password at


    Exemestane is contraindicated for use in breastfeeding.
    It is not known whether exemestane is excreted in human breast milk. Hale considers this unlikely as steroids in general do not transfer significantly into breast milk. However, as exemestane binds irreversibly, it could suppress oestrogen levels in the infant. Hale suggests that should the patient decide to stop treatment she should wait 5 to 7 days after the last dose before breastfeeding.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Abdominal pain
    Back pain
    Cardiac failure
    Carpal tunnel syndrome
    Cholestatic hepatitis
    Gastric ulceration
    Hot flushes
    Increase in alkaline phosphatase
    Increase in serum ALT/AST
    Increased risk of fractures
    Increased sweating
    Joint disorder
    Limb pain
    Myocardial infarction
    Pain - generalised
    Peripheral oedema
    Serum bilirubin increased
    Vaginal haemorrhage
    Visual disturbances


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: June 2014

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press [Accessed on June 3, 2014].

    Martindale: The Complete Drug Reference, 37th edition (2011) ed. Sweetman, S. Pharmaceutical Press, London.

    Medications and Mothers' Milk, 14th Edition (2010) Hale, T. Hale Publishing, Amarillo, Texas.

    Summary of Product Characteristics: Aromasin. Pfizer Ltd. Revised January 2013.
    Summary of Product Characteristics: Exemestane 25mg tablets. Actavis. Revised July 2013
    Summary of Product Characteristics: Exemestane 25mg tablets. Teva. Revised May 2014

    Exemestane monograph. Hazardous Substances Data Bank (HSDB), National Library of Medicine's TOXNET system. Available from the TOXNET website: [Accessed June 3, 2014].

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    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

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