This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo

Megestrol acetate oral


Oral formulations containing megestrol acetate

Drugs List

  • MEGACE 160mg tablets
  • megestrol 160mg tablets
  • Therapeutic Indications


    Carcinoma of breast

    Unlicensed Uses

    Carcinoma - endometrium
    Renal cell carcinoma


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


    Breast Cancer
    The recommended dose is 160 mg megestrol acetate once daily.

    At least two months of continuous treatment is considered an adequate period for determining the efficacy of megestrol acetate.


    Children under 18 years

    Precautions and Warnings

    Disorders aggravated by fluid retention
    Predisposition to venous thromboembolism
    Diabetes mellitus
    Glucose-galactose malabsorption syndrome
    History of depression
    History of hepatic neoplasm
    Lactose intolerance
    Renal impairment
    Severe arterial disorder
    Severe hepatic impairment
    Undiagnosed gynaecological haemorrhage

    May decrease glucose tolerance in patients with diabetes mellitus
    Treatment to be prescribed under the supervision of a specialist
    Contains lactose
    Monitor renal function in elderly patients
    Prolonged or high dose may lead to adrenal suppression
    Female: Ensure adequate contraception during treatment

    Megestrol acetate may cause adrenal suppression. Replacement treatment with glucocorticoids during periods of stress may be required.

    Use in elderly patients should be cautious due to the increased likelihood of decreased hepatic, renal or cardiac function, and the concomitant use of other therapies.

    Megestrol acetate is primarily excreted by the kidney and thus the risk of reactions may be greater in patients with impaired renal function.

    Pregnancy and Lactation


    Megestrol acetate is contraindicated during pregnancy.

    There are reports of an association between intrauterine exposure to progestogens during the first trimester of pregnancy and genital abnormalities in male and female foetuses. The risk of hypospadias in male foetuses may be doubled by exposure to progestational drugs when compared to the general population.

    If a patient is exposed to megestrol acetate during the first 4 months of pregnancy or if she becomes pregnant whilst taking megestrol acetate she should be advised on the potential risks to the foetus.

    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 to 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 on the internet ( ) or if this is unavailable at the backup site ( ).


    Megestrol acetate is contraindicated in breastfeeding.

    Due to the potential for adverse effects on the nursing infant, breastfeeding should be discontinued during treatment with megestrol acetate.

    As megestrol acetate is a progesterone derivative, its effects are probably similar to other progesterone therapies, which includes the suppression of milk production. It is suggested that very little natural progesterone is available to the infant via milk and so it may be true that the direct effects of progesterone treatment on the infant will be limited (Hale, 2014).

    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

    Adrenal suppression
    Altered glucose tolerance
    Cardiac failure
    Carpal tunnel syndrome
    Cushing's syndrome
    Cushingoid facies
    Diabetes mellitus
    Erectile dysfunction
    Exacerbation of diabetes
    Hot flushes
    Impaired adrenal function
    Increased appetite
    Mood changes
    Pulmonary embolism
    Tumour flare
    Urinary frequency
    Weight changes


    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: October 2016

    Reference Sources

    Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. Accessed on 17 October 2016.

    Medications and Mothers' Milk, Sixteenth Edition (2014) Hale, T and Rowe, H, Hale Publishing, Plano, Texas.

    Summary of Product Characteristics: Megace 160 mg Tablets. Swedish Orphan Biovitrum Ltd. Revised February 2015.

    The Norwegian Porphyria Centre (NAPOS).
    Available at:
    Last revised: 14 July 2010
    Last accessed: 27 October 2016

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

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

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.