Megestrol Acetate
Indications
Megestrol Acetate is used for:
Contraception, Breast carcinoma, Endometrial carcinoma, Anorexia and Cachexia
Adult Dose
Oral
Palliative treatment of breast carcinoma
Adult: 40 mg 4 times daily or 160 mg once daily.
Palliative treatment of endometrial carcinoma
Adult: 40-320 mg daily in divided doses. evaluate efficacy after 2 months of treatment; up to 800 mg/day may be used
Anorexia and cachexia in patients with cancer or AIDS
Adult: Initial: 800 mg daily. Usual range: 400-800 mg daily.
Child Dose
Renal Dose
Renal impairment: Use with caution; in normal renal function, 57-78% is excreted in urine within 10 days
Administration
Should be taken with food.
Contra Indications
Pregnancy and lactation. Severe hepatic impairment.
Precautions
History of thrombophlebitis, mild to moderate hepatic impairment, risk of fluid retention, history of depression, diabetes, hypertension, renal or cardiac dysfunction.
Lactation: Not safe; do not nurse
Pregnancy-Lactation
Pregnancy
Obtain a pregnancy test in females of reproductive potential prior to initiating treatment; advise females of reproductive potential to use effective contraception while taking drug
There are no available human data to assess for any drug-associated risks of miscarriage, birth defects, or adverse maternal or fetal outcomes; advise a pregnant women of potential risk to fetus
Pregnancy testing is recommended prior to treatment
Contraception
Therapy may cause fetal harm when administered during pregnancy; advise females of reproductive potential to use effective contraception during treatment
Animal data
Based on animal data, megestrol acetate may cause fetal harm when administered to a pregnant woman and is contraindicated during pregnancy; there are no adequate animal developmental toxicity data at clinically relevant doses; pregnant rats treated with low doses resulted in reduction in fetal weight and number of live births, and feminization of male fetuses at doses below maximum recommended clinical dosing based on body surface area
Lactation
The Centers for Disease Control and Prevention recommend that HIV-1 infected mothers not breastfeed their infants to avoid risking postnatal transmission of HIV-1; the drug is present in human milk; there are no data on effects of drug on breastfed infant or on milk production; because of potential for HIV transmission and adverse effects on a breastfed infant, instruct mothers not to breastfeed if they are receiving therapy
Interactions
Concentrations of indinavir may be reduced. Possible reduced efficacy of cisplatin. Warfarin half life may be increased. Megestrol concentration may be decreased by aminoglutethimide and enzyme-inducing drugs.
Side Effects
Side effects of Megestrol Acetate :
Common
Hypertension, Insomnia, mood swings
Rash, sweating, Amenorrhea, breakthrough bleeding, change in menstrual flow, hot sweats, impotence, spotting
Diarrhea, flatulence, indigestion, nausea, vomiting, weight gain
Serious
Deep vein thrombosis (DVT), Pulmonary embolism, Thrombophlebitis, Anemia, Adrenal insufficiency
Mode of Action
Megestrol is a progestogen used as an antineplastic and appetite stimulant. The mechanism of it's antineoplastic effects is not known but may be due to inhibition of oestrogen synthesis, modulation of other steroid hormones and/or a direct cytotoxic effect on tumour cells.