Megace (Tablets) Instructions for Use

Instructions
Dosage forms

ATC Code

G03DB02 (Megestrol)

Active Substance

Megestrol (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Gestagen. Antineoplastic drug

Pharmacotherapeutic Group

Antineoplastic agent – progestogen

Pharmacological Action

Megace (Megestrol) is a synthetic progestogen. The exact mechanism of the antitumor effect of Megace in endometrial carcinoma remains unknown. It is believed that the action is associated with an antiluteinizing effect realized through the pituitary gland. There is an indication of a local effect of megestrol, obtained by direct administration of progestogens into the uterine cavity.

The antitumor effect of the drug in breast cancer and the mechanism by which the drug is effective in anorexia and cachexia are also unknown. Weight gain when taking megestrol acetate is associated with increased appetite and an increase in adipose tissue mass and total body mass as a whole.

Pharmacokinetics

Plasma concentrations depend on the degree of drug inactivation in the gastrointestinal tract and in the liver, which can be influenced by intestinal tract motility, intestinal microflora, concomitant use of antibiotics, body weight, diet, and the functional state of the liver.

Only about 5-8% of the administered dose of megestrol acetate accounts for metabolites.

The main routes of drug elimination from the human body are renal excretion (on average approximately 66%) and intestinal excretion (on average approximately 20% of the administered dose). The part of the administered dose that is not detected in urine and feces may be excreted through the respiratory system and accumulate in adipose tissue.

Indications

Palliative treatment of advanced breast cancer or endometrial cancer;
Treatment of anorexia or weight loss in malignant neoplasms or acquired immunodeficiency syndrome.

ICD codes

Open the list of ICD codes

ICD-10 code	Indication
C50	Malignant neoplasm of breast
C54.1	Malignant neoplasm of endometrium
R63.0	Anorexia

ICD-11 code	Indication
2C65	Hereditary breast and ovarian cancer syndrome
2C6Y	Other specified malignant neoplasms of the breast
2C6Z	Malignant neoplasms of breast, unspecified
2C76.Z	Malignant neoplasms of uterine corpus, unspecified
MG43.7	Anorexia

Dosage Regimen

The method of application and dosage regimen for a specific drug depend on its form of release and other factors. The optimal dosage regimen is determined by the doctor. It is necessary to strictly adhere to the compliance of the dosage form of a specific drug with the indications for use and dosage regimen.

Tablets

Orally. To determine the effectiveness of the drug, at least 2 months of continuous treatment are required.

Breast cancer 160 mg/day (as a single dose or in divided doses).

Endometrial cancer 80-320 mg/day (as a single dose or in divided doses).

Anorexia or weight loss a single daily dose is 400-300 mg.

Elderly patients no dose adjustment is required.

Adverse Reactions

Weight gain is a frequent effect when using Megace in patients with breast or endometrial cancer and is a consequence of increased appetite.

Thromboembolism: cases of thromboembolism, including thrombophlebitis and pulmonary embolism, have been reported.

Other side effects: nausea, vomiting, edema, and uterine bleeding not associated with menstruation are observed in approximately 1-2% of patients; reports have been made of patients experiencing dyspnea, pain, heart failure, arterial hypertension, hot flashes, mood changes, cushingoid facial signs, temporary activation of tumor development (in the absence or presence of hypercalcemia), hyperglycemia, alopecia, carpal tunnel syndrome, diarrhea, lethargy, skin rashes.

The development of pathological conditions associated with impaired functioning of the pituitary-adrenal system has been reported: glucose intolerance, the occurrence of diabetes mellitus and exacerbation of existing diabetes mellitus with decreased glucose tolerance and Cushing’s syndrome. In rare cases, clinical signs of adrenal insufficiency were observed in patients shortly after discontinuation of Megace treatment. The possibility of adrenal suppression should be considered in all patients taking the drug for a long time, as well as after drug withdrawal. In such cases, shock doses of corticosteroids may be indicated as replacement therapy.

Contraindications

As a diagnostic test for pregnancy;
Pregnancy and breastfeeding period;
Age under 18 years (efficacy and safety have not been established);
Hypersensitivity to megestrol or any other substance that is part of the drug.

With caution Megace should be used in patients with a history of thrombophlebitis.

Use in Pregnancy and Lactation

Contraindication: pregnancy and breastfeeding period.

Pediatric Use

Contraindication: age under 18 years (efficacy and safety have not been established).

Geriatric Use

Elderly patients no dose adjustment is required.

Special Precautions

Treatment with Megace should be carried out under the supervision of a specialist experienced in chemotherapeutic treatment. During therapy with Megace and for at least 3 months after, reliable methods of contraception must be used.

Overdose

In clinical studies, the drug was used in doses up to 1600 mg/day for 6 months or more. No acute toxic effects were identified.

In case of overdose, treatment should be symptomatic.

Storage Conditions

Store in a place inaccessible to children at a temperature not exceeding 25°C (77°F).

Shelf Life

Shelf life – 3 years.

Dispensing Status

The drug is dispensed by prescription.

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.

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