MEGESTROL ACETATE- megestrol acetate tablet
Roxane Laboratories, Inc
Rx only
Description
Megestrol acetate, is a synthetic, antineoplastic and progestational drug. Megestrol acetate is a white to creamy white, crystalline powder chemically designated as pregna-4,6-diene-3,20-dione, 17-(acetyloxy)-6-methyl-. Solubility at 37�C in water is 2 mcg per mL, solubility in plasma is 24 mcg per mL. Its molecular weight is 384.51. The empirical formula is C24 H32 O4 Megestrol acetate tablets are supplied for oral administration containing 20 mg or 40 mg megestrol acetate USP and the following inactive ingredients: acacia, colloidal silicon dioxide, dibasic calcium phosphate, lactose monohydrate, magnesium stearate, and starch (corn).
Clinical Pharmacology
While the precise mechanism by which megestrol produces its antineoplastic effects against endometrial carcinoma is unknown at the present time, inhibition of pituitary gonadotrophin production and resultant decrease in estrogen secretion may be factors. There is evidence to suggest a local effect as a result of the marked changes brought about by the direct instillation of progestational agents into the endometrial cavity. The antineoplastic action of megestrol acetate on carcinoma of the breast is effected by modifying the action of other steroid hormones and by exerting a direct cytotoxic effect on tumor cells. In metastatic cancer, hormone receptors may be present in some tissues but not others. The receptor mechanism is a cyclic process whereby estrogen produced by the ovaries enters the target cell, forms a complex with cytoplasmic receptor and is transported into the cell nucleus. There it induces gene transcription and leads to the alteration of normal cell functions. Pharmacologic doses of megestrol acetate not only decrease the number of hormone-dependent human breast cancer cells but also are capable of modifying and abolishing the stimulatory effects of estrogen on these cells. It has been suggested that progestins may inhibit in one of two ways: by interfering with either the stability, availability, or turnover of the estrogen receptor complex in its interaction with genes or in conjunction with the progestin receptor complex, by interacting directly with the genome to turn off specific estrogen-responsive genes. Indications and Usage
Megestrol Acetate Tablets USP are indicated for the palliative treatment of advanced carcinoma of the breast or endometrium (i.e., recurrent, inoperable, or metastatic disease). It should not be used in lieu of currently accepted procedures such as surgery, radiation, or chemotherapy. INDICATIONS AND USAGE
Megace ES oral suspension is indicated for the treatment of anorexia, cachexia, or an unexplained significant weight loss in patients with a diagnosis of acquired immunodeficiency syndrome (AIDS). Limitations of Use
Other Treatable Causes
Therapy with megestrol acetate for weight loss should only be instituted after treatable causes of weight loss are sought and addressed. These treatable causes include possible malignancies, systemic infections, gastrointestinal disorders affecting absorption, endocrine disease, renal disease or psychiatric diseases.
Prophylactic Use
Megestrol acetate is not intended for prophylactic use to avoid weight loss.
2 DOSAGE AND ADMINISTRATION
The recommended adult initial dosage of Megace ES oral suspension is 625 mg/day (5 mL/day or one teaspoon daily). Shake the container well before using. �
This strength (125 mg/mL) is not substitutable with other strengths (e.g., 40 mg/mL). Refer to the prescribing information of the 40 mg/mL product for dosage recommendations for the 40 mg/mL strength.
3 DOSAGE FORMS AND STRENGTHS
Megace ES is a milky white, lemon-lime flavored oral suspension containing 125 mg of megestrol acetate per mL. Megace ES does not contain the same amount of megestrol acetate as Megace oral suspension or any of the other megestrol acetate oral suspensions �