Meganor® 160 Tablet: Each film-coated tablet contains Megestrol Acetate USP 160 mg.
Meganor® is a preparation of Megestrol Acetate. The precise mechanism of action by which Megestrol Acetate produces its antineoplastic effects is unknown at present. Pharmacologic doses of Megestrol Acetate exerted a direct cytotoxic effect on human breast cancer cells in vitro and proved capable of modifying and abolishing the stimulatory effects of estrogen on breast cancer cell lines. Megestrol Acetate interacts with progesterone receptors to stimulate cell maturation through a progestin-inducing mechanism. It has also been shown to have certain androgenic properties and may also modify glucocorticoid action by binding to the glucocorticoid receptor.
Pharmacokinetics:
In 24 healthy male volunteers (age 19-44 years) who received 160 mg of Megestrol Acetate given as a 40 mg q.i.d. regimen, the oral absorption of Megestrol Acetate appeared to be variable. Peak drug levels for the first 40 mg dose ranged from 10 to 56 ng/mL (mean 27.6 ng/mL) and the times to peak concentrations ranged from 1.0 to 3.0 hours (mean 2.2 hours). Plasma elimination half-life ranged from 9.9 to 104.9 hours (mean 34.2 hours). The steady state plasma concentrations for a 40 mg q.i.d. regimen have not been established. Estimates of plasma levels of Megestrol Acetate are dependent on the measurement method used. Plasma levels depend on intestinal and hepatic inactivation of the drug, which may be affected by intestinal tract mobility, intestinal bacteria, concomitant antibiotic administration, body weight, diet and hepatic function.
Possible interactions of Megestrol Acetate with concomitant medications have not been investigated.
The use of progestational agents during the first four months of pregnancy is not recommended. There is no adequate evidence that such use is effective and there is evidence of potential harm to the fetus when such drugs are given during the first four months of pregnancy. Furthermore, in the vast majority of women, the cause of abortion is a defective ovum, which progestational agents could not be expected to influence. In addition, the use of progestational agents, with their uterine-relaxant properties, in patients with fertilized defective ova may cause a delay in spontaneous abortion.
Because many drugs are excreted in human breast milk and because of the potential for adverse reactions in nursing infants, nursing should be discontinued when receiving Megestrol Acetate therapy.
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, systematic infections, gastrointestinal disorders affecting absorption, endocrine disease and renal or psychiatric disease. Use Megestrol Acetate with caution in patients with a history of thrombophlebitis. Close, customary surveillance is indicated as in any patient being treated for recurrent or metastatic cancer. Patients receiving large doses of progestational agents such as Megestrol Acetate continuously for prolonged periods should be observed closely for possible adrenal cortical suppression.
Store below 30°C temperature, keep away from light and wet place. Keep out of reach of children.