Mega%2525252525252525252525252525252525252525252525252525252525252525252525252525252520cv

# Megestrol Acetate ## Overview Megestrol acetate is a synthetic progestogen. ## Primary Indications * **Cachexia, anorexia, or unexplained significant weight loss:** Associated with conditions such as acquired immunodeficiency syndrome (AIDS) or cancer. * **Palliative treatment of advanced breast cancer:** Primarily in postmenopausal women or women with disease progression after prior therapy. * **Palliative treatment of advanced endometrial cancer:** Unresectable, locally advanced or metastatic disease. ## Adult Dosing * **Weight Loss/Cachexia:** * Initial dose: 800 mg daily. * Doses may be adjusted based on clinical response. Doses between 400 mg to 800 mg daily have been used. * Administer with food to improve absorption. * **Breast Cancer:** * 40 mg by mouth four times daily (160 mg daily). * Higher doses (e.g., 400-800 mg daily) have been used in some clinical trials. * **Endometrial Cancer:** * 40 mg by mouth four times daily (160 mg daily). ## Pediatric Dosing There is no established pediatric dosing. ## Dose Adjustments * **Renal Impairment:** No specific dose adjustment is recommended. * **Hepatic Impairment:** No specific dose adjustment is recommended. ## Contraindications * Known or suspected pregnancy. * Known hypersensitivity to megestrol acetate or any component of the formulation. ## Adverse Effects * **Common:** Weight gain, increased appetite, hypertension, hot flashes, dyspnea, nausea, vomiting, diarrhea, abdominal pain, rash, edema, fatigue. * **Serious:** Thromboembolic events (e.g., pulmonary embolism, deep vein thrombosis), adrenal insufficiency, hyperglycemia, new onset or worsening of diabetes mellitus, Cushing's syndrome, tumor flare. ## Key Drug Interactions * **CYP3A4 Inducers (e.g., rifampin, phenytoin, carbamazepine):** May decrease megestrol acetate concentrations. * **CYP3A4 Inhibitors (e.g., ketoconazole, itraconazole, clarithromycin):** May increase megestrol acetate concentrations. ## Monitoring * **Weight and appetite:** Regularly assess for clinical response. * **Blood pressure:** Monitor for hypertension. * **Electrolytes, glucose, and adrenal function:** Particularly in patients with risk factors for adrenal insufficiency or diabetes. * **Signs of thromboembolic events:** Monitor for symptoms like leg pain, swelling, shortness of breath, or chest pain. ## Clinical Pearls * Megestrol acetate is a potent appetite stimulant and can lead to significant weight gain. * Absorption is enhanced when taken with food. * It can cause adrenal suppression, especially with prolonged high-dose use. Tapering the dose may be necessary upon discontinuation in some patients. * Consider the risk of thromboembolic events and Cushingoid effects. *** **Disclaimer:** This information is intended for clinical decision support and does not replace the need to consult the most current prescribing information and institutional protocols. Always verify drug information with up-to-date resources before initiating or modifying therapy.