Please check your internet connection and try again.
# Megestrol Acetate
## Overview
Megestrol acetate is a synthetic progestin used for palliative treatment of advanced breast cancer and for the management of anorexia, cachexia, or unexplained significant weight loss in patients with acquired immunodeficiency syndrome (AIDS).
## Primary Indications
* **Advanced Breast Cancer:** Palliative treatment in postmenopausal women or in men with the disease.
* **Anorexia, Cachexia, or Significant Weight Loss in AIDS:** Management of symptoms associated with the disease.
## Adult Dosing
* **Breast Cancer:** Typically 160 mg daily. Higher doses (e.g., 400-800 mg daily) have been used but offer no proven survival advantage and increase adverse events.
* **Anorexia/Cachexia in AIDS:** Typically 400-800 mg daily. Some protocols use 125-500 mg daily.
## Pediatric Dosing
There is no established pediatric dosing for megestrol acetate. Its use in pediatric populations is not recommended.
## Dose Adjustments
* **Renal Impairment:** No specific dose adjustments are recommended.
* **Hepatic Impairment:** No specific dose adjustments are recommended, but caution is advised due to potential effects on liver function.
## Contraindications
* Known hypersensitivity to megestrol acetate or any component of the formulation.
* Pregnancy and breastfeeding.
* Known or suspected history of thromboembolic disorders.
## Adverse Effects
* **Common:** Weight gain, increased appetite, hot flashes, hypertension, nausea, vomiting, diarrhea, rash, shortness of breath, vaginal bleeding or discharge.
* **Serious:** Thromboembolic events (deep vein thrombosis, pulmonary embolism, stroke, myocardial infarction), adrenal insufficiency (especially with abrupt withdrawal after prolonged use), hyperglycemia, Cushingoid effects.
## Key Drug Interactions
* **CYP3A4 Inhibitors/Inducers:** May alter megestrol acetate concentrations.
* **Aminoglutethimide:** May decrease megestrol acetate levels.
* **Antidiabetic Agents:** May affect glycemic control.
## Monitoring
* **Weight and Appetite:** Regular monitoring for changes.
* **Blood Pressure:** Monitor for hypertension.
* **Electrolytes and Glucose:** Particularly important in patients with diabetes or at risk for adrenal insufficiency.
* **Signs of Thromboembolic Events:** Assess for leg swelling, pain, sudden shortness of breath, chest pain, or neurological deficits.
* **Adrenal Function:** Consider monitoring cortisol levels if prolonged use is anticipated or if symptoms of adrenal insufficiency (fatigue, weakness, nausea, vomiting) arise, especially during or after discontinuation.
## Clinical Pearls
* Megestrol acetate is available in oral suspension and tablet forms. The suspension may be preferred for patients experiencing nausea or dysphagia.
* Abrupt discontinuation, especially after prolonged high-dose therapy, may lead to adrenal insufficiency. Gradual tapering may be considered.
* Weight gain is a common and often desired effect in patients with cachexia, but it can also be associated with significant fluid retention and metabolic changes.
* While effective for appetite stimulation and weight gain, it does not improve survival in breast cancer and is associated with significant adverse effects, particularly at higher doses.
**Disclaimer:** This information is intended for clinical use and does not replace professional medical judgment. Always consult the most current prescribing information and relevant clinical guidelines for complete details and to confirm current recommendations.
