Please check your internet connection and try again.
# Megestrol Acetate
## Overview
Megestrol acetate is a synthetic derivative of progesterone. It is available as an oral suspension and tablet.
## Primary Indications
* **Anorexia, cachexia, or unexplained significant weight loss associated with:**
* Acquired immunodeficiency syndrome (AIDS)
* Malignancy
* **Palliative treatment of advanced breast cancer**
* **Palliative treatment of advanced endometrial cancer**
## Adult Dosing
* **Anorexia/Cachexia/Weight Loss:**
* Starting dose: 400 mg to 800 mg daily.
* Can be given once daily or divided into two doses.
* Some sources suggest doses up to 1200 mg/day have been used.
* **Breast Cancer:** 160 mg daily.
* **Endometrial Cancer:** 40 mg four times daily (160 mg total daily dose).
## Pediatric Dosing
There is no established pediatric dosing for megestrol acetate. Its use in pediatric populations is generally not recommended due to potential safety concerns and lack of efficacy data.
## Dose Adjustments
* **Renal Impairment:** No specific dose adjustments are recommended.
* **Hepatic Impairment:** No specific dose adjustments are recommended, but caution is advised.
## Contraindications
* Known hypersensitivity to megestrol acetate or any component of the formulation.
* Use in pregnancy (known or suspected).
* Use in patients with a history of thromboembolic events.
## Adverse Effects
* **Common:** Weight gain, increased appetite, hypertension, hot flashes, dyspnea, rash, diarrhea, nausea, headache, abdominal pain, fatigue, edema.
* **Serious:** Thromboembolic events (deep vein thrombosis, pulmonary embolism, stroke, myocardial infarction), adrenal insufficiency (especially upon abrupt discontinuation after prolonged use), hyperglycemia, vaginal bleeding changes.
## Key Drug Interactions
* **CYP3A4 Inhibitors/Inducers:** May alter megestrol acetate concentrations.
* **Antidiabetic Agents:** Megestrol acetate may cause hyperglycemia; closer monitoring of blood glucose and potential adjustment of antidiabetic medications may be necessary.
* **Corticosteroids:** Concurrent use may increase the risk of adrenal insufficiency.
## Monitoring
* Weight and appetite.
* Blood pressure.
* Signs and symptoms of thromboembolic events.
* Blood glucose levels, especially in patients with diabetes or at risk.
* Signs of adrenal insufficiency if abrupt discontinuation is considered after prolonged high-dose therapy.
## Clinical Pearls
* Megestrol acetate is associated with significant weight gain, primarily due to increased appetite and fat deposition, not necessarily an increase in lean body mass.
* The risk of thromboembolic events and adrenal insufficiency necessitates careful patient selection and monitoring.
* Abrupt discontinuation after prolonged use, especially at higher doses, can lead to adrenal insufficiency. Tapering may be considered.
* Use in pregnancy is contraindicated. Effective non-hormonal contraception should be used by women of childbearing potential.
***
**Disclaimer:** This information is intended for healthcare professionals. It is crucial to consult the most current prescribing information and relevant clinical guidelines for complete and up-to-date details before making any treatment decisions.
