Home Drug Guide Megestrol Acetate

Drug Guide

Generic Name

Megestrol Acetate

Brand Names Megace, Megace ES

Classification

Therapeutic: Antineoplastic, Appetite stimulant

Pharmacological: Progestin

FDA Approved Indications

  • Advanced carcinoma of the endometrium
  • Palliative management of breast cancer
  • Cachexia or anorexia associated with AIDS or cancer

Mechanism of Action

Megestrol acetate is a synthetic progestin that acts on progesterone receptors, leading to changes in hormone levels that inhibit tumor growth and stimulate appetite.

Dosage and Administration

Adult: Palliative or cachexia: 400-800 mg daily, divided into 2-4 doses; endometrial cancer: 40 mg daily.

Pediatric: Not typically used in pediatric patients.

Geriatric: Dose adjustments based on tolerance; generally similar to adult dosing, with careful monitoring.

Renal Impairment: Use with caution; no specific dose adjustment recommended but monitor renal function.

Hepatic Impairment: Use with caution; liver function should be monitored.

Pharmacokinetics

Absorption: Well absorbed after oral administration.

Distribution: Extensively bound to plasma proteins, mainly albumin.

Metabolism: Primarily metabolized in the liver via hydroxylation and conjugation.

Excretion: Excreted mainly via urine and feces.

Half Life: Approximately 16-20 hours.

Contraindications

  • Known hypersensitivity to megestrol acetate or any component of the formulation.
  • Pregnancy (category X)

Precautions

  • Monitor for thromboembolic events, hepatic dysfunction, or adrenal insufficiency.

Adverse Reactions - Common

  • Weight gain, edema (Common)
  • Nausea, diarrhea (Common)

Adverse Reactions - Serious

  • Venous thromboembolism, heart attack, stroke (Serious but less common)
  • Hepatotoxicity, adrenal suppression (Rare)

Drug-Drug Interactions

  • Anticoagulants (may increase bleeding risk)
  • Insulin or antidiabetics (altered glucose control)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor weight, fluid retention, liver function tests, and signs of thromboembolic events.

Diagnoses:

  • Impaired nutrition related to decreased appetite or adverse effects.
  • Risk for thromboembolic event.

Implementation: Administer with food to reduce GI upset; monitor for adverse reactions.

Evaluation: Assess improvement in appetite, weight, and overall condition.

Patient/Family Teaching

  • Take medication as prescribed and do not stop abruptly.
  • Report signs of blood clots, such as swelling, pain, or shortness of breath.
  • Avoid smoking and maintain regular check-ups.

Special Considerations

Black Box Warnings:

  • Risk of thromboembolic events and fatalities; use with caution in patients with a history of thromboembolism.

Genetic Factors: N/A

Lab Test Interference: May interfere with hormone assays.

Overdose Management

Signs/Symptoms: Nausea, vomiting, dizziness, rapid weight gain, edema.

Treatment: Supportive care; consider gastric lavage or activated charcoal if ingestion is recent; symptomatic treatment.

Storage and Handling

Storage: Store at room temperature, away from moisture and light.

Stability: Stable under recommended storage conditions.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.