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MEGESTROL ACETATE

Medical Diagnosis and Drugs, Medications
MEGESTROL ACETATE
(me-jess'trole)
Megace, Megace ES
Classifications: antineoplastic; hormone; progestin;
Therapeutic: antineoplastic; progestin
Prototype: Progesterone
Pregnancy Category: X (oral suspension) and D (tablets)

Availability

40 mg/mL, 125 mg/mL suspension; 20 mg, 40 mg tablets

Action

Progestational hormone with antineoplastic properties. Mechanism of action unclear; however, an antiluteinizing effect mediated via the pituitary has been postulated.

Therapeutic Effect

Antineoplastic agent effective for treating breast, renal cell, or endometrial carcinoma. Also effective as an appetite enhancer. Has a local effect when instilled directly into the endometrial cavity.

Uses

Palliative agent for treatment of advanced carcinoma of breast or endometrium. AIDS-related wasting or cachexia.

Contraindications

Diagnostic test for pregnancy; pregnancy category X (oral suspension) and category D (tablet); lactation.

Cautious Use

Older adults; severe hepatic disease; diabetes mellitus; renal impairment; thromboembolic disease.

Route & Dosage

Palliative Treatment for Advanced Breast Cancer
Adult: PO 40 mg q.i.d.

Palliative Treatment for Advanced Endometrial Cancer
Adult: PO 40–320 mg/d in divided doses

Appetite Stimulation
Adult: PO 200 mg q6h

HIV-Related Cachexia
Adult: PO (suspension) 800 mg q.d. or 625 mg of Megace ES

Administration

Oral
  • Give with meals or food if GI distress occurs.
  • Shake oral suspension well before use.
  • Store at 15°–30° C (59°–86° F) in tightly closed container.

Adverse Effects (≥1%)

Urogenital: Vaginal bleeding. Body as a Whole: Breast tenderness, headache, increased appetite, weight gain, allergic-type reactions (including bronchial asthma). GI: Abdominal pain, nausea, vomiting. Hematologic: DVT.

Interactions

Drug: May increase levels of warfarin; may decrease renal clearance of dofetilide.

Pharmacokinetics

Absorption: Appears to be well absorbed from GI tract. Onset: Onset of objective response in breast cancer in 6–8 wk. Peak: 1–3 h. Duration: 3–12 mo. Metabolism: Completely metabolized in liver. Elimination: 57–78% of dose excreted in urine within 10 d.

Nursing Implications

Assessment & Drug Effects

  • Monitor weight periodically.
  • Notify physician if abdominal pain, headache, nausea, vomiting, or breast tenderness become pronounced.
  • Monitor for allergic reactions, including breathing distress characteristic of asthma, rash, urticaria, anaphylaxis, tachypnea, anxiety. Stop medication if they appear and notify physician.

Patient & Family Education

  • Use contraception measures during therapy for carcinoma.
  • Learn breast self-examination.
  • Learn S&S of thrombophlebitis (see Appendix F).
  • Review package insert to ensure understanding of megestrol therapy.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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