Megestrol Acetate
Pronouncation: (me-JES-trole AS-eh-tate)Class: Progestin
Trade Names:
Megace
- Suspension 40 mg/mL
Trade Names:
Megace ES
- Suspension 125 mg/mL
Trade Names:
Megestrol
- Tablets 20 mg
- Tablets 40 mg
Linmegestrol (Canada)
Megace OS (Canada)
Nu-Megestrol (Canada)
Pharmacology
Feedback for Megestrol Acetate
|
Inhibits secretion of pituitary gonadotropins with a resultant decrease in estrogen secretion; exerts a direct cytotoxic effect on tumor cells; mechanism of effect on anorexia and cachexia is unknown.
Pharmacokinetics
Absorption
C max is 10 to 56 ng/mL; T max is 1 to 3 h for tablets. C max is approximately 753 ng/mL, and T max is approximately 5 h for suspension.
Metabolism
The megestrol acetate metabolites are negligible.
Elimination
The major route for elimination is urine; minor routes are feces and respiratory, as CO 2 . The t ½ is 13 to 104.9 h (mean, 34.2 h) for tablets.
Indications and Usage
Oral suspensionTreatment of anorexia, cachexia, or an unexplained weight loss in patients diagnosed with AIDS.
TabletsPalliative treatment of advanced inoperable, recurrent, or metastatic carcinoma of breast or endometrium.
Contraindications
Hypersensitivity to progestins or any component of these formulations; known or suspected pregnancy (suspension).
Dosage and Administration
Breast CancerAdults
PO 40 mg 4 times daily.
Endometrial CancerAdults
PO 40 to 320 mg/day in divided doses.
Anorexia, Cachexia, Unexplained Weight Loss in AIDS patientsAdults
PO 800 mg/day. PO 625 mg/day ( Megace ES ).
General Advice
- Shake suspension well before using.
Storage/Stability
Store tablet in dry, cool place at room temperature (59° to 86°F).
Store suspension between 59° and 77°F. Dispense in tight container. Protect from light.
Drug Interactions
DofetilideElevated dofetilide plasma concentrations may occur. Do not use concurrently.
IndinavirCoadministration results in a significant decrease in C max and AUC of indinavir.
Laboratory Test Interactions
None well documented.
Adverse Reactions
Cardiovascular
Hypertension (8%); cardiomyopathy, palpitation (1% to 3%); heart failure, thromboembolic phenomena, including pulmonary embolism and thrombophlebitis.
CNS
Headache (10%); asthenia (6%); abnormal thinking, confusion, convulsion, depression, hyperesthesia, neuropathy, paresthesia (1% to 3%); hot flashes, lethargy, malaise, mood changes.
Dermatologic
Rash (2%); alopecia, pruritus, skin disorder, sweating, vesiculobullous rash (2%).
EENT
Amblyopia, pharyngitis (2%).
GI
Diarrhea (15%); flatulence (10%); vomiting (6%); nausea (5%); dyspepsia (4%); abdominal pain or discomfort, constipation, dry mouth, increased salivation, oral moniliasis (1% to 3%).
Genitourinary
Impotence (14%); decreased libido (5%); urinary frequency (2%); albuminemia, breakthrough bleeding, gynecomastia, urinary incontinence, UTI (1% to 3%).
Hematologic-Lymphatic
Leukopenia (1% to 3%).
Hepatic
Anemia (5%); hepatomegaly (1% to 3%).
Metabolic-Nutritional
Hyperglycemia (6%); increased LDH, peripheral edema (1% to 3%); glucose intolerance.
Respiratory
Pneumonia (2%); cough, dyspnea, lung disorder (1% to 3%).
Miscellaneous
Fever, pain (6%); chest pain, edema, herpes, infection, moniliasis, sarcoma (1% to 3%); carpal tunnel syndrome, increased appetite, tumor flare, weight gain.
Precautions
Pregnancy
TabletsCategory D .
SuspensionCategory X .
Lactation
Excreted in breast milk.
Children
Safety and efficacy not established.
Elderly
Use with caution, usually starting at the low end of the dosage range because of the greater frequency of decreased cardiac, hepatic, or renal function, and concomitant diseases or other drug therapy.
Adrenal insufficiency
Adrenal insufficiency may occur in patients receiving or being withdrawn from chronic megestrol acetate therapy.
Cushing syndrome
Has occurred.
Diabetes mellitus
New onset diabetes mellitus and exacerbation of preexisting diabetes mellitus has occurred.
Thromboembolic disease
Use with caution in patients with history of thromboembolic disease.
Overdosage
Symptoms
No data.
Patient Information
- Explain potential significance of breakthrough bleeding, irregular menstrual cycles, and possible lack of menstrual cycle. Tell patient to notify health care provider of heavy or continuous menstrual flow.
- Encourage patients with diabetes to monitor blood glucose more frequently until effect on diabetes control has been determined.
- Instruct patient to report these symptoms to health care provider: chest pain; clay-colored stools; dark urine; dyspnea; edema; jaundice; numbness in extremities; pain in calves of legs with redness, warmth, and swelling; sudden severe headache; visual disturbances.
- Inform patient about the product differences in dosages. Depending on the indications for use, the various oral suspensions contain different amounts of megestrol acetate in 5 mL.
- Instruct patient to report any adverse reactions.
- Advise women of childbearing potential to use contraception and avoid becoming pregnant while taking this drug.
![]() |
Link to this Page | ![]() |
Printable Version | ![]() |
Email Page | ![]() | Add to my drug list |
More Megestrol Acetate resources:
Megace - Includes detailed dosage instructions.
Megestrol Acetate Drug Interactions
Weight Loss, Endometrial Cancer, Breast Cancer -- Palliative, Abnormal Uterine Bleeding, Anorexia, Cachexia













