megestrol

Therapeutic Classification: antineoplastics, hormones

Pharmacologic Classification: progestins

Indications ⬆ ⬇

BEERS REMS, High Alert

Palliative treatment of endometrial and breast carcinoma, either alone or with surgery or radiation (tablets only).
Treatment of anorexia, weight loss, and cachexia associated with AIDS (oral suspension only).

Action ⬆ ⬇

Antineoplastic effect may result from inhibition of pituitary function.

Therapeutic effects:

Regression of tumor.
Increased appetite and weight gain in patients with AIDS.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed from the GI tract.

Distribution: Unknown.

Protein Binding: ≥90%.

Metabolism/Excretion: Completely metabolized by the liver.

Half-Life: 38 hr (range 13–104 hr).

Time/Action Profile ⬆ ⬇

(antineoplastic activity)

ROUTE	ONSET	PEAK	DURATION
PO	wk–mos	2 mo	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Undiagnosed vaginal bleeding;
Severe hepatic impairment;
Suspension contains alcohol and should be avoided in patients with known intolerance;
OB: Pregnancy;
Lactation: Lactation.

Use Cautiously in:

Diabetes;
Mental depression;
Renal impairment;
History of thrombophlebitis;
Cardiovascular disease;
Seizures;
Rep: Women of reproductive potential;
Pedi: Safety and effectiveness not established in children;
Geri: Appears on Beers list. risk of thrombotic events and possibly death in older adults. Avoid use in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

CV: edema, THROMBOEMBOLISM

Derm: alopecia

Endo: asymptomatic adrenal suppression (chronic therapy)

GI: GI irritation

GU: vaginal bleeding

MS: carpal tunnel syndrome

Interactions ⬆ ⬇

Drug-drug:

May ↑ INR and risk of bleeding when used with warfarin.

Route/Dosage ⬆ ⬇

PO (Adults ): Breast carcinoma: 160 mg/day as a single dose or divided doses; Endometrial/ovarian carcinoma: 40–320 mg/day in divided doses; Anorexia associated with AIDS: 40 mg/mL suspension: 800 mg once daily; may ↓ to 400 mg/day after 1 mo (range 400–800 mg/day); 125 mg/mL suspension: 625 mg once daily.

Availability ⬆ ⬇

(Generic available)

Oral suspensionlemon-lime flavor: 40 mg/mL; 125 mg/mL
Tablets: 20 mg; 40 mg; 160 mg

Assessment ⬆ ⬇

Assess for swelling, pain, or tenderness in legs. Report these signs of deep vein thrombophlebitis.
Anorexia: Monitor weight, appetite, and nutritional intake in patients with AIDS.

Lab Test Considerations:

Verify negative pregnancy test before starting therapy.

Implementation ⬆ ⬇

Because of high dose, suspension is most convenient form for patients with AIDS.
PO: May be administered with meals if GI irritation becomes a problem.
- Shake suspension well before administering.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take megestrol as directed; do not skip or double up on missed doses. Missed doses may be taken as long as not right before next dose. Gradually decrease dose prior to discontinuation.
Advise patient to report to health care professional any unusual vaginal bleeding or signs of deep vein thrombophlebitis.
Discuss with patient the possibility of hair loss. Explore methods of coping.
Rep: May cause fetal harm. Advise females of reproductive potential to use effective contraception during and for at least 4 mo after therapy is completed. Advise patient to notify health care professional immediately if pregnancy is planned or suspected, and to avoid breastfeeding during therapy.

Evaluation/Desired Outcomes ⬆ ⬇

Slowing or arresting the spread of endometrial or breast malignancy. Therapeutic effects usually occur within 2 mo of initiating therapy.
Increased appetite and weight gain in patients with AIDS.

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Pronunciation ⬇

Classifications ⬆ ⬇