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).
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	week–months	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 thromboembolism;
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: DEEP VEIN THROMBOSIS (DVT), edema

Derm: alopecia

Endo: asymptomatic adrenal suppression (chronic therapy)

GI: GI irritation

GU: vaginal bleeding

MS: carpal tunnel syndrome

Resp: PULMONARY EMBOLISM (PE)

Interactions ⬆ ⬇

Drug-drug:

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

Route/Dosage ⬆ ⬇

Breast Carcinoma

PO (Adults ): 160 mg/day as a single dose or divided doses.

Endometrial Carcinoma

PO (Adults ): 40–320 mg/day in divided dose.

Anorexia Associated With AIDS

PO (Adults ): 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 ⬆ ⬇

Monitor for signs and symptoms of venous thromboembolism such as PE (chest pain, dyspnea, tachycardia) or DVT (calf pain or tenderness, lower extremity edema, localized warmth or erythema). Report if suspected.
Anorexia: Monitor weight, appetite, and nutritional intake in patients with AIDS.

Lab Test Considerations:

Verify negative pregnancy test before starting therapy.

Implementation ⬆ ⬇

When cutting, crushing, or handling tablets, wear double chemotherapy gloves, protective gown, and hair and shoe covers. Prepare in a ventilated engineering control, if possible, and consider crushing tablets in a pill pouch. Use respiratory (N95) protection and eye and face protection, if not prepared in a ventilated engineering control. During administration, wear double chemotherapy gloves and protective gown when handling uncoated, cut, or crushed tablets. Eye/face protection is needed if there is risk of patient vomiting or spitting up. Single chemotherapy gloves are appropriate if handling and administering intact tablets from a unit-dose package.
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. Suspension is compatible to mix with water, apple juice, orange juice, or Sustacal H.C. for immediate consumption.

Patient/Family Teaching ⬆ ⬇

Explain the purpose and side effects of megestrol. Instruct patient to take 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 read Patient Information before starting and with each Rx refill in case of changes.
Advise patient to report to health care provider any unusual vaginal bleeding or signs of DVT or PE.
Discuss with patient the possibility of hair loss. Explore methods of coping.
Rep: May cause fetal harm. Advise women of reproductive potential to use effective contraception during and for ≥4 mo after therapy is completed. Advise patient to notify health care provider 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 ⬆ ⬇