Femara

letrozole

Femara

Pharmacologic class: Aromatase inhibitor

Therapeutic class: Antineoplastic

Pregnancy risk category D

Action

Inhibits aromatase, an enzyme that promotes conversion of estrogen precursors to estrogen. This inhibition reduces circulating estrogen levels and stops progression of breast cancer.

Availability

Tablets: 2.5 mg

Indications and dosages

➣ Metastatic or advanced breast cancer in postmenopausal women; early breast cancer in postmenopausal women who have received 5 years of antiestrogen therapy

Adults: 2.5 mg P.O. daily

Contraindications

• Hypersensitivity to drug or its components

Precautions

Use cautiously in:

• severe hepatic impairment

• pregnant or breastfeeding patients

• children (safety not established).

Administration

• Give with or without meals.

Adverse reactions

CNS: anxiety, depression, dizziness, drowsiness, fatigue, headache, vertigo, asthenia

CV: chest pain, hypertension

EENT: blurred vision

GI: nausea, vomiting, diarrhea, constipation, abdominal pain, dyspepsia, anorexia

Metabolic: hypercalcemia

Musculoskeletal: musculoskeletal or joint pain, fractures

Respiratory: cough, dyspnea, pleural effusion

Skin: alopecia, pruritus, rash, diaphoresis

Other: hot flashes, edema, weight gain, angioedema, anaphylactic reactions

Interactions

Drug-diagnostic tests. Cholesterol, gamma-glutamyltransferase: increased levels

Patient monitoring

• Check vital signs and assess cardiovascular and respiratory status.

• Monitor renal and hepatic function, electrolyte levels, and lipid panels.

• Assess for adverse CNS effects, including depression. Institute safety measures as needed to prevent injury.

Patient teaching

• Tell patient she can take with or without food.

• Instruct patient to weigh herself regularly and report significant changes.

• Advise patient and family to watch for signs and symptoms of depression.

• Tell patient to minimize GI upset by eating small, frequent servings of healthy food and drinking plenty of fluids.

• Caution patient to avoid driving and other hazardous activities until she knows how drug affects concentration and alertness.

• Inform patient that treatment is long term. Urge her to keep follow-up appointments with prescriber.

• Tell patient to inform prescriber if she is pregnant or breastfeeding.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the tests mentioned above.

letrozole

(let-roe-zole) ,

Femara

(trade name)

Classification

Therapeutic: antineoplastics
Pharmacologic: aromatase inhibitors

Pregnancy Category: X

Indications

First-line or second-line treatment of postmenopausal women with hormone receptor positive or hormone receptor unknown advanced breast cancer.Adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer.Extended adjuvant treatment of postmenopausal early breast cancer already treated with 5 yr of tamoxifen.

Action

Inhibits the enzyme aromatase, which is partially responsible for conversion of precursors to estrogen.

Therapeutic effects

Lowers levels of circulating estrogen, which may halt progression of estrogen-sensitive breast cancer.

Decreased risk of recurrence/metastatic disease.

Pharmacokinetics

Absorption: Rapidly and completely absorbed.

Distribution: Unknown.

Metabolism and Excretion: Mostly metabolized by the liver.

Half-life: 2 days.

Time/action profile (effect on lowering of serum estradiol levels)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	2–3 days	unknown

Contraindications/Precautions

Contraindicated in: Hypersensitivity;Premenopausal women; Obstetric: Potential for fetal harm.

Use Cautiously in: Severe hepatic impairment; Lactation / Pediatric: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

• anxiety
• depression
• dizziness
• drowsiness
• fatigue
• headache
• vertigo
• weakness

Respiratory

• coughing
• dyspnea
• pleural effusion

Cardiovascular

• chest pain
• edema
• hypertension
• cerebrovascular events
• thromboembolic events

Gastrointestinal

• nausea (most frequent)
• abdominal pain
• anorexia
• constipation
• diarrhea
• dyspepsia
• vomiting

Dermatologic

• alopecia
• hot flashes
• ↑ sweating
• pruritus
• rash

Fluid and Electrolyte

• hypercalcemia

Metabolic

• hypercholesterolemia
• weight gain

Musculoskeletal

• musculoskeletal pain (most frequent)
• arthralgia
• ↓ bone density
• fractures

Interactions

Drug-Drug interaction

None significant.

Route/Dosage

Oral (Adults) 2.5 mg daily.

Hepatic Impairment

Oral (Adults) Severe hepatic impairment—2.5 mg every other day.

Availability (generic available)

Tablets: 2.5 mg

Nursing implications

Nursing assessment

• Assess patient for pain and other side effects periodically throughout therapy.
• Lab Test Considerations: May cause elevated AST, ALT, alkaline phosphatase, bilirubin, GGT and cholesterol levels.

Potential Nursing Diagnoses

Acute pain (Side Effects)

Implementation

• Do not confuse Femara (letrozole) with Femhrt (ethinyl estradiol/norethindrone).
• Oral: May be taken without regard to food.

Patient/Family Teaching

• Instruct patient to take medication as directed.
• May cause dizziness and fatigue. Caution patient to avoid driving and other activities requiring awareness until response to medication is known.
• Inform patient of potential for adverse reactions and advise her to notify health care professional if side effects are problematic.
• Caution women who are perimenopausal or who recently became menopausal to use adequate contraception during therapy; letrozole may cause fetal harm.

Evaluation/Desired Outcomes

• Slowing of disease progression in women with advanced breast cancer.
• Decreased risk of recurrence/metastatic disease.

Femara

(fə-mär′ə)

A trademark for the drug letrozole.

Femara

A brand name for LETROZOLE.