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Pharmacologic class: Aromatase inhibitor

Therapeutic class: Antineoplastic

Pregnancy risk category D


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


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


• Hypersensitivity to drug or its components


Use cautiously in:
• severe hepatic impairment
• pregnant or breastfeeding patients
• children (safety not established).


• 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


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.


/let·ro·zole/ (let´rah-zōl) an antineoplastic used in the treatment of advanced breast cancer in postmenopausal women.


A nonsteroidal drug, C17H11N5, that inhibits the enzyme aromatase and is used to treat breast cancer in postmenopausal women.


an antineoplastic nonsteroidal aromatase inhibitor.
indication It is used to treat metastatic breast cancer in postmenopausal women.
contraindications Known hypersensitivity and pregnancy prohibit its use.
adverse effects Hepatotoxicity is a life-threatening effect of this drug. Other adverse effects include dyspnea, cough, constipation, heartburn, diarrhea, alopecia, sweating, hot flashes, hypertension, somnolence, dizziness, depression, and anxiety. Common side effects include nausea, vomiting, anorexia, rash, pruritus, headache, and lethargy.


An AROMATASE INHIBITOR drug used to treat breast cancer in menopausal women that has resisted anti-oestrogen drugs. Adjuvant treatment with letrozole in post-menopausal women with breast cancer appears to be more effective than tamoxifen in reducing the risk of recurrence. A brand name is Femara.
References in periodicals archive ?
Also measured in the study were letrozole utilization, Ibrance dose reduction and drug waste associated with dose reduction.
2% with letrozole (Femara) versus 43% with clomiphene (P = .
The goal of the current study was to determine the safety and efficacy of TMX compared to letrozole in achieving pregnancy in CC-resistant women with PCOS.
Women were randomly given clomiphene or letrozole and took the medications for up to five cycles, with increasing dosage at each cycle.
She underwent mastectomy in 2007, and had since been on AI therapy with letrozole.
The metabolism and transport effects of tamoxifen, anastrozole, exemestane, and letrozole are outlined in Table 1 (p.
Our biomarker identifies the subgroup of patients who continue to be at risk of recurrence after tamoxifen treatment and who will benefit from extended therapy with letrozole, which should allow many women to avoid unnecessary extended treatment," he said.
The per-protocol primary end point was the incidence of a musculoskeletal event, defined as worsening of pain using a simple pain intensity scale, worsening disability from musculoskeletal pain using the Health Assessment Questionnaire II, or discontinuation of letrozole because of pain at 6 months.
Everolimus in combination with exemestane for postmenopausal women with advanced breast cancer who are refractory to letrozole or anastrozole: Results of the BOLERO-2 phase III trial [Abstract 9LBA].
Sun Pharma was warned by the drug controller for promoting letrozole -- a cancer drug -- for infertility and ordered to destroy all promotional literature.
In the BIG1-98 Study, in the monotherapy arms after 5 years the 2463 women on letrozole had an 8.
To explore the impact of the selective crossover, an additional analysis was conducted censoring follow-up times at the date of crossover to letrozole for 25% of the patients in the tamoxifen arm.