Names and pronunciation
(let′roe-zole) Femara
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Individual generic drug information
Extracted information for letrozole only.
(let′roe-zole) Femara
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Func. class.: Antineoplastic, non- steroidal aromatase inhibitor
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Do not confuse: Femara/Femhrt
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ACTION: Binds to the heme group of aromatase; inhibits conversion of andro- gens to estrogens to reduce plasma estrogen levels
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USES: Early, advanced, or metastatic breast cancer in postmenopausal women who are hormone receptor positive
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Unlabeled uses: Infertility, ovarian can- cer, idiopathic short stature, constitutional delayed puberty
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Extracted information for letrozole only.
CONTRAINDICATIONS: Preg- nancy, premenopausal females, hyper- sensitivity Precautions: Respiratory/hepatic dis- ease, osteoporosis
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SIDE EFFECTS CNS: Headache, lethargy, somnolence, dizziness, depression, anxiety CV: Angina, MI, CVA, thromboembolic events, hypertension, peripheral edema GI: Nausea, vomiting, anorexia, consti- pation, heartburn, diarrhea GU: Endometrial cancer, vaginal bleeding, endometrial proliferation disorders INTEG: Rash, pruritus, alopecia, sweating MISC: Hot flashes, night sweats, second malignancies, anaphylaxis, angioedema, infections MS: Arthralgia, arthritis, bone fracture, myalgia, osteoporosis RESP: Dyspnea, cough
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INTERACTIONS Decrease: letrozole effect—estrogens, oral contraceptives
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Extracted information for letrozole only.
DOSAGE AND ROUTES • Adult: PO 2.5 mg/day Infertility (unlabeled) • Adult: PO 2.5, 5, 7.5 mg/day × 5 days, usually days 3-7 of menstrual cycle Idiopathic short stature, constitutional delayed puberty (unlabeled) • Adolescent and child ≥9 (male): PO 2.5 mg/day; use with testosterone for delayed puberty
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Available forms: Tabs 2.5 mg
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Administer: • Without regard to meals; with small glass of water • May administer bisphosphonates to increase bone density
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Extracted information for letrozole only.
Assess: • Pain: Assess pain baseline and peri- odically • Hepatic studies before, during therapy (bilirubin, AST, ALT, LDH) as needed or monthly • Bone density studies, cholesterol/ lipid levels, pregnancy testing
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Evaluate: • Therapeutic response: decrease in size of tumor
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • To report allergic reactions (rash; hives; difficulty breathing; tightness in chest; swelling of mouth, face, lips, tongue) • To report vaginal bleeding, diarrhea, chest/bone pain • To use adequate contraception in peri menopausal, recently postmenopausal women, fetal risk • To avoid driving or other hazardous activities until response is known, dizzi- ness may occur
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Extracted information for letrozole only.
PHARMACOKINETICS Metabolized in liver, excreted in urine, peak 2 days, terminal half-life 48 hr, steady state 2-6 wk
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Filter the extracted dose blocks for this individual drug.
• Adult: PO 2.5 mg/day Infertility (unlabeled)
Candidate age grouping · source page 766
• Adult: PO 2.5, 5, 7.5 mg/day × 5 days, usually days 3-7 of menstrual cycle Idiopathic short stature, constitutional delayed puberty (unlabeled)
Candidate age grouping · source page 766
• Adolescent and child ≥9 (male): PO 2.5 mg/day; use with testosterone for delayed puberty
Candidate age grouping · source page 766