Femara Medication Guide

Active Ingredient

Femara contains the active ingredient letrozole, which belongs to a class of medications known as aromatase inhibitors. It is used primarily in the treatment of hormone-responsive breast cancer.

Indications for Use

Femara is indicated for the treatment of postmenopausal women with hormone receptor-positive early breast cancer, as an adjuvant treatment. It is also used to treat advanced breast cancer in postmenopausal women with disease progression following anti-estrogen therapy.

Mechanism of Action

Letrozole works by inhibiting the enzyme aromatase, which converts androgens into estrogens in the body. By reducing estrogen levels, letrozole helps to decrease the growth of estrogen-dependent breast cancer cells.

Dosage Information

The recommended dose of Femara is 2.5 mg once daily, taken without regard to meals. Treatment should continue until tumor progression is evident.

Administration Guidelines

Femara should be taken at the same time each day to maintain an even level of the drug in the body. Swallow the tablet whole, with a sufficient amount of water. Do not crush or chew the tablet.

Storage Conditions

Store Femara at room temperature, between 20°C to 25°C (68°F to 77°F), in a tightly closed container. Protect from light and moisture.

Pharmacokinetics

Letrozole is absorbed quickly after oral administration, reaching peak plasma concentrations within 1 hour. The drug’s half-life is approximately 48 hours, which supports once-daily dosing.

Metabolism and Excretion

Femara is primarily metabolized in the liver by CYP3A4 and CYP2A6 enzymes. Less than 10% of the drug is excreted unchanged in the urine.

Contraindications

Femara should not be used in premenopausal women. It is contraindicated in individuals with a known hypersensitivity to letrozole or any of its excipients.

Drug Interactions

Concomitant use of drugs known to affect CYP450 enzymes may alter the metabolism of letrozole. Monitor for interactions with medications such as phenytoin, carbamazepine, and rifampin.

Adverse Reactions

Common adverse reactions include hot flashes, arthralgia, and osteoporosis. Less common side effects may include elevated liver enzymes, hypercholesterolemia, and carpal tunnel syndrome.

Monitoring Requirements

Regular monitoring of bone mineral density (BMD) is recommended for patients taking Femara long-term, due to the risk of osteoporosis. Additionally, liver function tests should be performed periodically.

Special Populations

Renal impairment: No dosage adjustment is needed for patients with mild to moderate renal impairment. Use with caution in severe renal impairment.

Hepatic Impairment

No initial dose adjustment is required for patients with mild to moderate hepatic impairment. Patients with severe hepatic dysfunction should be monitored closely.

Use in Elderly

Femara has been shown to be safe and effective in both elderly and younger postmenopausal women. No dose adjustment is necessary for elderly patients.

Pregnancy Category

Femara is classified as Pregnancy Category D. It is contraindicated in women who are or may become pregnant due to potential fetal harm.

Breastfeeding Considerations

Breastfeeding is not recommended while taking Femara, as it is not known whether the drug is excreted in human milk. The potential risks to the infant should be considered.

Patient Counseling Information

Patients should be informed about the importance of adherence to prescribed dosing schedules. Encourage reporting of any unusual symptoms or side effects to their healthcare provider.

Clinical Studies

Clinical trials have demonstrated the efficacy of Femara in increasing overall survival and disease-free survival in postmenopausal women with hormone-responsive breast cancer.

Cost and Availability

Femara is available by prescription and is often covered by insurance plans. Generic versions may also be available under the name letrozole.

Brand vs. Generic

The efficacy, safety, and pharmacokinetic profiles of generic letrozole are equivalent to the brand-name version, Femara. The choice between them may depend on cost and patient preference.