ARIMIDEX Tablets – Hormone Therapy for Postmenopausal Breast Cancer

ARIMIDEX is an oral medication containing anastrozole, used primarily to treat hormone receptor-positive breast cancer in postmenopausal women. It functions as an aromatase inhibitor, lowering estrogen levels that can promote cancer growth.

ARIMIDEX is indicated for the following uses in postmenopausal women:

• Adjuvant treatment of hormone receptor-positive early breast cancer.
• First-line treatment for locally advanced or metastatic breast cancer that is hormone receptor-positive or of unknown receptor status.
• Treatment of advanced breast cancer after disease progression on tamoxifen therapy. Patients with estrogen receptor-negative disease or those who did not respond to tamoxifen are unlikely to benefit.

Anastrozole

ARIMIDEX contains anastrozole, which works by blocking the aromatase enzyme that converts androgens into estrogen. Reducing estrogen levels in postmenopausal women helps slow or stop the growth of hormone receptor-positive breast cancer cells that need estrogen to grow.

The recommended dose is one 1 mg tablet taken orally once daily, with or without food. For advanced breast cancer, treatment should continue until tumor progression occurs.

The optimal duration for adjuvant treatment of early breast cancer is not definitively known, but in clinical trials, ARIMIDEX was administered for five years.

No dosage adjustments are necessary for elderly patients or those with renal impairment. For mild-to-moderate hepatic impairment, no dose changes are recommended; ARIMIDEX has not been studied in severe hepatic impairment.

ARIMIDEX is contraindicated in patients with known hypersensitivity to anastrozole or any of its excipients. Reported hypersensitivity reactions include anaphylaxis, angioedema, and urticaria.

• Ischemic cardiovascular events: Patients with pre-existing ischemic heart disease experienced a higher rate of ischemic events on ARIMIDEX compared to tamoxifen. Careful consideration of risks and benefits is advised.
• Bone health: ARIMIDEX use may decrease bone mineral density; monitoring is recommended as it may increase fracture risk.
• Cholesterol: Serum cholesterol elevations have been observed; lipid monitoring is advised.
• Embryo-fetal toxicity: ARIMIDEX can cause fetal harm. Females of reproductive potential should use effective contraception during treatment and for at least three weeks after the last dose.

Common side effects occurring in 10% or more of patients include hot flashes, fatigue (asthenia), joint pain (arthritis and arthralgia), pain, hypertension, depression, nausea, vomiting, rash, osteoporosis, fractures, back pain, insomnia, headache, peripheral edema, cough, dyspnea, pharyngitis, and lymphedema.

Serious but rare adverse reactions (<0.01%) include severe skin reactions (ulcers, blisters), allergic reactions such as angioedema and anaphylaxis, and liver function changes including hepatitis symptoms.

Patients on ARIMIDEX experienced a higher incidence of fractures and joint disorders compared to tamoxifen. They had fewer occurrences of vaginal bleeding, endometrial cancer, hot flashes, venous thromboembolism, and ischemic cerebrovascular events compared to tamoxifen.

No specific drug interactions requiring dose adjustment are stated in the labeling.

Pregnancy: ARIMIDEX can cause fetal harm based on animal studies and its mechanism of action. Women should be advised of this risk and use effective contraception during treatment and for 3 weeks after the last dose.

Lactation: Information on breastfeeding is not provided in the supplied label.

Specific overdose symptoms and management are not described in the supplied evidence.

Store tablets as directed on the packaging. Specific temperature or handling instructions are not detailed in the supplied evidence.