Overview

Anastrozole 1 mg is a selective aromatase inhibitor that blocks the peripheral conversion of androgens into estradiol, the steroid hormone that fuels hormone-receptor-positive breast tumors. In postmenopausal patients this enzymatic blockade removes the dominant estrogen source and forms the biochemical foundation of long-term adjuvant endocrine treatment.

How It Works

The aromatase enzyme (CYP19A1) converts androstenedione and testosterone into estrone and estradiol in adipose tissue, skin, and breast. Anastrozole binds the enzyme in a competitive, reversible manner, so peripheral estrogen synthesis falls to near-undetectable concentrations without raising gonadotropin levels. Because ovarian function has already ceased after menopause, the drug alone achieves profound systemic estrogen depletion, starving ER-dependent clones of their growth signal. This mechanism contrasts with tamoxifen, which occupies the estrogen receptor rather than suppressing ligand production.

Indications

Anastrozole is indicated as adjuvant therapy for hormone-receptor-positive early breast cancer in postmenopausal women and for first- or second-line treatment of advanced HR-positive disease. It is also used in the extended-adjuvant setting to reduce late contralateral and ipsilateral events. Selection should follow hormone-receptor status confirmed by local pathology.

Dosage & Administration

The standard oral dose is one 1 mg film-coated tablet taken once daily, with or without food, on a continuous basis. Each box from the listed supply contains 28 tablets, providing a four-week cycle that simplifies monthly procurement planning. Dose adjustment for mild renal or hepatic impairment is generally unnecessary, but treatment continues until disease progression or a fixed adjuvant duration agreed with the prescriber.

Storage & Sourcing

Store below 30°C in the original blister pack, protected from light and moisture. Keep tablets in their carton until use and do not transfer to unlabeled containers. For B2B distribution, maintain warehouse humidity below 65 percent and rotate stock by the printed expiry date to preserve tablet integrity across multi-month supply contracts.

FAQ

Q: How does Anastrozole differ mechanistically from tamoxifen? A: Tamoxifen is a receptor antagonist that competes with estrogen at the ER binding site, whereas Anastrozole suppresses the ligand itself by inhibiting aromatase. This upstream blockade is why it is reserved for postmenopausal patients whose ovaries no longer produce estrogen.

Q: Why is Anastrozole restricted to postmenopausal women? A: Before menopause the ovaries remain the primary estrogen source, so blocking peripheral aromatase alone cannot lower circulating estrogen enough. Premenopausal use requires ovarian suppression, which is outside the standard Anastrozole indication.

Q: Does the 1 mg strength require tablet splitting for long-term therapy? A: No. The 1 mg tablet is the fixed daily dose, so no splitting is needed; the 28-tablet box delivers a complete four-week course and supports uninterrupted adherence.