Anacare1 mg

Anacare is a non-steroidal aromatase inhibitor indicated in postmenopausal women for hormone receptor (HR)-positive breast cancer. Its established, evidence-based uses are:

• Adjuvant treatment of HR-positive early breast cancer in postmenopausal women (FDA-approved, guideline-supported first-line adjuvant option).
• First-line treatment of HR-positive or hormone receptor-unknown locally advanced or metastatic breast cancer in postmenopausal women.
• Second-line treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy.

Patients with estrogen receptor-negative disease, and those who did not previously respond to tamoxifen, are unlikely to respond to Anacare.

Not indicated / off-label

Anacare is not indicated in premenopausal women, because its mechanism of lowering estrogen depends on postmenopausal physiology (peripheral aromatization); it does not reliably suppress ovarian estrogen production. It is sometimes used off-label (unlicensed, based on limited evidence) for conditions such as pubertal gynecomastia in boys or fertility-related ovulation induction protocols, but efficacy and safety for these uses have not been established, and such use should occur only under specialist supervision.

Anacare is an orally active, potent and highly selective non-steroidal aromatase inhibitor. It belongs to the class of hormonal antineoplastic agents used to treat hormone-sensitive breast cancer in postmenopausal women. Unlike cytotoxic chemotherapy, Anacare works by reducing the body's production of estrogen, thereby depriving estrogen-dependent tumor cells of the hormone signal they need to grow.

It is supplied as an oral tablet (typically 1 mg strength) and is taken once daily as long-term maintenance therapy under oncologist supervision.

Aromatase Inhibitor (non-steroidal) — Hormonal Antineoplastic Agent used in the treatment of hormone receptor-positive breast cancer.

Mechanism

Anastrozole potently and selectively inhibits the aromatase enzyme, which converts androgens (androstenedione and testosterone) produced in the adrenal glands and peripheral tissues into estrogens (estrone and estradiol). In postmenopausal women, peripheral aromatization is the principal source of circulating estrogen. By blocking this pathway, Anastrozole significantly lowers serum estradiol levels, depriving estrogen receptor-positive breast tumor cells of the hormonal stimulus that drives their growth.

Anastrozole does not have significant effects on adrenal corticosteroid or aldosterone synthesis, so routine corticosteroid replacement is not required.

Pharmacokinetics

• Absorption: Well absorbed orally; food does not clinically affect the extent of absorption.
• Distribution: Approximately 40% bound to plasma proteins.
• Metabolism: Extensively metabolized in the liver (N-dealkylation, hydroxylation, glucuronidation).
• Elimination: Mean terminal elimination half-life of approximately 50 hours; roughly 10% is excreted unchanged in urine, the remainder as metabolites in urine and feces.

Well-documented, clinically significant interactions with Anacare include:

• Tamoxifen: Concurrent use is not recommended. Tamoxifen has been shown to reduce plasma concentrations of Anacare by approximately 27%, and combination therapy showed no additional efficacy benefit over Anacare alone in clinical trials.
• Estrogen-containing medicines (e.g., hormone replacement therapy, estrogen-containing contraceptives): Should not be co-administered, as estrogens would counteract the estrogen-lowering effect and reduce therapeutic benefit.
• Warfarin and other anticoagulants: No clinically significant pharmacokinetic interaction has been demonstrated with warfarin, but periodic monitoring is reasonable given the oncology treatment context.

Anacare is not a significant inhibitor of major cytochrome P450 enzymes at therapeutic doses, so it is unlikely to meaningfully alter the metabolism of most other co-administered drugs; nonetheless, patients should inform their physician of all medicines, supplements, and herbal products being used.

Adverse effects reported with Anacare in clinical trials, listed by frequency:

Common (may affect more than 1 in 10 people)

• Hot flashes (vasomotor symptoms)
• Joint pain and stiffness (arthralgia) — common and sometimes treatment-limiting
• Fatigue/asthenia and general weakness
• Mood changes, including low mood and depressive symptoms
• Nausea, headache, and insomnia
• Bone thinning (osteoporosis) and increased fracture risk with long-term use
• Elevated blood cholesterol

Less common but serious

• Severe allergic reactions (facial/throat swelling, anaphylaxis)
• Severe skin reactions (blistering, ulceration, Stevens-Johnson-type reactions — rare)
• Liver enzyme abnormalities/hepatitis
• Ischemic cardiovascular events, particularly in patients with pre-existing heart disease (see Precautions)

Patients should seek prompt medical attention for severe rash, swelling, breathing difficulty, chest pain, or yellowing of the skin/eyes.

Pregnancy: Anacare is contraindicated in pregnancy and can cause fetal harm based on animal reproduction studies. It must not be used by women who are or may become pregnant. Postmenopausal status should be confirmed before starting therapy; in women of uncertain menopausal status, pregnancy must be excluded first. Effective non-hormonal contraception is advised for women who are not clearly postmenopausal, continued during treatment and for at least 3 weeks after the last dose.

Lactation: It is not known whether Anacare passes into breast milk. Because of the potential for serious adverse reactions in a nursing infant, breastfeeding is not recommended during treatment and for at least 2 weeks after the last dose. As Anacare is used almost exclusively in postmenopausal women, lactation is rarely a practical concern, but the physician should be consulted regarding any breastfeeding plans.

• Bone health: Anacare lowers estrogen, which is protective for bone density; treatment is associated with decreased bone mineral density and increased fracture risk. Baseline and periodic bone density (DEXA) monitoring is recommended, with calcium and vitamin D supplementation, and bisphosphonate or other bone-protective therapy considered if osteoporosis or significant bone loss develops.
• Cardiovascular risk: An increased incidence of ischemic cardiovascular events has been observed compared with tamoxifen, particularly in patients with pre-existing ischemic heart disease. Cardiovascular risk factors should be assessed and monitored during treatment.
• Cholesterol: Elevations in serum cholesterol have been reported; lipid monitoring may be appropriate, especially in patients with pre-existing hyperlipidemia.
• Concurrent hormonal therapy: Should not be combined with tamoxifen or estrogen-containing medicines, which reduce its effectiveness (see Interactions).
• Hepatic impairment: Use with caution in severe hepatic impairment, as this population has not been studied; periodic liver function monitoring is prudent.
• Menopausal status: Confirm postmenopausal status before initiating therapy, as efficacy and appropriateness depend on it.

Limited clinical experience with Anacare overdose exists. Doses up to 60 mg as a single dose and up to 10 mg daily have been tolerated in trials without life-threatening effects, but this does not mean higher doses are safe. There is no specific antidote for Anacare overdose.

If an overdose is suspected, seek immediate medical attention or contact emergency services / a poison control center. Management is supportive and symptomatic, including monitoring of vital signs and general clinical status; because Anacare has low plasma protein binding, dialysis may be considered by treating physicians if clinically indicated. Do not attempt home treatment for a suspected overdose.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

• Renal impairment: No dosage adjustment is required, as only about 10% of Anacare is excreted unchanged via the kidneys; caution is still advised in severe renal impairment due to limited specific data.
• Hepatic impairment: No dosage adjustment needed for mild-to-moderate impairment. Anacare has not been studied in severe hepatic impairment; use only with caution and close monitoring.
• Elderly: No dosage adjustment is necessary based on age alone.
• Pediatric patients: Safety and efficacy have not been established for routine pediatric use; see Pediatric Uses.
• Men: Anacare is not FDA-approved for use in men; any use would be off-label and should only occur under specialist supervision.

For adjuvant treatment of early breast cancer, Anacare is commonly continued for up to 5 years, based on major clinical trial data, though the optimal total duration (including possible extended therapy) should be individualized by the treating oncologist based on recurrence risk and tolerability. For advanced or metastatic disease, Anacare is continued until disease progression or unacceptable toxicity occurs. Treatment should never be stopped or interrupted without consulting the prescribing physician.

Aromatase inhibitors (non-steroidal); Hormonal antineoplastic agents used in breast cancer treatment.

D (legacy FDA pregnancy category system). Current U.S. labeling follows the Pregnancy and Lactation Labeling Rule (PLLR) narrative format and states that this medicine can cause fetal harm; it remains contraindicated in pregnancy.

Safety and efficacy of Anacare in pediatric patients have not been established for routine use. It has been studied in limited clinical trials for pubertal gynecomastia in boys and for McCune-Albright Syndrome in girls, but these trials did not demonstrate a statistically significant benefit over placebo for the studied endpoints. Anacare is therefore not recommended for use in children outside of specialist-supervised clinical settings.