Natco exemestane tablets xtane

[Drug Name]

Generic Name: Exemestane Tablets

[Composition] The main active ingredient of this product is exemestane.

[Description] This product consists of white or off-white tablets, or film-coated tablets; when the coating is removed, the core appears white or off-white.

[Indications] Indicated for postmenopausal patients with advanced breast cancer whose disease has progressed following treatment with tamoxifen.

[Specification] 25 mg

[Dosage and Administration] One tablet (25 mg) once daily, taken orally after a meal. No dosage adjustment is required for patients with mild to moderate renal impairment.

[Adverse Reactions] The main adverse reactions associated with this product include: nausea, dry mouth, constipation, diarrhea, dizziness, insomnia, rash, fatigue, fever, edema, pain, vomiting, abdominal pain, increased appetite, weight gain, etc. Additionally, literature reports have noted hypertension, depression, anxiety, dyspnea, and cough. Other reported effects include a decrease in lymphocyte count and abnormal liver function parameters (such as alanine aminotransferase). In clinical trials, only 3% of patients discontinued treatment due to adverse reactions; these discontinuations occurred primarily within the first 10 weeks of exemestane therapy. Discontinuation due to adverse reactions in the later stages of treatment was uncommon (0.3%).

[Contraindications]

1. Contraindicated in patients with known hypersensitivity to this product or to any of its excipients.

2. Contraindicated in pregnant women, nursing mothers, and children.

[Precautions] Exemestane tablets are generally not used in premenopausal women. Exemestane should not be administered concomitantly with estrogen-containing medications, as this may result in interference effects. Use with caution in patients with moderate to severe hepatic or renal impairment. Exemestane overdose may lead to an increased incidence of non-fatal adverse reactions. Athletes should use this product with caution.

[Use in Pregnant and Nursing Women] Contraindicated.

[Use in Children] Contraindicated.

[Use in the Elderly] No special precautions are required. 【Drug Interactions】 This product should not be used concomitantly with estrogen-containing medications, as this may antagonize the therapeutic effects of this product. Exemestane is primarily metabolized via cytochrome P-450 3A4 (CYP3A4); however, when administered concurrently with a potent CYP3A4 inhibitor (such as ketoconazole), the pharmacokinetics of this product remained unchanged. Therefore, it appears that CYP isoenzyme inhibitors do not exert a significant influence on the pharmacokinetics of this product. Nevertheless, the possibility that known CYP3A4 inducers may lower plasma levels of exemestane cannot be ruled out.

【Overdosage】 Clinical studies involving single doses of up to 800 mg were conducted in healthy female volunteers; additionally, clinical trials involving daily doses of up to 600 mg administered over a period of 12 weeks were conducted in postmenopausal women with advanced breast cancer. Subjects demonstrated good tolerability at these dosage levels.

In the event of an overdose, there is no specific antidote; general supportive care should be administered, including frequent monitoring of vital signs and close observation of the patient.

【Pharmacology and Toxicology】

Pharmacological Action: The growth of breast cancer cells may be dependent on the presence of estrogen. In postmenopausal women, circulating estrogens (estrone and estradiol) are primarily derived from the conversion of androgens (androstenedione and testosterone)—produced in the adrenal glands and ovaries—by aromatase enzymes located in peripheral tissues. Inhibiting estrogen production through the suppression of aromatase activity constitutes an effective and selective therapeutic strategy for treating hormone-dependent breast cancer in postmenopausal women. Exemestane is an irreversible steroidal aromatase inactivator. Structurally similar to the enzyme's natural substrate, androstenedione, it acts as a "suicide substrate" for aromatase; it inactivates the enzyme by binding irreversibly to its active site (a mechanism also referred to as "suicide inhibition"). This action results in a significant reduction in circulating estrogen levels in postmenopausal women, while exerting no significant effect on the biosynthesis of corticosteroids within the adrenal glands. Furthermore, at concentrations exceeding 600 times the level required to inhibit aromatase, the drug exerts no significant influence on other enzymes involved in the steroidogenic pathway. Toxicology Studies (See Package Insert for Details)

[Pharmacokinetics] According to published literature, following oral administration of radiolabeled exemestane to healthy postmenopausal women, absorption is rapid; at least 42% of the exemestane is absorbed from the gastrointestinal tract. Following the ingestion of a high-fat meal, plasma levels increase by approximately 40%. Exemestane is widely distributed throughout various tissues, and its plasma protein binding rate is 90%. Exemestane undergoes extensive metabolism, primarily via oxidation of the 6-methylene group and reduction of the 17-keto group. Its metabolites are either inactive or possess only weak aromatase-inhibiting activity. These metabolites are excreted primarily through urine and feces, accounting for approximately 40% of the dose in each route; less than 1% of the administered dose is excreted in the urine as unchanged drug. The mean terminal half-life of exemestane is 24 hours. In postmenopausal women with advanced breast cancer, absorption is more rapid than in healthy postmenopausal women, with time-to-peak concentrations occurring at 1.2 hours and 2.9 hours, respectively. Following repeated dosing, the mean oral clearance in patients with advanced breast cancer is 45% lower than in healthy postmenopausal women, resulting in higher circulating levels; the mean AUC in these patients is approximately twice that observed in healthy women.

In patients with moderate to severe hepatic or renal impairment, the AUC following a single oral dose of exemestane is approximately three times higher than that observed in healthy volunteers.

[Storage] Protect from light; store in a tightly closed container.

Product Specifications

Product Name: Natco Exemestane Tablets 25 mg × 30 Tablets

Generic Name: Exemestane Tablets

Composition: The active ingredient of this product is exemestane.

Dosage Form: Tablets

Specification: 25 mg × 30 Tablets

Manufacturer: Natco Pharma Ltd

Indications: Indicated for postmenopausal women with advanced breast cancer whose disease has progressed following treatment with tamoxifen.

Dosage and Administration:One tablet (25 mg) once daily, taken orally after a meal. No dosage adjustment is required for patients with mild hepatic or renal impairment.