buy Arimidex, sold under the brand name Arimidex among others, is a medication used in addition to other treatments for breast cancer. Specifically it is used for hormone receptor-positive breast cancer. It has also been used to prevent breast cancer in those at high risk. It is taken by mouth.
Common side effects of anastrozole include hot flashes, altered mood, joint pain, and nausea. Severe side effects include an increased risk of heart disease and osteoporosis. Use during pregnancy may harm the baby. Anastrozole is in the aromatase-inhibiting family of medications. It works by blocking the produc australiation of estrogens in the body, and hence has antiestrogenic effects.
Anastrozole was patented in 1987 and was approved for medical use in 1995. It is on the World Health Organization’s List of Essential Medicines. Anastrozole is available as a generic medication. In 2017, it was the 258th most commonly prescribed medication in the United States, with more than one million prescriptions.
buy Arimidex is used in the treatment and prevention of breast cancer in women. The Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial was of localized breast cancer and women received either anastrozole, the selective estrogen receptor modulator tamoxifen, or both for five years, followed by five years of follow-up. After more than 5 years the group that received anastrozole had better results than the tamoxifen group. The trial suggested that anastrozole is the preferred medical therapy for postmenopausal women with localized estrogen receptor–positive breast cancer.
Anastrozole is used at a dosage of 0.5 to 1 mg/day in combination with the antiandrogen bicalutamide in the treatment of peripheral precocious puberty, for instance due to familial male-limited precocious puberty (testotoxicosis) and McCune–Albright syndrome, in boys.
Contraindications of anastrozole include hypersensitivity to anastrozole or any other component of anastrozole formulations, pregnancy, and breastfeeding. Hypersensitivity reactions to anastrozole including anaphylaxis, angioedema, and urticaria have been observed.
Common side effects of anastrozole (≥10% incidence) include hot flashes, asthenia, arthritis, pain, arthralgia, hypertension, depression, nausea and vomiting, rash, osteoporosis, bone fractures, back pain, insomnia, headache, bone pain, peripheral edema, coughing, dyspnea, pharyngitis, and lymphedema. Serious but rare adverse effects (<0.1% incidence) include skin reactions such as lesions, ulcers, or blisters; allergic reactions with swelling of the face, lips, tongue, and/or throat that may cause difficulty swallowing or breathing; and abnormal liver function tests as well as hepatitis.
Anastrozole is thought to have clinically negligible inhibitory effects on the cytochrome P450 enzymes CYP1A2, CYP2A6, CYP2D6, CYP2C8, CYP2C9, and CYP2C19. As a result, it is thought that drug interactions of anastrozole with cytochrome P450 substrates are unlikely. No clinically significant drug interactions have been reported with anastrozole as of 2003.
Anastrozole does not affect circulating levels of tamoxifen or its major metabolite N-desmethyltamoxifen. However, tamoxifen has been found to decrease steady-state area-under-the-curve levels of anastrozole by 27%. But estradiol levels were not significantly different in the group that received both anastrozole and tamoxifen compared to the anastrozole alone group, so the decrease in anastrozole levels is not thought to be clinically important.
buy Arimidex works by reversibly binding to the aromatase enzyme, and through competitive inhibition blocks the conversion of androgens to estrogens in peripheral (extragonadal) tissues. The medication has been found to achieve 96.7% to 97.3% inhibition of aromatase at a dosage of 1 mg/day and 98.1% inhibition of aromatase at a dosage of 10 mg/day in humans. As such, 1 mg/day is considered to be the minimal dosage required to achieve maximal suppression of aromatase with anastrozole. This decrease in aromatase activity results in an at least 85% decrease in estradiol levels in postmenopausal women. Levels of corticosteroids and other adrenal steroids are unaffected by anastrozole.