Arimidex in breast cancer therapy!


Adjuvant therapy for early breast cancer hormone-positive in postmenopause. Treatment of common breast cancer in women in postmenopause. Adjuvant therapy of early hormone-positive breast cancer in women in postmenopause after tamoxifen therapy for 2-3 years. It is an antagonist of aromatisation hormone. During postmenopause estradiol is produced by converting androstendia into estron in peripheral tissues under the influence of the aromatist enzyme. Next, astronauts turn into estradiol. The active substance of the preparation blocks this process. This reduces the level of estradiol, which is necessary for the treatment of breast cancer. In women in postmenopause the drug in a dose of 1 mg/day causes a decrease in estradiol level by 80%. It has no progestagenic or androgenic activity; the dose of up to 10 mg/day does not affect the secretion of aldosterone and cortisol.

More Info

Effect of the drug

Highly selective, non-steroidal aromatase inhibitor. Aromatase is an enzyme which helps women in postmenopause to transform androstendia in peripheral tissues into estraine and then into estradiol. Decrease in the level of circulating estradiol has a therapeutic effect in patients with breast cancer. In postmenopause the drug in a daily dose of 1 mg causes a decrease in the level of estradiol by 80%. Arimidex does not possess progestagenic, androgenic and estrogenic activity. Arimidex in a daily dose of up to 10 mg has no effect on the secretion of cortisol and aldosterone (therefore, the drug does not require substitution administration of corticosteroids).

Special instructions:

In women with estrogen receptor-negative tumors, the efficacy of Arimidex has not been demonstrated unless there was a previous positive clinical response to tamoxifene. In case of doubts about the hormonal status of the patient, menopause should be confirmed by the determination of sexual hormones in the serum. There is no evidence of safe use of Arimidex in patients with severe liver dysfunction or severe renal failure (less than 20 ml/min). If uterine bleeding persists during Arimidex administration, gynecological consultation and observation is required. Preparations containing estrogen should not be administered simultaneously with Arimidex. By reducing the level of circulating estradiol, Arimidex may cause a decrease in the mineral density of bone tissue. In patients with osteoporosis or at risk of osteoporosis, the mineral density of bone tissue should be evaluated by densitometry (e.g. DEXA scanning) at the beginning of treatment and in dynamics. If necessary, treatment or prophylaxis of osteoporosis should be initiated under the close supervision of a physician. There is no evidence of simultaneous use of anastrozole and GnRH analogues. It is not known whether anastrozole improves treatment results when used in combination with chemotherapy. Safety data for long-term anastrozole treatment have not yet been obtained. At application of Arimidex more often, than at therapy with tamoxifene, ischemic diseases were observed, however statistically significant it was not noted. The efficacy and safety of Arimidex and tamoxifene in their concomitant use, regardless of the status of the hormone receptors, are comparable to those of single tamoxifene. The exact mechanism of this phenomenon is not yet known. Pediatric use Safety and efficacy of the drug use in children are not established. Impact on driving ability and machine control Some side effects of Arimidex, such as asthenia and drowsiness, can have a negative effect on the ability to perform work requiring increased concentration and rapid psychomotor responses. It is therefore recommended that caution is exercised when driving a car or moving machinery when these symptoms occur.

Dosage of Arimidex:

Adults, including elderly patients, are prescribed 1 mg of the drug inside once a day, for a long time. If there are signs of disease progression, the drug should be stopped. As adjuvant therapy, the recommended duration of treatment is 5 years. Patients with mild to moderate renal impairment do not require dose correction. Patients with mild liver dysfunction do not require dose correction. The tablet should be swallowed as a whole and washed down with water. It is recommended to take the drug at the same time of day.

Mechanism of action and pharmacodynamic effects:

Arimidex is a powerful and highly selective non-steroidal aromatase inhibitor. In women in the postmenopausal period estradiol is mainly produced by conversion of androstendia into estron in peripheral tissues with the help of aromatase enzyme complex. Estron is further transformed into estradiol. Decrease in the level of estradiol has a therapeutic effect in women with breast cancer. In women in the postmenopausal period, taking Arimidex in a daily dose of 1 mg led to a decrease in the level of estradiol by 80%, which was confirmed by a highly sensitive analytical test. Arimidex has no progestagenic, androgenic or estrogenic activity. Arimidex in daily doses of up to 10 mg does not affect the secretion of cortisol and aldosterone, which was measured before and after the standard ACTH stimulation test (ACTH). Therefore, there is no need for substitution therapy with corticosteroids. Two double-blind controlled clinical trials with similar design (study 1033IL / 0030 and study 1033IL / 0027) were conducted to evaluate the efficacy of Arimidex compared to tamoxifene as a first-line drug for the treatment of locally advanced or metastatic breast cancer with positive or unknown hormone receptor values in women in the postmenopausal period. In total, 1021 patients were randomized for 1 mg dose of Arimidex once a day or 20 mg dose of tamoxifene once a day. The main final results in both studies were the time to tumor progression, tumor response rate and safety. Arimidex was studied in two controlled clinical trials (trial 0004 and trial 0005) with women in the post-menopausal period with advanced breast cancer who had progressed after early treatment with tamoxifen for advanced breast or breast cancer. A total of 764 patients were randomized for use with Arimidex at a dose of 1 mg or 10 mg once a day or with Megestrol acetate at a dose of 40 mg four times a day. Time to progress and frequency of objective response were the main performance indicators. The frequency of prolonged (more than 24 weeks) stable disease, the frequency of progression and the overall survival rate were also determined. Both studies showed no significant differences between the treatment groups for any of the efficacy parameters. Additive treatment of invasive breast cancer with positive hormone receptor values in the early stages In the course of a major phase IIRI study, 93666 women were involved in the postmenopausal period with operable breast cancer treated for 5 years (see below), Arimidex was statistically predominant in tamoxifene for the survival rate without disease. Significantly greater advantages over the non-sick survival rate were observed in favor of Arimidex compared to tamoxifene in a prospective definite population with positive hormone receptor values. The combination of Arimidex and tamoxifene did not demonstrate greater efficacy than tamoxifene in all patients and in a population with positive hormone receptor values. This treatment group was derived from the study.