Arimidex tablets containing active substance called as Anastrozole which is an inhibitor of Aromatase enzyme. It is active against Aromatase enzyme which is involved in estrogen synthesis. Arimidex is assort as third generation classification of Aromatase Inhibitor, includes in breast cancer treatment. In postmenopausal women, Arimidex is used to prohibit the Aromatase enzyme which is necessary to stop the estrogen production and involved in estrogen receptor positive breast cancer therapy. Arimidex is pharmacologically classified as; Aromatase inhibitor, Non-steroidal inhibitor of estrogen synthesis, Hormone receptor positive breast cancer drug
Arimidex indicated for
Arimidex used as promoting treatment:
Arimidex is mainly indicated in postmenopausal women who are suffered with hormone receptor positive early breast cancer.
First line choice:
Arimidex tablets are mediated as first line drug for the treatment involved in post-menopausal women with hormone receptor positive or hormone receptor unrecognized locally advanced breast cancer.
Second line choice:
Arimidex tablets are used as second drug choice in the post-menopausal women who are produce resistance in tamoxifen treatment. This may have indicated in patient with receptor negative disease.
Pharmacological action of Arimidex
The cancer cells growth in breast may induce and sustained by estrogen.
An Aromatase enzyme which is involved in the aromatization of adrenal androgens (androstenedione & testosterone) which get converted into estrone and estradiol, which is the conclusion of estrogen biosynthesis.
This enzyme is widely present in cells of ovary, liver, breast and also in malignant cells.
By inhibiting this enzyme, abolition of estrogen biosynthesis occurs in peripheral tissues and also in cancer tissues.
Reduction in circulating estradiol levels may leads to reduce the cancer cell growth.
Effect on estradiol:
The prescribed dose of 1mg of Arimidex which may leads to reduce the estradiol by relatively 70% within a period of 24 hours. The abolition of estradiol maintained after stopping the Arimidex therapy, for up to 6 days.
Effect on corticosteroids:
There is no variation occurs in cortisol & aldosterone secretion, no corticosteroid supplements is necessary.
Various endocrine effects:
No variation occurs in TSH; Arimidex only agitate the circulating levels of progesterone, androgens & estrogens.
Themaximum plasma concentration time occurs in a period of 2 hours. The absorption of Arimidex tablets after administration occurs very quickly .when Arimidex administered 30 minutes after food ingestion.The effect of concentration of Arimidex gets reduced by 16%, Tmax postponed from 2 to 5 hours
Only 40% of drug gets bound to the human plasma protein.
The metabolism of Arimidex arises by; Hydroxylation, Glucuronidation & N-Dealkylation These three metabolites are recovered in urine.
Nearly 85% of drug is eliminated through hepatic metabolism. Eliminated 10% in urine The terminal half-life period of Arimidex is 50 hours.
Dosage regimens and administration of Arimidex
The prescribed dose of Arimidex is one tablet 1mg should be taken orally as a single dose. In metastatic breast cancer condition, the dose should be resumed until disease advancement. In ATAC ( Arimidex , tamoxifen, alone or in combination treatment), the dose of Arimidex should be followed for 5 years.
In specific populations
The Arimidex tablets are not allowed to use for pediatric patients, no drug safety is evaluated.
Arimidex tablets should be administered with or without food. Dosage adjustment should not be suggested.
In renal & hepatic damaged patients
For mild & moderate renal impaired patients, dosage adjustment is not allowed. In severe condition, the usage of Arimidex should be in caution.
For mild or moderate hepatic impaired patients, dosage adjustment should not be suggested In severe condition, use with caution.
The maximum dose of Arimidex is 10mg should be given to post menopausal women with metastatic breast cancer. No special antidote is preferred, therapy should be symptomatic. Signs and symptoms associated to the over dosage of Arimidex should be monitored. Provide general supportive measures to the patients who are suffered with over dosage of Arimidex.
Common side effects
Pain, Arthralgia, Hypertension, Depression, Nausea, Vomiting, Rash, Osteoporosis, Fractures, Back pain, Insomnia, Headache, Bone pain, Hot flushes, Asthenia, Arthritis, Peripheral edema, Cough, Dyspnea, Pharyngitis, Lymphoedema If an adverse effect persists, discontinue the therapy.
For adjuvant therapy
Similar to that, some variations like; Vasodilatations, GI disorders, Hypercholestremia, Leucorrhea, UTI, Breast pain, Vulvovaginitis, Infection, Accidental injury, Flu like syndrome, Chest pain, Neoplasm, Cyst, Vaginal hemorrhage, Vaginitis, Ischemic cardiac disease, Venous thromboembolic events, Deep venous thromboembolic events, Ischemic Cerebrovascular event, Endometrial cancer
Ischemic cardiovascular events
During the Arimidex treatment, patients may affect with high incidence of ischemic cardiovascular events. This condition may occur in ATAC trials.
During Arimidex therapy, patient may suffer with diminishing the lumbar spine & total hip bone mineral density levels. This condition is occurring at high range in tamoxifen therapy, to reduce this adverse patient may frequently examined with bone mineral density.
In Arimidex receiving patients have high chance in elevation of cholesterol.