Arodex® (Anastrozole USP), is a non-steroidal aromatase inhibitor.It is a benzyltriazole derivative and its chemical name is α,α,α`α-tetramethyl- 5- (1H- 1, 2, 4- triazol- 1- ylmethyl) -1, 3 benzenediacetonitrile. Arodex® is a white to off-white powder. It has moderate aqueous solubility and is freely soluble in methanol, acetone, ethanol, tetrahydrofuran and very soluble in acetonitrile. The chemical formula of Arodex is C17H19N5 and the molecular weight is 293.4 and the structural formula is:
Each film coated tablet contains Anastrozole USP 1 mg.
Mechanism of action
Decreases estrogen biosynthesis by selective inhibition of aromatase (estrogen synthetase). Treatment of breast cancer has included a variety of efforts to decrease estrogen levels (ovariectomy, adrenalectomy, hypophysectomy) or to inhibit estrogen effects (antiestrogens and progestational agents). These interventions lead to decrease tumor mass or delay progression of tumor growth. In postmenopausal women, estrogens are mainly derived from the action of the aromatase enzyme, which converts adrenal androgens (primarily androstenedione and testosterone) to estrone and estradiol. The suppression of estrogen biosynthesis in peripheral tissues and in the cancer tissue can therefore be achieved by specifically inhibiting the aromatase enzyme.
Protein binding 40%
Metabolism 85% hepatic
Half-life 72 hours
Excretion Renal, 11%
Anastrozole USP 1 mg
Adjuvant treatment of post-menopausal women with hormone receptor-positive early breast cancer, and also advanced breast cancer in post-menopausal women. First-line treatment of hormone receptor-positive post-menopausal women who have received 2 to 3 years of adjuvant tamoxifen.
Dosage and administration
Adults including the elderly : 1 (one) mg tablet to be taken orally once a day.
Renal impairment : No dose change is recommended in patients with mild or moderate renal impairment.
Hepatic impairment : No dose change is recommended in patients with mild hepatic impairment. For early disease, the recommended duration of treatment should
be 5 years.
Possible side effects
Adverse reactions occurring with anastrozole are: 1) Skin reactions; 2) Allergic reactions with difficulty in respiration; and 3) Changes in blood tests of the liver function, including inflammation of the liver with symptoms that may include a general feeling of not being well, with or without jaundice, liver pain or liver swelling. Common adverse reactions (occurring with an incidence of > 10%) in women taking anastrozole include: hot flashes, asthenia, arthritis, pain, pharyngitis, hypertension, depression, nausea and vomiting, rash, osteoporosis, peripheral edema, increased cough, and lymphedema. Occasional adverse reactions: Flu syndrome, malaise, breast pain, cardiovascular and hematologic effects, insomnia, nervousness, headache, rash and respiratory effects.
Anastrozole is contraindicated in pregnant and lactating women, patients with severe renal impairment (Creatinine clearance less than 20 mL/min), patients with moderate to severe hepatic disease and known hypersensitivity to anastrozole or to any of the excipients. Oestrozen-containing therapies should not be co-administered with anastrazole as they would negate its pharmacological action.
Antipyrine and cemetidine clinical interaction studies indicate that the co-administration of anastrozole with other drugs is unlikely to result in clinically significant drug interactions mediated by cytochrome P450. Tamoxifen should not be co-administered with anastrozole as this may reduce its pharmacological action.
There are no data to support the safe use of anastrozole in patients with moderate or severe hepatic impairment, or patients with severe impairment of renal function (creatinine clearance less than 20 mL/min). Women with osteoporosis or at risk of osteoporosis should have their bone mineral density at regular intervals monitored.
There are no data available for the use of anastrozole with LHRH analogues. This product contains lactose. Patients with rare hereditary problems of galactose intolerance, the lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Product should be stored within 30°C.
Arodex® 1 mg tablet: Each box contains 3×10 tablets in blister pack.