Arimidex (Anastrozole) belongs to the group of cancer-fighting medications known as antineoplastics, and specifically to the group of antineoplastics known as nonsteroidal aromatase inhibitors. It fights Breast Cancer by inactivating an enzyme known as aromatase. This prevents the enzyme from supplying the estrogen that allows certain types of breast cancers to grow.
Arimidex (Anastrozole) can be used after surgery to treat postmenopausal women with hormone-receptor-positive early breast cancer. Arimidex (Anastrozole) can also be used to treat postmenopausal women with advanced breast cancer.

Anastrozole can also be used off-label in men. Some reasons for taking anastrozole in men are low testosterone levels, prostate conditions, enlarged breasts, or high estrogen levels caused by steroid use. The standard dosage of Anastrozole for men is typically 1 mg per day. This dosage is often recommended by healthcare professionals to regulate estrogen levels and manage related symptoms. However, it is essential to note that dosages may vary based on individual factors, such as the severity of estrogen-related issues and response to treatment. Anastrozole can improve testosterone effects and reduce estrogen-related side effects in men.

Your doctor may have suggested Arimidex (Anastrozole) for conditions other than those listed in these drug information description. If you have not discussed this with your doctor or are not sure why you are taking Arimidex (Anastrozole), speak to your doctor. Do not stop taking Arimidex (Anastrozole) without consulting your doctor.

Do not give Arimidex (Anastrozole) to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

Anastrozole is a potent and selective nonsteroidal aromatase inhibitor. By inhibiting aromatase, the conversion of androstenedione to estrone, and testosterone to estradiol, is prevented, thereby decreasing tumor mass or delaying progression in patients with tumors responsive to hormones. Anastrozole causes an 85% decrease in estrone sulfate levels.

Precautions and contraindications of Arimidex (Anastrozole) include:

• Decreased blood flow to the heart, especially if you have a history of coronary artery disease.
• Not to be used during pregnancy, as it could harm the unborn baby.
• Dizziness may occur while using this medication.
• Increased risk of ischemic cardiovascular events in women with pre-existing heart disease.
• Decreased bone density in the lower spine and hips.
• Rise in cholesterol levels.

Medications known to interact with anastrozole
Note: Showing generic names only.

Include all brand names and combination drug names.

chlorotrianisene
conjugated estrogens
conjugated estrogens topical
dehydroepiandrosterone
dienestrol topical
diethylstilbestrol
esterified estrogens
estradiol
estradiol topical
estramustine
estrone
estropipate
estropipate topical
ethinyl estradiol
fezolinetant
fostamatinib
quinestrol
tamoxifen
thalidomide
tucatinib

Anastrozole alcohol/food interactions
There is 1 alcohol/food interaction with anastrozole.

Anastrozole disease interactions
There are 4 disease interactions with anastrozole which include:

cardiovascular
cholesterol
hepatic dysfunction
osteoporosis

The most common side effects that occur with anastrozole include:

hot flashes
weakness
bone, joint, and muscle pain or stiffness
sore throat or cough
high blood pressure
depression
nausea or vomiting
back pain
skin rash
anxiety
trouble sleeping
nervousness
headache
swelling of your legs, ankles, or feet
shortness of breath
bone fractures
swelling in your lymph nodes
If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects
Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

Osteoporosis (bone thinning or weakness). Symptoms may include: pain in your back, neck, or hips
Higher cholesterol levels. This can lead to serious heart problems.
Skin reactions. Symptoms may include:
abnormal growth on your skin (lesion)
open sores (ulcers)
blisters
tickling, tingling, pain, coldness, or numbness in parts of your hand
Liver problems. Symptoms may include:
yellowing of your skin or the whites of your eyes
pain on the right upper side of your stomach area
a general feeling of not being well

Pregnancy

ARIMIDEX may cause fetal harm when administered to a pregnant woman and offers no clinical benefit to premenopausal women with breast cancer. ARIMIDEX is contraindicated in women who are or may become pregnant. In animal studies, anastrozole caused pregnancy failure, increased pregnancy loss, and signs of delayed fetal development. There are no studies of ARIMIDEX use in pregnant women. If ARIMIDEX is used during pregnancy, or if the patient becomes pregnant while receiving this drug, the patient should be apprised of the potential hazard to the fetus and potential risk for pregnancy loss.

In animal reproduction studies, pregnant rats and rabbits received anastrozole during organogenesis at doses equal to or greater than 1 (rats) and 1/3 (rabbits) the recommended human dose on a mg/m² basis. In both species, anastrozole crossed the placenta, and there was increased pregnancy loss (increased pre-and/or post-implantation loss, increased resorption, and decreased numbers of live fetuses). In rats, these effects were dose related, and placental weights were significantly increased. Fetotoxicity, including delayed fetal development (i.e., incomplete ossification and depressed fetal body weights), occurred in rats at anastrozole doses that produced peak plasma levels 19 times higher than serum levels in humans at the therapeutic dose (AUC 0-24hr 9 times higher). In rabbits, anastrozole caused pregnancy failure at doses equal to or greater than 16 times the recommended human dose on a mg/m² basis [see Animal Toxicology and/or Pharmacology].

Nursing Mothers

It is not known if anastrozole is excreted in human milk. Because many drugs are excreted in human milk and because of the tumorigenicity shown for anastrozole in animal studies, or the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use

Clinical studies in pediatric patients included a placebo-controlled trial in pubertal boys of adolescent age with gynecomastia and a single-arm trial in girls with McCune-Albright Syndrome and progressive precocious puberty. The efficacy of ARIMIDEX in the treatment of pubertal gynecomastia in adolescent boys and in the treatment of precocious puberty in girls with McCune-Albright Syndrome has not been demonstrated.

• Store at room temperature, 15 to 30°C.
• Keep your ARIMIDEX tablets in the original container.
• Do not use ARIMIDEX after the expiry date on the blister package.
• Keep out of reach and sight of children.