Anastrozole

CAS: 120511-73-1

Chemical Name:α α α' α'-tetramethyl-5-(1H-1,2,4-triazol-1ylmethyl) 1,3-Benzenediacetionitrile

Why is Anastrozole prescribed?
Anastrozole is used to treat advanced breast cancer in postmenopausal women who have failed to respond to therapy with other drugs, such as tamoxifen (Nolvadex). Anastrozole works by decreasing the amount of estrogen your body makes, so that breast cancers which require estrogen for growth may decrease in growth rate and size.

Anastrozole is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should Anastrozole be used?
Anastrozole comes as a tablet to take by mouth. It usually is taken once a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take anastrozole exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Continue to take anastrozole even if you feel well. Do not stop taking anastrozole without talking to your doctor.

What special precautions should I follow?
Before taking anastrozole,

Tell your doctor and pharmacist if you are allergic to anastrozole, povidone, lactose, or any other drugs.
Tell your doctor and pharmacist what prescription and nonprescription medications you are taking, including vitamins.
Tell your doctor if you have or have ever had liver disease, high levels of blood cholesterol, blood clots (thrombophlebitis), or hypertension (high blood pressure).
If you are premenopausal, tell your doctor if you are pregnant. Anastrozole should not be taken during pregnancy. Therefore, premenopausal women should use a reliable method of birth control. If you become pregnant while taking anatrozole, call your doctor.
If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking anastrozole.

What special dietary instructions should I follow?
Anastrozole may cause an upset stomach. Take anastrozole with food or milk.

What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can Anastrozole cause?
Although side effects from anastrozole are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

weakness or tiredness
upset stomach or vomiting
headache
hot flashes
bone, pelvic, and back pain
cough
diarrhea
constipation
stomach pain
loss of appetite
sore throat
dizziness
rash
dry mouth
swelling of the arms, legs, or ankles (edema)
depression
numbness
vaginal hemorrhage
weight gain
sweating
increased appetite
increased blood cholesterol

If you experience any of the following symptoms, call your doctor immediately:

chest pain
shortness of breath
calf pain
redness, warmth, and swelling of arms or legs

What storage conditions are needed for Anastrozole?
Keep this medication in the container it came in, tightly closed, and out of reach of children.

Store it at room temperature and away from heat and moisture (not in the bathroom). Throw way any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

Reference:

1. Health Canada Therapeutic Products Programme. Notices of compliance (NOC)-Drugs. Available from http://www.hc-sc.gc.ca/hpb-dgps/therapeutic/htmleng/noc-drugs.html. Accessed 30 August, 2000.

2. Health Canada Therapeutic Products Programme. Patent register. Available from http://www.hc-sc.gc.ca/hpb-dgps/therapeut/htmleng/patents.html. Accessed 30 August, 2000.

3. Njar VC, Brodie AM. Comprehensive pharmacology and clinical efficacy of aromatase inhibitors. Drugs 1999;58(2):233-55.

4. Santen RJ, Harvey HA. Use of aromatase inhibitors in breast carcinoma. Endocr Relat Cancer 1999;6(1):75-92.

5. Geisler J, King N, Dowsett M, et al. Influence of anastrozole (Arimidex), a selective, non-steroidal aromatase inhibitor, on in vivo aromatisation and plasma oestrogen levels in postmenopausal women with breast cancer. Br J Cancer 1996;74(8):1286-91.

6. Yates RA, Dowsett M, Fisher GV, et al. Arimidex (ZD1033): selective, potent inhibitor of aromatase in postmenopausal female volunteers. Br J Cancer 1996;73:543-8.

7. Kvinnsland S, Anker G, Dirix LY, et al. High activity and tolerability demonstrated for exemestane in postmenopausal women with metastatic breast cancer who had previously failed on tamoxifen treatment. Eur J Cancer 2000;36(8):976-82.

8. Astrazeneca. Arimidex product monograph. Mississauga, Ontario; 7 June 2000.

9. Plourde PV, Dyroff M, Dukes M. Arimidex: a potent and selective fourth-generation aromatase inhibitor. Breast Cancer Res Treat 1994;30:103-11.

10. Higa GM, alKhouri N. Anastrozole: a selective aromatase inhibitor for the treatment of breast cancer. Am J Health Syst Pharm 1998;55(5):445-52.

11. Dowsett M, Donaldson K, Tsuboi M, et al. Effects of the aromatase inhibitor anastrozole on serum oestrogens in Japanese and Caucasian women. Cancer Chemother Pharmacol 2000;46(1):35-9.

12. Jonat W, Howell A, Blomqvist C, et al. A randomised trial comparing two doses of the new selective aromatase inhibitor anastrozole (Arimidex) with megestrol acetate in postmenopausal patients with advanced breast cancer [see comments]. Eur J Cancer 1996;32A(3):404-12.

13. Buzdar AU, Jones SE, Vogel CL, et al. A phase III trial comparing anastrozole (1 and 10 milligrams), a potent and selective aromatase inhibitor, with megestrol acetate in postmenopausal women with advanced breast carcinoma. Arimidex Study Group. Cancer 1997;79(4):730-9.

14. Buzdar A, Jonat W, Howell A, et al. Anastrozole, a potent and selective aromatase inhibitor, versus megestrol acetate in postmenopausal women with advanced breast cancer: results of overview analysis of two phase III trials. Arimidex Study Group. J Clin Oncol 1996;14(7):2000-11.

15. Buzdar A, Nabholtz JM, Robertson JF, et al. Anastrozole (Arimidex) versus tamoxifen as first-line therapy for advanced breast cancer in postmenopausal women? Combined analysis from two identically designed multicenter trials. Proc Am Soc Clin Oncol 2000;19:154a (abstract 609d).

16. Baum M, Houghton J. Arimidex, tamoxifen alone or in combination adjuvant trial in postmenopausal breast cancer. Eur J Cancer 1998;34(Suppl 1):99.

17. Anastrozole. USP DI. Volume 1. Drug information for the health care professional. 2Oth ed. Englewood, Colorado: Micromedex, Inc.; 2000.

18. Dowsett M, Tobias JS, Howell A, et al. The effect of anastrozole on the pharmacokinetics of tamoxifen in post-menopausal women with early breast cancer. Br J Cancer 1999;79(2):311-5.

19. Grimm SW, Dyroff MC. Inhibition of human drug metabolizing cytochromes P450 by anastrozole, a potent and selective inhibitor of aromatase. Drug Metab Dispos 1997;25(5):598-602.

20. Grimm SW, Dyroff MC. Inhibition of human drug metabolizing cytochromes P450 by anastrozole, a potent and selective inhibitor of aromatase. Drug Metab Dispos 1997;25(5):598-602.

21. BC Cancer Agency Breast Tumour Group. Cancer Management Guidelines: Breast Follow-up - Hormone replacement therapy after a diagnosis of breast cancer. Vancouver, British Columbia: BC Cancer Agency; 2000.

22. Brian Norris, MD. Personal Communication. BC Cancer Agency Breast Tumour Group 2001;15 March 2001.