Anastrozole is a weak inhibitor of cytochrome P450 in vitro and not expected to have clinically significant interactions with drugs metabolised by cytochrome P450.

Estrogen use with anastrozole - use other options for conditions in which estrogen is indicated, if estrogen is used.

Hot flushes, Vaginal dryness, vaginal bleeding,

Hair thinning, Amorexia, Nausea, vomiting, Diarrhoea,

Headache, Arthlagia,

Bone fractures,

Rash (including Stevens Johnson syndrome)

Asthenia and drowsiness may intially affect ability to drive or operate machinery.

Pregnancy and lactation,

moderate or severe hepatic disease/renal impairment ,

premenstrual women.

Special Precautions

Estrogen containing therapies should not be used with anastrozole as they may diminish its pharmacologic action.

Tamoxifen should not be co-administered with anastrazole.

Indication-

Advanced breast cancer in potmenopausal women

Dosage-

For early disease 1mg daily, recommended duration of therapy is 5 years.

Refer Precautions and contraindcations

Pharmacology

Anastrazole is a reversible (Type II) nonsteroidal anomatase inhibitor. Aramatase belongs to the group of cyclochrome P-450 enzymes and catalyses the final and rate-limiting step in conversion of androgens to estrogens in peripheral tissues.

Pharmacokinetics

After oral adminostration,anastrazole is rapidly and completely absorbed from the gastrointestinal tract.

Food slightly decreases its rate of absorption.

Minimum plasma levels are reached approximately 2 hours after dosing.

Steady state concentration is reached after 9-10 days o once daily administration and it is 3-4 fold higher than after single dose administration.

The estimated half-life of Anastrazole is approximately 40- 50 hrs,

Food slightly decreases its rate of absorption.

Use contra-indicated in pregnancy and lactation.