This is a nonsteroidal inhibitor of the aromatase (oestrogen synthetase) system.

Indications: advanced breast cancer in postmenopausal women (including those in whom other anti-oestrogen therapy has failed); early invasive breast cancer in postmenopausal women after standard adjuvant Tamoxifen therapy; pre-operative therapy to those with localized hormone receptor positive disease, to allow subsequent breast conserving surgery.

Cautions: severe renal impairment

Contra-indications: severe hepatic impairment; not indicated for pre-menopausal women, pregnancy & breast feeding.

Side Effects: hot flushes, nausea, vomiting, fatigue, headache, dyspepsia, constipation, diarrhoea, depression, anorexia, appetite increase, hypercholesterolemia, alopecia, increased sweating, rash, peripheral oedema, musculoskeletal pain, osteoporosis, bone fracture etc.

Dose: Po 2.5mg daily, (for 3 years after tamoxifen), discontinue if tumour progression occurs.