Steroidal aromatase inhibitor

Exemestane

Brand names: Aromasin

Exemestane is a steroidal aromatase inhibitor used in the treatment of oestrogen-receptor-positive breast cancer in postmenopausal women.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It irreversibly inactivates the aromatase enzyme, blocking peripheral conversion of androgens to oestrogens and thereby lowering circulating oestrogen.

Prescribing in practice

Oestrogen depletion accelerates bone loss, so bone health should be assessed and managed to reduce fracture risk during treatment.
It is only effective in postmenopausal women and should not be used where ovarian function persists.
Arthralgia, hot flushes and fatigue are common and may affect adherence.

Monitoring

Monitor bone mineral density and assess fracture risk, and review tolerability of musculoskeletal and vasomotor effects.

Counselling the patient

Joint aches and hot flushes are common; discuss troublesome symptoms rather than stopping treatment.
Bone-protecting measures, including calcium, vitamin D and exercise, are important.
Take the tablet consistently and continue for the full prescribed course.

Evidence & guidelines

Aromatase inhibitors including exemestane are recommended by NICE within adjuvant endocrine therapy for postmenopausal hormone-receptor-positive breast cancer.

Reference: NICE TA112; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways