Aromasin (Exemestane)

Aromasin (Exemestane): Patient Guide for Australia

Basic Product Information

• International Non-Proprietary Name (INN): Exemestane
• Brand Names in Australia: Aromasin (Pfizer), generic Exemestane
• ATC Code: L02BG06
• Available Forms and Strengths: Oral tablets, 25 mg strength
• Manufacturers: Pfizer Australia Pty Ltd, various generic manufacturers
• Prescription Status: Prescription only (Schedule 4, Prescription Medicine)

Mechanism of Action

For Patients: Exemestane is a type of medicine known as an aromatase inhibitor. This means it lowers levels of oestrogen (a female hormone) in the body. Many breast cancers need oestrogen to grow, so by reducing oestrogen, Aromasin helps to slow or stop the growth of these cancers.

For Specialists: Aromasin (exemestane) is a steroidal irreversible inhibitor of the aromatase enzyme. By inactivating aromatase, exemestane prevents the peripheral conversion of androgens to oestrogens, leading to a significant reduction in circulating oestrogen concentrations in postmenopausal women.

Pharmacokinetics

• Absorption: Well absorbed after oral administration. Peak plasma levels typically reached in 1–2 hours.
• Metabolism: Extensively metabolised in the liver via CYP3A4 and aldoketoreductase enzymes. Metabolites are less active than the parent drug.
• Elimination: Excreted mainly via urine (around 40%) and bile/faeces (around 40%).
• Duration of Action: Terminal half-life is approximately 24 hours. Steady-state achieved in 7 days of daily dosing.

Use in Everyday Life and Best Practices

Aromasin is commonly prescribed for women after menopause who have hormone receptor-positive early or advanced breast cancer. It may be used after other treatments (such as tamoxifen) or as initial therapy in advanced cases. Tablets are taken by mouth, once daily. Consistency is important, so try to take your dose at the same time every day.

• Typical Adult Dose: One 25 mg tablet taken once daily.
• Duration: As directed, typically for several years for early breast cancer prevention/recurrence.
• Forgetting a Dose: Take as soon as you remember unless it is close to your next dose. Do not double up doses.
• Do not crush or split tablets unless your pharmacist advises.

Dosing in the Morning vs Evening

• Morning: Some patients find it easier to remember to take medication in the morning as part of a daily routine (e.g., after breakfast).
• Evening: No substantial clinical difference, but some patients may experience sleep disturbance or mild insomnia with evening dosing (rare).
• Key Advice: Choose a time that fits your daily routine and helps you remember to take the dose regularly. Consistency is more important than the specific timing.

Taking with Food or on an Empty Stomach

• Aromasin is better absorbed when taken after a meal. Taking with food increases the amount of medicine absorbed by the body, improving its effectiveness.
• Typical Australian breakfasts (such as cereal, toast, or fruit) are sufficient; a large meal is not required.
• If you forget to take it with food, do not be concerned, but try to take your next dose with a meal.

Interaction Warnings

Indications

Dosing According to Clinical Indications

Safety Profile and Side Effects

Like all medicines, Aromasin may cause side effects. Many people experience mild or manageable symptoms. For detailed guidance, speak with your doctor or pharmacist.

• If you experience severe side effects, contact your doctor or emergency services immediately.
• See your doctor regularly for monitoring (e.g., bone health, cholesterol levels).

Guidelines for Proper Use: Pharmacist & Clinic Advice

1. Always take Aromasin as prescribed by your doctor. Do not adjust your dose without approval.
2. Try to take your tablet at the same time every day with food (ideally breakfast or lunch).
3. Store tablets below 25°C, away from heat and moisture, and out of reach of children.
4. Do not share your medication with others, even if they have similar symptoms.
5. Keep up with follow-up appointments (e.g., for monitoring bones, cholesterol, or other health checks).
6. If you are travelling, take enough medicine for the entire trip and carry a copy of your prescription.

Alternative Treatment Options

• Non-steroidal aromatase inhibitors: Anastrozole (Arimidex, reimbursed by PBS); Letrozole (Femara, generic, reimbursed by PBS)
• SERMs: Tamoxifen (widely used as initial or sequential therapy, reimbursed by PBS)
• Other hormonal agents: Fulvestrant (Faslodex, for advanced/metastatic). May be considered if resistance to aromatase inhibitors develops.

Comparative Advantages/Disadvantages:

• Aromasin is an irreversible, steroidal inhibitor—may be used after other non-steroidal aromatase inhibitors stop working.
• Anastrozole & Letrozole are often used as first-line options due to long track records and similar efficacy for early-stage disease.
• Tamoxifen can be used before aromatase inhibitors or if side effects become troublesome.
• Aromasin, as with all aromatase inhibitors, increases risk of osteoporosis—discuss bone health management with your GP or cancer specialist.

Legal, Registration, and Reimbursement Status in Australia

• Registered with the Therapeutic Goods Administration (TGA Australia).
• Available only with a valid Australian prescription (Schedule 4).
• Listed on the Pharmaceutical Benefits Scheme (PBS) for eligible indications—reducing out-of-pocket costs for many patients.
• Not usually available for private purchase without a script.
• Most private and public hospital pharmacies stock Aromasin and generic exemestane.

Latest Research & Clinical Guidance (2022–2025)

• Recent studies and meta-analyses continue to confirm the benefit of adjuvant aromatase inhibitor therapy (including aromasin) in reducing risk of breast cancer recurrence in postmenopausal women [Smith M et al., Lancet Oncol, 2024].
• Extended use beyond 5 years may be considered for selected patients, balancing benefits for recurrence reduction against increased risk of osteoporosis and fractures (refer to Cancer Australia guidelines, 2023 update).
• Sequencing therapy: Evidence supports use of exemestane after prior tamoxifen or non-steroidal aromatase inhibitor resistance. Combination with ovarian suppression for premenopausal women remains specialist use only.
• Patient quality of life and side-effect management are under ongoing research, with newer supportive strategies emerging (ACCOC, 2025).
• For full clinical details, refer to the Cancer Australia and eviQ clinical guidance resources.

Availability and Delivery

• Pack Sizes: 30-tablet blister pack (25 mg per tablet), some generics available in 90-tablet packs.
• Indicative Price (PBS co-payment): Most eligible patients pay only the standard PBS contribution (approx. $7.30 concession, up to $30 for general patients per pack as of 2024).

*Delivery depends on local pharmacy stocks and postal/courier services. Express options are often available.

FAQ – Frequently Asked Questions

1. Is Aromasin (exemestane) the same as tamoxifen or letrozole?
   No. While all can be used to treat hormone-sensitive breast cancer, Aromasin is a steroidal aromatase inhibitor, whereas tamoxifen is a selective oestrogen receptor modulator, and letrozole is a non-steroidal aromatase inhibitor. Choice depends on your cancer history and tolerance.
2. What should I do if I miss a dose?
   Take it as soon as you remember, unless it is almost time for your next scheduled dose. Never double up doses. Missing one tablet occasionally is unlikely to affect your therapy, but regular missing may reduce effectiveness.
3. Can I still drink alcohol while on Aromasin?
   Light alcohol consumption is usually acceptable, but moderation is best. Heavy drinking can aggravate side effects like tiredness or liver strain.
4. How will Aromasin affect my bone health?
   As with all aromatase inhibitors, long-term use can reduce bone density and increase fracture risk. Your doctor may recommend regular bone scans and suggest calcium/vitamin D supplements or other treatments as needed.
5. Can Aromasin be used in men or children?
   No. It is not approved or typically effective in men or children, except in rare specialist circumstances.

For more personalised advice, discuss your treatment plan with your oncologist, pharmacist, or breast care nurse.