Aromasin (exemestane) is a potent, steroidal aromatase inactivator indicated for the treatment of estrogen receptor-positive early and advanced breast cancer in postmenopausal women. As a third-generation aromatase inhibitor, it works by irreversibly binding to the aromatase enzyme, leading to a significant and sustained reduction in circulating estrogen levels—a key driver in hormone-sensitive tumor growth. Its unique mechanism of action and well-established efficacy profile make it a cornerstone in adjuvant and metastatic settings, offering a targeted approach to hormonal manipulation with a predictable safety spectrum. Clinical evidence supports its role in extending disease-free survival and reducing contralateral breast cancer incidence.

Features

• Contains exemestane 25 mg as the active pharmaceutical ingredient
• Steroidal, irreversible aromatase inactivator (type I inhibitor)
• Oral tablet formulation for once-daily administration
• High selectivity for aromatase enzyme with minimal effect on adrenal steroidogenesis
• Demonstrated bioavailability of approximately 42% following oral administration
• Extensive tissue distribution with plasma protein binding of approximately 90%
• Metabolized primarily by CYP 3A4 isoenzyme
• Mean elimination half-life of approximately 24 hours

Benefits

• Significantly reduces estrogen synthesis by permanently inactivating the aromatase enzyme
• Demonstrated improvement in disease-free survival in adjuvant treatment of early breast cancer
• Proven efficacy in advanced breast cancer following failure of tamoxifen therapy
• Lower risk of endometrial abnormalities compared to selective estrogen receptor modulators
• Favorable lipid profile compared to non-steroidal aromatase inhibitors
• May preserve bone mineral density better than some alternative endocrine therapies

Common use

Aromasin is primarily prescribed for the treatment of estrogen receptor-positive breast cancer in postmenopausal women. In the adjuvant setting, it is used following 2-3 years of tamoxifen therapy to complete a total of 5 years of adjuvant endocrine treatment. For advanced breast cancer, it is indicated in women whose disease has progressed following tamoxifen therapy. The medication is also used in neoadjuvant settings and occasionally off-label for estrogen suppression in fertility treatments and gynecomastia prevention, though these uses lack robust regulatory approval.

Dosage and direction

The recommended dosage of Aromasin is one 25 mg tablet taken orally once daily after a meal. Administration with food enhances drug absorption and consistency. Treatment should continue until tumor progression is documented in advanced disease settings. For adjuvant therapy, treatment duration is typically 2-3 years following initial tamoxifen therapy, completing a total of 5 years of endocrine treatment. Dose adjustment is not necessary for elderly patients or those with mild to moderate hepatic impairment. For patients with severe hepatic impairment, consideration of alternative therapy is recommended.

Precautions

Regular monitoring of bone mineral density is recommended due to potential acceleration of bone loss. Assessment of lipid profiles should be conducted periodically, particularly in patients with pre-existing hyperlipidemia. Patients should be advised about potential effects on driving and operating machinery due to reported fatigue and dizziness. Caution is advised in patients with pre-existing cardiovascular risk factors. Vitamin D and calcium supplementation should be considered to mitigate bone health effects. Regular follow-up including appropriate imaging studies is essential to monitor treatment response.

Contraindications

Aromasin is contraindicated in women who are premenopausal, pregnant, or breastfeeding. It must not be used in patients with known hypersensitivity to exemestane or any component of the formulation. Concomitant use with estrogen-containing medications is contraindicated. The medication is not indicated for pediatric use. Patients with severe hepatic impairment (Child-Pugh Class C) should generally avoid this medication due to limited safety data. Those with significantly compromised renal function (creatinine clearance <30 mL/min) require careful risk-benefit assessment before initiation.

Possible side effects

The most frequently reported adverse reactions include hot flashes (approximately 25%), fatigue (16%), arthralgia (15%), and headache (13%). Musculoskeletal pain and stiffness affect approximately 13% of patients. Gastrointestinal disturbances such as nausea (12%) and increased sweating (11%) are commonly observed. Less frequent but clinically significant effects may include osteoporosis (approximately 10%), insomnia (9%), dizziness (8%), and carpal tunnel syndrome (3%). Laboratory abnormalities may include elevated liver enzymes and mild lipid profile changes. Serious but rare adverse events include Stevens-Johnson syndrome and anaphylactic reactions.

Drug interaction

Strong CYP3A4 inducers such as rifampicin, phenytoin, and St. John’s Wort may significantly reduce exemestane concentrations, potentially compromising efficacy. Concomitant use with estrogen-containing therapies may antagonize the therapeutic effect. Caution is advised with medications that affect bone metabolism, including corticosteroids and certain anticonvulsants. The potential for interactions with warfarin requires careful INR monitoring. Although formal studies are limited, concomitant use with other agents metabolized by CYP isoenzymes warrants vigilance. Healthcare providers should review all concomitant medications, including herbal supplements.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, the missed dose should be skipped, and the regular dosing schedule resumed. Doubling the dose to make up for a missed dose is not recommended. Patients should be educated to maintain a consistent dosing time, preferably with the evening meal, to enhance compliance and absorption consistency. If multiple doses are missed, medical advice should be sought regarding continuation of therapy.

Overdose

There is limited experience with Aromasin overdose. Single doses up to 800 mg have been administered without severe adverse effects. In case of suspected overdose, symptomatic and supportive care is recommended. Gastric lavage may be considered if ingestion occurred within a short timeframe. Since exemestane is highly protein-bound, dialysis is unlikely to be effective. Monitoring of vital signs and appropriate symptomatic management should be instituted. There is no specific antidote for exemestane overdose. Medical toxicology consultation is advised in significant overdose situations.

Storage

Store at room temperature between 20°C to 25°C (68°F to 77°F) with excursions permitted between 15°C to 30°C (59°F to 86°F). Keep in the original container with the lid tightly closed to protect from moisture and light. Do not store in bathroom areas where humidity fluctuations occur. Keep out of reach of children and pets. Do not use beyond the expiration date printed on the packaging. Properly dispose of any unused medication through take-back programs or according to local regulations.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Individual patient circumstances may vary, and healthcare provider consultation is essential before initiating or modifying any treatment regimen. The prescribing physician should be consulted for specific dosage recommendations and therapeutic decisions. Actual product characteristics and prescribing information may vary by jurisdiction. Patients should report any adverse effects to their healthcare provider and refer to the local package insert for comprehensive safety information.

Reviews

Clinical trials demonstrate Aromasin’s efficacy with a hazard ratio of 0.68 for disease-free survival compared to continued tamoxifen in the adjuvant setting. The Intergroup Exemestane Study showed a 4.7% absolute improvement in 5-year disease-free survival. In advanced disease, response rates of approximately 15-25% have been observed following tamoxifen failure. Patient-reported outcomes indicate manageable side effect profiles, though individual tolerance varies. Long-term follow-up data confirm sustained efficacy with appropriate management of metabolic consequences. The medication maintains a favorable benefit-risk profile in appropriately selected patient populations.