Products
Exemestane is commercially available in the form of dragées and film-coated tablets (Aromasin, generics). It has been approved in many countries since 1999.
Structure and properties
Exemestane (C20H24O2, Mr = 296.4 g/mol), unlike other aromatase inhibitors, has a steroidal structure and resembles the natural substrate androstenedione. It exists as a white to slightly yellowish crystalline powder that is practically insoluble in water.
Effects
Exemestane (ATC L02BG06) has antiestrogenic and antitumor properties. The effects are due to irreversible inhibition of aromatase. Inhibition of this enzyme lowers estrogen levels in the circulation, making less hormone available to tumor cells for growth. Other aromatase inhibitors reversibly inhibit the enzyme.
Indications
For adjunctive treatment of postmenopausal women with breast cancer.
Abuse
Exemestane is abused in bodybuilding and as a doping agent.
Dosage
According to the SmPC. The tablets can be taken once daily due to their long half-life and duration of action. They are administered after a meal and always at the same time of day.
Contraindications
- Hypersensitivity
- Before premenopause
- Pregnancy and lactation
Full precautions can be found in the drug label.
Interactions
Exemestane is metabolized by CYP3A4 and aldoketoreductases. Estrogens may abolish the effects.
Adverse effects
Adverse effects are largely due to estrogen withdrawal and therefore resemble menopausal symptoms. The most common possible adverse effects include flushing, fatigue, headache, sleep disturbances, increased sweating, nausea, and joint and skeletal muscle pain.
