How Do Antineoplastic Aromatase Inhibitors Work?

Antineoplastic aromatase inhibitors are a class of drugs used to treat hormone receptor-positive breast cancer in women who have experienced menopause (end of monthly menstrual periods) in combination with other treatments, such as surgery or radiation therapy.

Estrogen is a sex hormone produced primarily by the ovaries and a small amount by the adrenal glands and fat tissues, which is responsible for the development and regulation of the female reproductive system and secondary sex characteristics. Aromatase inhibitors are used as a type of hormone therapy for postmenopausal women who have hormone-dependent breast cancer which works by lowering the estrogen levels by preventing the enzyme "aromatase" in fat tissues from converting other hormones into estrogen which can fuel the growth of breast cancer cells.

Aromatase inhibitors are administered orally once a day with or without food, typically around the same time every day.

Aromatase inhibitors work in the following ways:

• They work by decreasing or lowering the amount of estrogen produced by the body which helps to slow down or stop the growth of breast tumors (hormone-positive tumors) that require estrogen to grow and spread.
• This inhibition helps in reducing the amount of estrogen available for stimulating the growth of hormone receptor-positive breast cancer cells.
• In addition, they either block the production of estrogen or block the action of estrogen on receptors.

Antineoplastic aromatase inhibitors are used as initial endocrine-based therapy for the treatment of pre/perimenopausal or postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced or metastatic breast cancer.

Some of the common side effects include:

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Heartburn
• Headache
• Hot flushes
• Tiredness/weakness
• Bone/joint/muscle pain
• Constipation
• Increased/decreased appetite

Other rare side effects include:

• Dizziness 
• Unusual sweating
• Fatigue 
• Weight loss
• Hair loss
• Blurry vision
• Swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• Insomnia (trouble falling and/or staying asleep)
• Hypertension (high blood pressure)
• Shortness of breath
• Chest pain
• Bone fractures
• Mood disturbances
• Chills, sore throat, fever, or cough

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of antineoplastic aromatase inhibitors include:

• Anastrozole
• Arimidex
• Aromasin
• Exemestane
• Femara
• Kisqali/femara copack
• Letrozole
• Ribociclib/letrozole