HOW DO ANTINEOPLASTIC ANTIANDROGENS WORK?

Antineoplastic antiandrogens are a class of drugs used to treat metastatic castration-sensitive prostate cancer (mCSPC) and metastatic castration-resistant prostate cancer (mCRPC) in men. They belong to a class of medications called “androgen receptor inhibitors” that work by blocking the effects of androgen (a male reproductive hormone) to stop the growth and spread of cancer cells.

The predominant and most active androgen is testosterone, which is produced by the male testes. In males, testosterone is responsible for various normal functions, including growth and development of the genitals, muscles, and bones and maintenance of secondary sex characteristics. Testosterone promotes the growth of many prostate tumors, thus reducing circulating testosterone to very low (castration) levels which is often the treatment goal in the management of advanced prostate cancer.

Antineoplastic antiandrogens are administered as a powder to be mixed with liquid and injected under the skin in the stomach area, away from the ribs and waistline once every 28 days, and orally with or without food.

Antineoplastic antiandrogens work in the following ways:

• They belong to a class of medications called “androgen receptor inhibitors” that work by blocking the effects of androgen (a male reproductive hormone) to stop the growth and spread of cancer cells.
• They help in reducing the amount of testosterone, thereby slowing the growth and spread of prostate cancer.
• They bind to gonadotropin-releasing hormone (GnRH) receptors in the pituitary gland and block their interaction with GnRH which further induces a fast reduction in luteinizing hormone and follicle-stimulating hormone, and in turn, testosterone suppression. 
• In addition, they belong to a class of medications called “androgen biosynthesis inhibitors” that work by decreasing the number of certain hormones in the body.

Antineoplastic antiandrogens are used to treat mCSPC and mCRPC in men.

Some of the common side effects include:

• Nausea
• Vomiting
• Mild rash
• Dry skin
• Diarrhea
• Abdominal pain
• Headache
• Hot flashes
• Tiredness/weakness
• Back/joint pain
• Constipation
• Taste changes
• Loss of sexual interest
• Loss of appetite
• Pain, redness, swelling, hardness, or itching at the injection site

Other rare side effects include:

• Dizziness 
• Breast enlargement in men
• 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)
• Hyperkalemia (high blood potassium level)
• Shortness of breath
• Excessive sweating
• Chills, sore throat, fever, or cough
• Painful or difficult urination

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 antiandrogens include:

• Abiraterone
• Apalutamide
• Bicalutamide
• Casodex
• Degarelix
• Enzalutamide
• Erleada
• Firmagon
• Flutamide
• Nilandron
• Nilutamide
• Xtandi
• Yonsa
• Zytiga