Antiandrogens: Uses, common brands, and safety info

Antiandrogens are a class of drugs that block the effects of androgens, or male hormones, in the body. Androgens like testosterone may be higher in some people than in others, and higher levels are often associated with certain medical conditions like prostate cancer in men and polycystic ovary syndrome (PCOS) in women. The most common antiandrogen drugs work as androgen receptor (AR) antagonists that prevent androgens like testosterone from binding to androgen receptors. By binding to these receptors and blocking androgen receptors, AR antagonists can help treat androgen-dependent conditions. 

Continue reading to learn more about antiandrogens, their side effects, and how they work.

Other antiandrogens

• Abiraterone acetate

• Androcur (cyproterone acetate)

• Megace (megestrol acetate)

• Proscar (finasteride)

•  Avodart (dutasteride)

What are antiandrogens?

Antiandrogens are a group of medications that block the actions of the male sex hormones, testosterone, and dihydrotestosterone (DHT). These medications can be used for various purposes in men, such as the treatment of prostate cancer, benign prostatic hyperplasia (BPH), pattern hair loss, priapism, and hypersexuality. In women, antiandrogens may be used to treat acne, excessive hair growth (hirsutism), polycystic ovary syndrome (PCOS), ovarian tumors, and adrenal gland tumors. Antiandrogens may also be used as a form of feminizing hormone therapy in transgender women.  

Also known as a specific form of hormone therapy, antiandrogens may be prescribed as part of an initial treatment regimen for metastatic prostate cancer. Antiandrogens are not generally used alone. Instead, they can be used along with a luteinizing hormone-releasing hormone (LHRH) agonist for combined androgen blockade in metastatic prostate cancer. LHRH agonists, sometimes called gonadotropin-releasing hormone (GnRH) agonists, are a form of medical castration to lower androgen levels. Clinical trials have found that combined treatment with antiandrogens can improve the overall survival rate of advanced prostate cancer patients rather than using castration alone. 

Antiandrogens, like flutamide and bicalutamide, are generally administered as an oral tablet or capsule. 

How do antiandrogens work?

Antiandrogens primarily work by blocking the ability of testosterone and DHT to bind with androgen receptors. As a result, antiandrogens block the effects of these male sex hormones, which are often involved with the stimulation of prostate cancer cells and the symptoms of other health conditions. Androgens promote the growth of prostate cancer cells, and around 80 to 90% of prostate cancers at initial diagnosis need androgens for growth. Treatment for this type of cancer typically involves blocking the effects of testosterone. 

Other drugs can also have antiandrogen effects. Certain drugs can decrease testosterone levels by blocking the synthesis, or production, of androgens. These drugs can disrupt the enzyme needed to produce androgens, which directly lowers androgen levels. Other drugs can block testosterone production in the testes or the adrenal glands. 

What are antiandrogens used for?

Antiandrogens are used to treat various medical and health conditions. They may also be used in transgender women.  Here are some conditions they treat:

• Prostate cancer

• Benign prostatic hyperplasia

• Alopecia

• Priapism

• Hypersexuality

• Polycystic ovary syndrome (POCS)

• Hirsutism

• Adrenal gland tumors

• Feminizing hormone therapy

Types of antiandrogens 

Antiandrogens are typically divided into two main groups: steroidal and nonsteroidal antiandrogens. However, other medications also have antiandrogen effects. 

Steroidal antiandrogens

Steroidal antiandrogens have a chemical structure similar to that of steroid hormones. As a result, these antiandrogens can also bind to other steroid receptors, which can lead to adverse effects. They have been largely replaced by nonsteroidal antiandrogens for the treatment of prostate cancer. Steroidal antiandrogens include cyproterone acetate and spironolactone. The progesterone analogs mifepristone and megestrol acetate are also examples of steroidal antiandrogens. 

Nonsteroidal antiandrogens

Nonsteroidal antiandrogens have stronger selectivity for androgen receptors and thus, they are sometimes called pure antiandrogens. These antiandrogens are known to have less nonspecific side effects that are often associated with steroidal antiandrogens. Examples of nonsteroidal antiandrogens include flutamide and bicalutamide. Nilutamide is another nonsteroidal antiandrogen that is a derivative of flutamide. 

Androgen synthesis inhibitors 

Certain medications can inhibit the biosynthesis of androgens. Ketoconazole and abiraterone acetate are examples of CYP17A1 inhibitors that can block androgen production. Finasteride and dutasteride are examples of 5-alpha reductase inhibitors that block that enzyme responsible for converting testosterone into DHT. Finasteride is commonly prescribed for BPH and male pattern hair loss. 

Who can take antiandrogens?

Adults

In both men and women, androgen levels can be high and contribute to androgen-dependent medical conditions. Antiandrogen therapy may be prescribed for prostate cancer, benign prostatic hyperplasia, or pattern hair loss in men or polycystic ovary syndrome, hirsutism, or ovarian tumors in women. They may also be prescribed to transgender women to reduce masculine sex characteristics. Antiandrogens are typically taken on a daily basis, depending on the medication and strength prescribed. The duration of treatment depends on the condition being treated. 

Seniors 

There are no specific dosing considerations that need to be taken into account for older adults. However, seniors may need to be monitored while on antiandrogen treatment, especially if they have liver, kidney, or heart problems. Nonsteroidal antiandrogens may be considered for seniors with advanced prostate cancer as a form of hormone therapy. 

Children 

Antiandrogens are sometimes prescribed to treat precocious puberty in boys. They can help delay the onset of secondary sexual characteristics like facial and body hair until a more appropriate age. Antiandrogens may also be prescribed to prevent puberty in transgender girls until they are old enough to receive hormone therapy.  

Are antiandrogens safe?

Antiandrogens are generally safe when used appropriately. Nonsteroidal antiandrogens are usually preferred over other antiandrogens due to their high efficacy rate and improved safety and tolerability. Antiandrogenic side effects depend on the type and dosage of medication prescribed, and side effects are usually mild and go away on their own. Consult a healthcare provider for full advice on the safety and effectiveness of antiandrogen medications for your specific condition. 

Recalls

There are currently no recalls initiated for antiandrogens.

Restrictions

Talk to your doctor about any medical conditions you may have before starting treatment with an antiandrogen. Tell your doctor if you have a history of liver disease, lung disease, or diabetes before taking an antiandrogen.

Tell your doctor if you are pregnant or breastfeeding before starting treatment with an antiandrogen. These medications may cause potential harm to an unborn baby or transfer into breast milk. 

Your doctor should know about any medications you may be taking, including prescription medications, over-the-counter medicines, and herbal supplements. Tell your doctor if you are taking any hormonal contraceptives before starting antiandrogen treatment. 

Alcohol use can cause damage to the liver and increase the risk of liver toxicity from antiandrogens. Consult a healthcare provider for medical advice on the use of alcohol while taking an antiandrogen. 

You should not take an antiandrogen if you have a hypersensitivity to any ingredients in the medication. Seek immediate medical attention if you experience signs of an allergic reaction, such as severe rash, hives, swelling, or trouble breathing. 

Are antiandrogens controlled substances?

No, antiandrogens are not controlled substances.

Common antiandrogens side effects

Common side effects of antiandrogens include the following:

• Hot flashes

• Breast enlargement

• Breast tenderness

• Infertility 

• Reduced sex drive 

• Erectile dysfunction, or impotence

• Testicular atrophy

• Osteoporosis

• Anemia

• Weight gain

• Fatigue

• Increased body fat

• Depression

• Decreased muscle mass

• Decreased body hair

The type and severity of side effects experienced vary depending on the drug prescribed. Side effects are associated with decreased levels and effects of androgens like testosterone. Side effects may be more tolerated in women than in men, although women can experience adverse effects from low estrogen levels, such as changes in menstruation and hot flashes. 

Serious side effects of nonsteroidal antiandrogens include liver damage and liver failure. Liver enzyme levels may need to be monitored during the first few months of treatment. Caution should be used when starting treatment with a nonsteroidal antiandrogen if liver function is a concern. 

Antiandrogens can cause gynecomastia, or breast enlargement in men, as a result of their androgen antagonist actions on the mammary glands. Gynecomastia can occur in up to 75% of men on antiandrogen treatment. Tamoxifen or radiation therapy may help prevent the incidence of gynecomastia in men taking antiandrogens. 

Changes in blood sugar levels may develop in those on antiandrogens in combination with an LHRH agonist. Blood sugar levels may need to be monitored in certain people taking combined androgen blockade therapy. 

How much do antiandrogens cost?

Antiandrogens are available in both brand and generic forms. Medicare and prescription insurance plans may help cover the cost of antiandrogen treatment. Talk to your insurance company or pharmacist to determine the exact cost of your medication with insurance. The average cash price of antiandrogens may be high depending on the strength, quantity, and type of medication prescribed. Savings options, like the SingleCare prescription discount card, are available to help lower the cost of medications. This discount card can be used by both insured and uninsured patients who are looking to save money on their prescription medications.