What is Enzalutamide: Uses, Dosage, Side Effects and More

Enzalutamide is a prescription medication specifically designed to treat advanced prostate cancer. It belongs to a class of drugs called androgen receptor inhibitors, which work by blocking testosterone from fueling cancer cell growth.

This medication represents a significant advancement in prostate cancer treatment, offering hope for men whose cancer has spread or become resistant to other hormone therapies. Understanding how enzalutamide works and what to expect can help you feel more confident about your treatment journey.

What is Enzalutamide?

Enzalutamide is an oral cancer medication that targets prostate cancer cells by blocking androgen receptors. Think of it as a key that prevents testosterone from unlocking cancer cell growth and multiplication.

Unlike traditional hormone therapies that reduce testosterone production, enzalutamide takes a different approach. It directly prevents testosterone from binding to cancer cells, essentially starving them of the fuel they need to grow. This makes it particularly effective for cancers that have become resistant to other hormone treatments.

The medication comes in capsule form and is taken by mouth once daily. It's considered a targeted therapy because it specifically attacks the mechanisms that prostate cancer cells use to survive and spread.

What is Enzalutamide Used For?

Enzalutamide is primarily used to treat metastatic castration-resistant prostate cancer and metastatic hormone-sensitive prostate cancer. These are advanced forms of prostate cancer that have either spread to other parts of the body or stopped responding to initial hormone treatments.

Your doctor might recommend enzalutamide if your prostate cancer has progressed despite other treatments. It's often prescribed when cancer has spread to bones, lymph nodes, or other organs, or when your PSA levels continue rising despite hormone therapy.

The medication is also used in combination with other treatments like androgen deprivation therapy. This comprehensive approach helps provide better cancer control and can improve quality of life for many patients.

How Does Enzalutamide Work?

Enzalutamide works by blocking androgen receptors on prostate cancer cells, preventing testosterone from binding and activating cancer growth. It's considered a potent medication that targets cancer cells through three main mechanisms.

First, it prevents testosterone from binding to androgen receptors on cancer cells. Second, it stops these receptors from moving into the cell nucleus where they would normally trigger cancer growth. Third, it blocks the receptors from binding to DNA and activating genes that promote cancer cell multiplication.

This triple-action approach makes enzalutamide particularly effective against aggressive prostate cancers. The medication essentially cuts off multiple pathways that cancer cells use to grow and spread, making it harder for the cancer to find alternative routes for survival.

How Should I Take Enzalutamide?

Take enzalutamide exactly as prescribed by your doctor, typically once daily at the same time each day. You can take it with or without food, but staying consistent with your routine helps maintain steady medication levels in your body.

Swallow the capsules whole with a full glass of water. Don't crush, chew, or open the capsules, as this can affect how the medication is absorbed and may cause side effects. If you have trouble swallowing capsules, talk to your doctor about alternative options.

It's important to take enzalutamide at the same time each day to maintain consistent levels in your bloodstream. Many patients find it helpful to link taking their medication to a daily routine, like having breakfast or brushing teeth, to help remember.

How Long Should I Take Enzalutamide For?

The duration of enzalutamide treatment varies for each person and depends on how well the medication is working and how well you tolerate it. Many patients continue taking it for months or even years as long as it's controlling their cancer effectively.

Your doctor will monitor your response through regular PSA tests, imaging scans, and physical examinations. These help determine whether the medication is working and if you should continue treatment. Some patients may take enzalutamide for extended periods as a maintenance therapy.

Treatment typically continues until the cancer progresses, unacceptable side effects occur, or your doctor determines it's time to try a different approach. Never stop taking enzalutamide without discussing it with your healthcare team first, as this could allow your cancer to grow more quickly.

What Are the Side Effects of Enzalutamide?

Like all cancer medications, enzalutamide can cause side effects, though not everyone experiences them. Most side effects are manageable with proper medical support and lifestyle adjustments.

Let's walk through the most common side effects you might experience, keeping in mind that your medical team is prepared to help you manage any concerns that arise.

Common Side Effects

The most frequently reported side effects affect daily energy and comfort levels. These typically develop gradually and can often be managed with supportive care.

• Fatigue and weakness that may affect daily activities
• Hot flashes similar to those experienced during menopause
• Decreased appetite and potential weight loss
• Joint pain and muscle stiffness
• Headaches that may be mild to moderate
• Dizziness, especially when standing up quickly
• Constipation or changes in bowel habits
• Swelling in legs, ankles, or feet

These side effects often improve as your body adjusts to the medication. Your healthcare team can provide strategies to help manage these symptoms and maintain your quality of life.

Serious Side Effects

While less common, some side effects require immediate medical attention. Being aware of these helps you know when to contact your doctor right away.

• Seizures, which occur in less than 1% of patients
• Severe allergic reactions with difficulty breathing or swelling
• Signs of liver problems like yellowing of skin or eyes
• Severe fatigue that interferes with basic daily activities
• Persistent confusion or memory problems
• Chest pain or difficulty breathing
• Severe dizziness or fainting spells

If you experience any of these symptoms, contact your healthcare provider immediately. Early intervention can often prevent these side effects from becoming more serious.

Rare but Important Side Effects

Some uncommon side effects deserve special attention because they can significantly impact your health if not addressed promptly.

• Posterior reversible encephalopathy syndrome (PRES), a rare brain condition
• Severe skin reactions or rashes
• Blood clotting disorders
• Severe depression or mood changes
• Significant changes in heart rhythm
• Severe muscle weakness or pain

While these side effects are rare, your medical team will monitor you carefully for any signs of these conditions during your treatment.

Who Should Not Take Enzalutamide?

Enzalutamide isn't suitable for everyone, and certain medical conditions or circumstances may make it unsafe. Your doctor will carefully evaluate your medical history before prescribing this medication.

Women who are pregnant or could become pregnant should never take enzalutamide, as it can cause serious harm to developing babies. The medication can also be passed through breast milk, so nursing mothers should avoid it completely.

People with a history of seizures or brain conditions that increase seizure risk may not be good candidates for enzalutamide. Your doctor will also be cautious if you have severe liver or kidney problems, as these conditions can affect how your body processes the medication.

Enzalutamide Brand Names

Enzalutamide is most commonly available under the brand name Xtandi. This is the original brand name under which the medication was first approved and marketed.

Your pharmacy may dispense either the brand name version or a generic equivalent, depending on your insurance coverage and availability. Both versions contain the same active ingredient and work identically in your body.

If you have questions about which version you're receiving or concerns about switching between brand and generic forms, discuss this with your pharmacist or healthcare provider.

Enzalutamide Alternatives

Several other medications work similarly to enzalutamide for treating advanced prostate cancer. These alternatives may be considered if enzalutamide isn't suitable for you or stops working effectively.

Apalutamide (Erleada) and darolutamide (Nubeqa) are newer medications that work through similar mechanisms. Your doctor might also consider abiraterone (Zytiga), which works differently by blocking testosterone production rather than blocking its receptors.

The choice between these medications depends on your specific cancer characteristics, other health conditions, and how well you've responded to previous treatments. Your oncologist will help determine which option might work best for your situation.

Is Enzalutamide Better Than Abiraterone?

Both enzalutamide and abiraterone are effective treatments for advanced prostate cancer, but they work through different mechanisms. Neither is universally "better" than the other, as the best choice depends on your individual circumstances.

Enzalutamide blocks testosterone receptors on cancer cells, while abiraterone reduces testosterone production throughout the body. Some patients respond better to one approach than the other, and your doctor will consider factors like your cancer's characteristics and previous treatments.

Studies have shown both medications can extend survival and improve quality of life. The decision often comes down to side effect profiles, drug interactions, and how well each medication fits with your overall treatment plan.