Zytiga Drug Interactions: What You Need to Know

If you're taking Zytiga (Abiraterone Acetate) for prostate cancer, it's important to know that certain medications, supplements, and even foods can interact with your treatment. Some interactions can make Zytiga less effective, while others can increase the risk of side effects.

This guide covers the most important Zytiga drug interactions and what to tell your doctor before starting treatment.

How Drug Interactions Work with Zytiga

Zytiga is processed by your liver, and it also affects how your liver processes other drugs. Specifically, Abiraterone Acetate:

• Inhibits CYP2D6 — An enzyme that breaks down many common medications. When Zytiga blocks this enzyme, those medications can build up to higher-than-normal levels in your body.
• Inhibits CYP2C8 — Another liver enzyme involved in processing certain drugs.
• Is affected by CYP3A4 inducers — Drugs that speed up CYP3A4 enzyme activity can break down Abiraterone faster, reducing its effectiveness.

Understanding these pathways helps explain why certain combinations are risky.

Medications That Interact with Zytiga

Medications Processed by CYP2D6 (Use with Caution)

Because Zytiga inhibits CYP2D6, the following types of medications may reach higher levels in your body than expected:

• Dextromethorphan — Found in many over-the-counter cough medicines (Robitussin, DayQuil, NyQuil). Higher levels can cause dizziness or other side effects.
• Thioridazine — An antipsychotic. Increased levels can cause serious heart rhythm problems. Avoid this combination.
• Certain antidepressants — Some SSRIs and other antidepressants are metabolized by CYP2D6. Your doctor may need to adjust doses.
• Codeine and Tramadol — These pain medications are converted to their active forms by CYP2D6. Interaction with Zytiga may affect how well they work.
• Some beta-blockers — Like Metoprolol, which is used for blood pressure and heart conditions.

Medications Processed by CYP2C8 (Use with Caution)

• Pioglitazone — A diabetes medication. Zytiga can increase its levels, raising the risk of side effects.

Strong CYP3A4 Inducers (May Reduce Zytiga's Effectiveness)

These medications can speed up how quickly your body breaks down Zytiga, potentially making it less effective:

• Rifampin — An antibiotic used for tuberculosis
• Phenytoin — A seizure medication
• Carbamazepine — Another seizure medication

If you need any of these medications, your doctor will weigh the risks and may consider alternative treatments.

Spironolactone (Avoid)

Spironolactone is a blood pressure and heart failure medication that can increase androgen levels. Since Zytiga works by lowering androgens, taking Spironolactone at the same time could work against your cancer treatment. Avoid this combination.

Supplements and Over-the-Counter Products

Don't assume that "natural" means safe with Zytiga. Several common supplements and OTC products can interact:

• St. John's Wort — This herbal supplement is a strong CYP3A4 inducer. It can significantly reduce Zytiga levels in your body, making the cancer treatment less effective. Do not take St. John's Wort while on Zytiga.
• Cough and cold medicines containing dextromethorphan — As mentioned above, Zytiga can increase DXM levels. Check labels carefully and ask your pharmacist for alternatives.
• Potassium supplements — Zytiga can cause low potassium, and your doctor may prescribe supplements. This isn't an interaction to avoid — it's something your doctor will manage through monitoring.

Always tell your doctor about every supplement, vitamin, and herbal product you take — even if it seems harmless.

Food and Drink Interactions

The most important food interaction with Zytiga is simple but critical:

Take Zytiga on an Empty Stomach

Do not take Zytiga with food. Eating within an hour before or two hours after taking Zytiga dramatically increases absorption — by up to 10 times for a high-fat meal. This can lead to dangerously high drug levels and increased side effects including liver toxicity.

• Take Zytiga at least 1 hour before or 2 hours after eating
• Swallow tablets whole with water
• Do not crush, chew, or break the tablets

Note: The Yonsa formulation of Abiraterone Acetate uses a different technology and can be taken with or without food. Make sure you know which product you're taking.

For complete dosing instructions, see our guide on what Zytiga is and how to take it.

Alcohol

While there's no specific interaction listed between Zytiga and alcohol, both Zytiga and alcohol are processed by the liver. Since Zytiga can cause liver damage, your doctor may recommend limiting or avoiding alcohol during treatment.

What to Tell Your Doctor

Before starting Zytiga, give your doctor a complete list of:

• All prescription medications you take, including those prescribed by other doctors
• Over-the-counter medications — pain relievers, cough medicines, antacids, allergy medications
• Herbal supplements and vitamins — especially St. John's Wort
• Medical conditions — particularly liver disease, heart problems, or adrenal gland issues

Keep an updated medication list and bring it to every appointment. If any doctor (not just your oncologist) wants to prescribe a new medication, remind them that you're taking Zytiga.

Your pharmacist is also a valuable resource. They can check for interactions whenever you pick up a new prescription or OTC product.

Final Thoughts

Drug interactions with Zytiga are manageable as long as you and your care team are aware of them. The most important things to remember: avoid St. John's Wort and Spironolactone, take Zytiga on an empty stomach, and always tell your doctors about every medication and supplement you use.

For more information, explore our guides on Zytiga side effects and how Zytiga works. If you need help finding Zytiga at a pharmacy, Medfinder can help you locate it in stock near you.