Verzenio (abemaciclib) is a prescription drug that treats breast cancer in certain situations. This drug can interact with other medications and some supplements. For example, Verzenio can interact with St. John’s wort and ketoconazole.
Verzenio is used in adults to treat certain forms of breast cancer that are hormone receptor-positive (HR-positive) and HER2-negative. Specifically, these are:
- early breast cancer that has spread to lymph nodes and has a high risk of coming back; it’s used along with hormone therapy
- advanced or metastatic breast cancer; as a first treatment, it’s used along with an aromatase inhibitor such as anastrozole (“Advanced” means it might be managed but may not be curable. “Metastatic” means the cancer has spread from the breast to other parts of the body.)
- advanced or metastatic breast cancer that progresses (worsens or comes back) following hormone therapy; it’s used along with the drug fulvestrant
- advanced or metastatic breast cancer that progresses (worsens or comes back) following hormone therapy and chemotherapy
The active ingredient in Verzenio is abemaciclib. It comes in oral tablets.
An interaction can occur because one substance causes another substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.
Keep reading to learn about Verzenio’s possible interactions. And for more information about Verzenio, including details about its uses, see this article.
Before you start taking Verzenio, tell your doctor and pharmacist about any prescription, over-the-counter, or other drugs you take. Sharing this information with them may help prevent possible interactions. (To learn whether Verzenio interacts with herbs or vitamins and supplements, see the “Are there other interactions with Verzenio?” section below.)
If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.
The table below lists drugs that may interact with Verzenio. Keep in mind that this table does not include all drugs that may interact with Verzenio. For more information about some of these interactions, see the “Drug interactions explained” section below.
| Drug group or drug name | Drug examples | What can happen |
|---|---|---|
| certain anti-androgen medications | • apalutamide (Erleada) • enzalutamide (Xtandi) | can make Verzenio less effective |
| certain antiepileptic drugs | • carbamazepine (Tegretol, others) • phenytoin (Dilantin) • primidone | can make Verzenio less effective |
| certain antifungal drugs | • ketoconazole • posaconazole (Noxafil) • voriconazole (Vfend) • itraconazole (Sporanox, Tolsura) | can increase the risk of side effects with Verzenio |
| certain heart medications | • diltiazem (Cardizem, others) • verapamil (Verelan, others) | can increase the risk of side effects with Verzenio |
| cobicistat and medications that contain it | • Genvoya (elvitegravir/cobicistat/ emtricitabine/tenofovir alafenamide) • Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate) | can increase the risk of side effects with Verzenio |
| ritonavir and medications that contain it | • Paxlovid (nirmatrelvir/ritonavir) • Kaletra (lopinavir/ritonavir) | can increase the risk of side effects with Verzenio |
| clarithromycin | — | can increase the risk of side effects with Verzenio |
| rifampin (Rimactane) | — | can make Verzenio less effective |
Verzenio is not known to interact with alcohol. But Verzenio and alcohol both can cause some similar side effects, such as diarrhea and nausea. So you may be more likely to experience them if you drink alcohol during your Verzenio treatment.
If you have questions about consuming alcohol while taking Verzenio, talk with your doctor or pharmacist.
Learn more about certain drug interactions that can occur with Verzenio.
Interaction with certain antifungal drugs
Verzenio can interact with certain antifungal drugs, which treat infections caused by fungus.
Examples of antifungal medications that interact with Verzenio include:
- ketoconazole
- posaconazole (Noxafil)
- voriconazole (Vfend)
- itraconazole (Sporanox, Tolsura)
What could happen
The antifungal drugs above block an enzyme called CYP3A4. (“CYP” represents cytochrome P450.) This enzyme works to break down some medications after you take a dose, including Verzenio. So blocking CYP3A4 can increase the amount of Verzenio in your system. This doesn’t make Verzenio work better and can raise your risk of side effects from it.
What you can do
According to the drugmaker, you should not take Verzenio along with ketoconazole. It also recommends avoiding taking Verzenio with the other drugs listed above if possible.
If you take Verzenio with one of these drugs, your doctor may prescribe a lowered Verzenio dosage. You should not take a dose of either medication that’s higher than your doctor prescribes.
If you have questions about taking Verzenio with antifungal drugs, talk with your doctor or pharmacist.
Interaction with certain antiepileptic drugs
Verzenio can interact with certain antiepileptic drugs, which treat epilepsy. Some are also used to treat other conditions, such as nerve pain.
Examples of antiepileptic medications that can interact with Verzenio include:
- carbamazepine (Tegretol, others)
- phenytoin (Dilantin)
- primidone
What could happen
The antiepileptic drugs above increase the activity of the CYP3A4 enzyme. (“CYP” represents cytochrome P450.) This enzyme helps break down Verzenio after you take a dose. An increase in this CYP3A4 activity decreases the amount of Verzenio in your body. In turn, this may cause Verzenio not to work or not to work as well.
What you can do
The drugmaker recommends avoiding taking Verzenio with the antiepileptic drugs above. Instead, talk with your doctor about alternative treatments for epilepsy that don’t interact with Verzenio. Your doctor may discuss other treatments for your cancer besides Verzenio. But they likely won’t prescribe these medications together.
Interaction with certain heart medications
Verzenio can interact with the heart medications diltiazem and verapamil. These drugs treat certain arrhythmias and other heart conditions.
What could happen
Verapamil and diltiazem block the actions of the CYP3A4 enzyme. (“CYP” represents cytochrome P450.) This enzyme helps break down Verzenio after you take a dose. So blocking the enzyme can increase the amount of Verzenio in your body. In turn, this raises your risk of side effects from Verzenio.
What you can do
If you take Verzenio with diltiazem or verapamil, your doctor may prescribe a lowered Verzenio dosage. You should not take a dose of either medication that’s higher than your doctor prescribes.
Verzenio may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that the information below does not include all other interactions possible with Verzenio.
Does Verzenio interact with supplements?
Before you start taking Verzenio, talk with your doctor and pharmacist about any herbs or vitamins and supplements you take. Sharing this information with them may help you avoid possible interactions.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Verzenio interactions with herbs
Verzenio can interact with St. John’s wort, which helps manage symptoms of depression. St. John’s wort can lower the amount of Verzenio in your system. This could make Verzenio less effective.
For this reason, it’s important to check with your doctor or pharmacist before taking this product with Verzenio. Your doctor likely will advise that you do not take St. John’s wort while taking Verzenio.
Verzenio and vitamins
Verzenio currently has no reports of interacting with vitamins. But this doesn’t mean that vitamin interactions won’t be recognized in the future.
For this reason, it’s important to check with your doctor or pharmacist before taking any of these products with Verzenio.
Does Verzenio interact with food?
Grapefruit and grapefruit juice can interact with Verzenio. Grapefruit can increase the level of Verzenio in your system, which can raise your risk of side effects.
For this reason, it’s important to check with your doctor or pharmacist about what foods to avoid while taking Verzenio. They’ll likely suggest you avoid consuming grapefruit or grapefruit juice if they prescribe Verzenio for you.
Does Verzenio interact with vaccines?
You should not receive live vaccines during treatment with immunosuppressants like Verzenio. Live vaccines contain weakened versions of the bacteria or virus that they’re meant to protect against. Examples of live vaccines include measles, mumps, rubella (MMR), yellow fever, varicella, and cholera. Your body may not respond or respond as well to these vaccines if you’re taking Verzenio. This means the vaccines may not protect you against the intended germ.
If you have questions about getting certain vaccines during your Verzenio treatment, talk with your doctor.
Does Verzenio interact with lab tests?
Verzenio currently has no reports of interacting with lab tests. If you have questions about having certain lab tests during your treatment with Verzenio, talk with the healthcare professional ordering the test.
Does Verzenio interact with cannabis or CBD?Verzenio currently has no reports of interacting with cannabis (commonly called marijuana) or cannabis products such as cannabidiol (CBD). But as with any drug or supplement, talk with your doctor before using cannabis with Verzenio.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Certain medical conditions or other health factors may raise the risk of interactions with Verzenio. Before taking Verzenio, talk with your doctor about your health history. They’ll determine whether Verzenio is right for you.
Health conditions or other factors that might interact with Verzenio include:
Active infection: If you have an active infection, your doctor may treat it prior to starting your treatment with Verzenio. It’s possible that Verzenio can weaken your immune system and make infections harder to treat.
History of blood clots: Rarely, Verzenio can cause blood clots that may be life threatening. If you’ve ever had a blood clot, it isn’t known whether this risk is higher by taking Verzenio. Talk with your doctor about the risks and benefits of taking Verzenio.
Lung or breathing problem: Verzenio treatment rarely causes side effects of the lungs, such as interstitial lung disease. If you have a lung or breathing problem, such as asthma, you may be at higher risk of these side effects. It’s also possible that Verzenio could worsen symptoms of your lung or breathing problem. Your doctor can discuss whether Verzenio is safe for you to take.
Severe kidney or liver problem: Talk with your doctor before taking Verzenio if you have a severe kidney problem or liver problem. Examples include cirrhosis and end stage kidney disease. If you have a severe kidney problem, it’s not known whether it’s safe to take Verzenio. If you have a severe liver problem, your doctor may prescribe a lowered Verzenio dosage.
Pregnancy: It’s not known whether Verzenio is safe to take during pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor before taking Verzenio.
Breastfeeding: Breastfeeding while taking Verzenio is not recommended. You should avoid breastfeeding for at least 3 weeks after your last Verzenio dose. If you’re breastfeeding or planning to breastfeed, talk with your doctor about your options.
Allergic reaction: If you’ve had an allergic reaction to Verzenio or any of its ingredients, your doctor likely won’t prescribe Verzenio. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.
Taking certain steps can help you avoid interactions with Verzenio. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:
- Whether you drink alcohol or use cannabis.
- Other medications you take, as well as any vitamins, supplements, and herbs. Your doctor or pharmacist can help you fill out a
medication list . - What to do if you start taking a new drug during your Verzenio treatment.
It’s also important to understand Verzenio’s
If you have difficulty reading or understanding this information, your doctor or pharmacist can help.
Taking Verzenio exactly as prescribed also can help prevent interactions.
If you still have questions about Verzenio and its possible interactions, talk with your doctor.
Questions you may want to ask your doctor include:
- Does my risk of interactions with Verzenio depend on my dosage?
- Do other drugs that could treat my condition have similar interactions?
- If I take Verzenio and have certain health conditions, will I be monitored more closely during treatment?
To learn more about Verzenio, see these articles:
- All About Verzenio
- Side Effects of Verzenio: What You Need to Know
- Dosage Details for Verzenio
- Verzenio and Cost: What You Need to Know
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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.