Camzyos (mavacamten) is a brand-name oral capsule that’s prescribed for obstructive hypertrophic cardiomyopathy. Camzyos has interactions with some other drugs and certain supplements. Examples include fluoxetine (Prozac) and omeprazole (Prilosec).

An interaction occurs when one substance causes another substance to have a different effect than expected.

To learn more about Camzyos’s interactions, keep reading. For additional information about Camzyos, including details about its uses, see this article.

Camzyos can interact with drugs that affect the action of certain enzymes in your body. Specifically, it can interact with drugs that affect enzymes called cytochrome P450 3A4 (CYP3A4) and cytochrome P450 2C19 (CYP2C19). These enzymes help clear Camzyos from your body.

Camzyos can interact with drugs that inhibit (reduce the action of) or induce (increase the action of) CYP3A4 and CYP2C19. It can also interact with other drugs that are broken down by these enzymes.

Your doctor and pharmacist can check whether medications that you take can affect or are broken down by these enzymes. Before you start treatment with Camzyos, tell your doctor and pharmacist which prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist. To learn whether Camzyos interacts with supplements, herbs, or vitamins, see the “Camzyos and other interactions” section below.

Here’s a table of drugs that can interact with Camzyos. Keep in mind that this table doesn’t include all drugs that may interact with Camzyos. Some of these interactions are described in detail just below in “Drug interactions in depth.”

Drug group or drug nameDrug examplesInteraction result with Camzyos
strong CYP3A4 inhibitors*• clarithromycin
• itraconazole (Sporanox)
• ritonavir (Norvir)
• nefazodone
can increase the risk of side effects of Camzyos
strong or moderate CYP2C19 inhibitors*• cimetidine (Tagamet HB)
• esomeprazole (Nexium)
fluconazole (Diflucan)
• fluoxetine (Prozac)
can increase the risk of side effects of Camzyos
strong or moderate CYP3A4 inducers*• carbamazepine (Tegretol, others)
• phenytoin (Dilantin)
• rifampin (Rifadin, Rimactane)
can make Camzyos less effective
strong or moderate CYP2C19 inducers*• apalutamide (Erleada)
• efavirenz
• enzalutamide (Xtandi)
can make Camzyos less effective
moderate CYP3A4 inhibitors• amiodarone (Pacerone)
• ciprofloxacin (Cipro)
• erythromycin (Erytab, others)
• danazol
can increase the risk of side effects of Camzyos
weak CYP2C19 inhibitors• nicardipine
omeprazole (Prilosec)
• oxcarbazepine (Trileptal)
can increase the risk of side effects of Camzyos
certain heart medications• beta-blockers, such as metoprolol (Lopressor)
• diltiazem (Cardizem CD, others)
• disopyramide (Norpace)
• ranolazine (Aspruzyo sprinkle)
verapamil (Verelan)
can increase the risk of side effects of Camzyos
combined birth control pills• ethinyl estradiol/
desogestrel (Cyclessa, others)
• ethinyl estradiol/
drospirenone (Yaz)
can make combined birth control pills less effective
drugs that are broken down by CYP3A4, CYP2C19, and CYP2C9 • glipizide (Glucotrol XL)
• midazolam (Nayzilam, Seizalam)
• repaglinide
can make drugs broken down by CYP3A4, CYP2C19, and CYP2C9 less effective

In some cases, factors or conditions could prevent your doctor from prescribing Camzyos due to the risk of harm. These are known as contraindications. The contraindications of Camzyos include:

Taking drugs that affect certain enzymes

Doctors typically will not prescribe Camzyos with drugs that affect certain enzymes in your body.

Specifically, doctors will not prescribe Camzyos with certain drugs that inhibit (reduce the action of) two enzymes: CYP3A4 and CYP2C19. These enzymes help clear Camzyos from your body. Taking Camzyos with drugs that inhibit these enzymes can make Camzyos build up in your body.

Taking Camzyos with drugs that are strong or moderate CYP2C19 inhibitors or strong CYP3A4 inhibitors can raise the risk of serious side effects from Camzyos, such as heart failure.* Doctors will likely not prescribe Camzyos with these drugs. Examples include:

  • certain seizure medications, such as:
    • cenobamate (Xcopri)
    • felbamate (Felbatol)
  • certain antifungals, such as:
    • fluconazole (Diflucan)
    • ketoconazole
    • itraconazole (Sporanox)
    • voriconazole (Vfend)
  • certain HIV drugs, such as:
    • cobicistat (Tybost)
    • nelfinavir (Viracept)
    • ritonavir (Norvir)
  • certain antidepressants, such as :
    • fluoxetine (Prozac)
    • fluvoxamine (Luvox)
    • nefazodone
  • certain drugs for excess stomach acid, such as:
    • cimetidine (Tagamet HB)
    • esomeprazole (Nexium)
  • the antibiotic clarithromycin
  • the blood thinner ticlopidine

Doctors will also likely not prescribe Camzyos with drugs that induce (increase the action of) CYP3A4 or CYP2C19. Taking Camzyos with drugs that are moderate or strong inducers of CYP3A4 or CYP2C19 can lower the level of Camzyos in your body. This can make Camzyos less effective at treating your heart condition.

Examples of these drugs include:

  • certain seizure medications, such as:
    • carbamazepine (Tegretol, others)
    • phenobarbital (Sezaby)
    • phenytoin (Dilantin)
    • primidone (Mysoline)
  • certain HIV drugs, such as:
    • efavirenz
    • etravirine (Intelence)
  • certain cancer drugs, such as:
    • apalutamide (Erleada)
    • dabrafenib (Tafinlar)
    • enzalutamide (Xtandi)
  • the antibiotic rifampin (Rifadin, Rimactane)

If you take any of these drugs, talk with your doctor about your treatment options. They may recommend switching to a different drug before starting Camzyos. Or they may recommend a treatment other than Camzyos for your heart condition.

* Camzyos has a boxed warning about the risk of heart failure. To learn more about this, see the boxed warning at the start of this article. For details about Camzyos’s side effects, see this article.

Having had an allergic reaction to Camzyos or any of its ingredients

If you have had an allergic reaction to Camzyos or any of its ingredients, your doctor will likely not prescribe Camzyos. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.

Note: Before you start treatment with Camzyos, it’s important to tell your doctor if these contraindications apply to you. They can determine whether to prescribe Camzyos.

There aren’t any known interactions between Camzyos and alcohol. However, your doctor may advise you to avoid or limit alcohol consumption during Camzyos treatment.

This is because drinking alcohol while taking the drug may worsen some of Camzyos’s side effects. For example, you may experience dizziness.

Drinking alcohol may also worsen dizziness caused by hypertrophic obstructive cardiomyopathy, which Camzyos is used to treat.

If you have questions about drinking alcohol while taking Camzyos, talk with your doctor.

Here’s a closer look at certain drug interactions of Camzyos.

Certain heart medications

Camzyos can interact with certain heart medications that weaken or slow your heartbeat. Drugs that have this effect may be used to treat angina, irregular heartbeats, and high blood pressure.

Interaction result: Taking Camzyos with drugs that weaken or slow your heartbeat can raise your risk of heart failure* with Camzyos.

Interaction explained: Camzyos relaxes your heart muscle and can cause heart failure in some people. Taking Camzyos with drugs that weaken or slow your heartbeat can weaken or slow your heartbeat too much. This can raise your risk of heart failure with Camzyos.

Examples of heart medications: Here are some heart medications that may interact with Camzyos:

  • beta-blockers, such as metoprolol (Lopressor)
  • diltiazem (Cardizem CD, others)
  • disopyramide (Norpace)
  • ranolazine (Aspruzyo sprinkle)
  • verapamil (Verelan)

Steps you or your doctor may take: Your doctor will likely not prescribe Camzyos if you take diltiazem or verapamil with a beta-blocker. They will also likely not prescribe Camzyos if you take disopyramide or ranolazine. If you take these drugs, talk with your doctor about your treatment options.

If your doctor prescribes Camzyos with diltiazem, verapamil, or a beta-blocker on its own, your doctor will likely monitor your heart more closely. Tell your doctor right away if you have symptoms of heart failure. These can include shortness of breath, swelling of your lower legs or feet, fatigue, or chest pain.

If you have questions about taking Camzyos with other heart medications, talk with your doctor or pharmacist.

* Camzyos has a boxed warning about the risk of heart failure. To learn more about this, see the boxed warning at the start of this article. For details about Camzyos’s side effects, see this article.

Combined birth control pills

Combined birth control pills contain estrogen and progestogen hormones. They are used to help prevent pregnancy.

Interaction result: Camzyos can make birth control pills less effective than usual at preventing pregnancy.

Interaction explained: Camzyos can increase the action of the enzyme CYP3A4. This enzyme helps break down the hormones in combined birth control pills. By increasing the action of CYP3A4, Camzyos can lower the levels of these hormones in your body. This can make them less effective at preventing pregnancy.

Examples of combined birth control pills: Here are some birth control pills that may interact with Camzyos:

  • ethinyl estradiol/desogestrel (Cyclessa, others)
  • ethinyl estradiol/drospirenone (Yaz, others)
  • ethinyl estradiol/ethynodiol diacetate (Kelnor, others)
  • ethinyl estradiol/levonorgestrel (Twirla, others)

Steps you or your doctor may take: If you are able to become pregnant, your doctor will likely recommend using an alternative form of birth control while you are taking Camzyos. (Note that Camzyos can cause fetal harm, so it’s important to use an effective form of birth control to avoid becoming pregnant while taking it.) Talk with your doctor about forms of birth control that may be a good option for you.

If you take Camzyos with a birth control pill, your doctor will likely recommend using a nonhormonal form of birth control, such as condoms, as well. Consider using extra birth control while taking Camzyos and for 4 months after stopping Camzyos.

If you have questions about taking Camzyos with birth control, talk with your doctor or pharmacist.

Omeprazole (Prilosec)

Camzyos can interact with omeprazole, which doctors prescribe to treat conditions caused by excess stomach acid. Examples include stomach ulcers and acid reflux. You can also buy omeprazole over-the-counter to treat heartburn.

Interaction result: Taking Camzyos with omeprazole can raise your risk of Camzyos side effects.

Interaction explained: Omeprazole inhibits (reduces the action of) an enzyme called CYP2C19. This enzyme helps clear Camzyos from your body. Omeprazole is a weak inhibitor of CYP2C19. But taking it with Camzyos can make Camzyos build up in your body. This can raise your risk of side effects of Camzyos.

Steps you or your doctor may take: If your doctor prescribes Camzyos with omeprazole, they will likely prescribe a dosage of Camzyos that’s lower than usual. Do not take a higher dose of either medication than your doctor recommends.

While taking Camzyos, you should not take over-the-counter omeprazole without first talking with your doctor.

If you have questions about taking Camzyos with omeprazole, talk with your doctor or pharmacist. For details about Camzyos’s side effects, see this article.

Camzyos may have other interactions, such as with supplements, foods, vaccines, or even lab tests. You’ll find details below. Keep in mind that the following information does not include all other possible interactions with Camzyos.

Camzyos interactions with supplements

Before you start treatment with Camzyos, tell your doctor and pharmacist which supplements, herbs, and vitamins you take. By sharing this information with them, you may help prevent possible interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Camzyos interactions with herbs

Doctors will typically recommend you avoid taking St. John’s wort with Camzyos. St. John’s wort is an herbal supplement that may be used to treat depression and other conditions.

St. John’s wort may speed up the activity of an enzyme in your body called CYP3A4. This enzyme helps break down Camzyos.

By speeding up this enzyme, St. John’s wort can cause Camzyos to break down more quickly. And this may lead to a low level of Camzyos in your system. If the level of Camzyos in your system is too low, the drug may not work to treat your heart condition.

Your doctor may be able to suggest a treatment option other than St. John’s wort.

Camzyos and vitamins

There are no specific reports of vitamins interacting with Camzyos. However, that doesn’t mean vitamin interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before taking any vitamin product with Camzyos.

Camzyos interactions with food

Grapefruit and grapefruit juice can interact with Camzyos. Specifically, grapefruit products can stop your body from breaking down Camzyos. This raises the level of Camzyos in your body, which increases your risk of side effects from Camzyos. Due to this risk, your doctor may recommend not consuming grapefruit and grapefruit juice while taking the drug.

For details about Camzyos’s side effects, see this article.

Camzyos and vaccines

There aren’t any known interactions between Camzyos and vaccines. Talk with your doctor or pharmacist to see whether you’re due for any vaccines.

Camzyos and lab tests

Camzyos isn’t known to interact with any lab tests. If you have concerns about this medication interacting with lab tests, talk with your doctor.

CAMZYOS INTERACTION WITH CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have not been specifically reported to interact with Camzyos.

However, cannabis and cannabis products are known to affect enzymes in your body that help break down Camzyos. So it’s possible that using cannabis while taking Camzyos could affect the level of Camzyos in your body. This could either raise your risk of Camzyos side effects or make Camzyos less effective at treating your heart condition.

As with any drug or supplement, talk with your doctor before using cannabis in combination with Camzyos. The impact of cannabis may also affect how well you stick to your Camzyos treatment plan.

Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.

Certain medical conditions and other factors may increase the risk of interactions with Camzyos. Before you take this drug, be sure to talk with your doctor about your health history. Camzyos may not be the right treatment option if you have certain medical conditions or other factors affecting your health.

Health conditions or factors that might interact with Camzyos include:

  • Heart failure: Camzyos has a boxed warning about the risk of heart failure in some people. This is a serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous. For details, see the boxed warning in this article.
  • Serious infection: A serious infection may increase the risk of heart failure. If you have a serious infection before or during treatment with Camzyos, let your doctor know. They can help decide if it’s safe to start or continue taking Camzyos.
  • Irregular heartbeat: An irregular heartbeat may increase the risk of heart failure. If you have a history of irregular heartbeat or develop an irregular heartbeat during treatment with Camzyos, let your doctor know. They can help decide if it’s safe to start or continue taking Camzyos.
  • Allergic reaction: If you’ve had an allergic reaction to Camzyos or any of its ingredients, your doctor will likely not prescribe Camzyos. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.
  • Breastfeeding: It’s not known whether it’s safe to use Camzyos while breastfeeding. There isn’t enough information to determine whether the drug passes into breast milk or what effects Camzyos may have on a child who is breastfed. If you’re breastfeeding or planning to, talk with your doctor before using Camzyos. They can talk with you about treatment options and ways to feed your child.
  • Pregnancy: There haven’t been enough clinical trials to determine whether Camzyos is safe to use while pregnant. Animal studies show that the drug may cause congenital anomalies (commonly known as birth defects) or pregnancy loss. However, it’s important to note that animal studies don’t always indicate what may happen in humans. If you’re pregnant or planning to become pregnant, tell your doctor before starting Camzyos. They can advise you on the right treatment plan for you.

You can take certain steps to help prevent interactions with Camzyos. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:

  • Let them know if you drink alcohol or use cannabis.
  • Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
  • Create a medication list, which your doctor and pharmacist can help you fill out.

It’s also important to read the Camzyos label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. And the paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions.

If Camzyos doesn’t come with paperwork, you can ask your pharmacist to print a copy. If you need help reading or understanding this information, ask your doctor or pharmacist.

You can also help prevent interactions with Camzyos by taking it exactly as your doctor prescribes.

Disclaimer: Medical News Today 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.