Symtuza (darunavir/cobicistat/emtricitabine/tenofovir
alafenamide) is a brand-name oral tablet. Doctors prescribe it to treat HIV in certain situations. Symtuza has interactions with certain drugs and supplements, including blood thinners.

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

Keep reading to learn more about Symtuza’s interactions. For additional information about Symtuza, including details about its uses, see this article.

Before you start treatment with Symtuza, tell your doctor and pharmacist which prescription, over-the-counter, and other medications you take. Sharing this information with them may help prevent possible interactions. (To learn whether Symtuza interacts with supplements, herbs, or vitamins, see the “Symtuza and other interactions” section below.)

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

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

Drug class or drug nameDrug examplesInteraction result with Symtuza
corticosteroidsmethylprednisolone (Medrol)
prednisone (Rayos)
dexamethasone (Hemady)
can make Symtuza less effective or increase the risk of side effects of corticosteroids
beta-blockers• metoprolol (Lopressor, Toprol XL, others)
carvedilol (Coreg, Coreg CR)
bisoprolol
can increase the risk of side effects of beta-blockers
nonsteroidal anti-inflammatory drugs (NSAIDs)*ibuprofen (Advil, Motrin)
meloxicam (Mobic)
• celecoxib (Celebrex)
can increase the risk of side effects of NSAIDs and Symtuza†
blood thinners*• apixaban (Eliquis)
• rivaroxaban (Xarelto)
• dabigatran (Pradaxa)
can increase the risk of side effects of blood thinners and Symtuza†
certain antiviralsacyclovir (Sitavig)
valacyclovir (Valtrex)
• ganciclovir (Ganzyk-RTU)
can increase the risk of side effects of certain antivirals and Symtuza†
certain antibiotics• gentamicin
clarithromycin
erythromycin (Eryc, Ery-Tab, others)
can increase the risk of side effects of certain antibiotics and Symtuza†
certain cancer drugs• crizotinib (Xalkori)
• nilotinib (Tasigna)
• dasatinib (Sprycel)
can increase the risk of side effects of certain cancer drugs
certain antidepressantsamitriptyline
trazodone
nortriptyline (Pamelor)
can increase the risk of side effects of certain antidepressants
digoxin (Lanoxin)*can increase the risk of side effects of digoxin
salmeterol (Serevent)can increase the risk of side effects of salmeterol

* For details about this interaction, see the “Drug interactions in depth” section below.
† To learn more about the side effects of Symtuza, see the “Side effects” section in this article.

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

Taking certain drugs that Symtuza affects

Symtuza slows down the activity of an enzyme that helps break down certain medications in the body. (An enzyme is a type of protein.) By slowing this enzyme, Symtuza may prevent certain drugs from clearing your system as well as usual. This may lead to high levels of these medications in your body. In some cases, this can cause serious or life threatening effects.

Doctors typically won’t prescribe Symtuza in combination with such drugs. This is because high levels of these medications can increase the risk of their side effects.

Below are examples of some medications that Symtuza can affect. Keep in mind that this list doesn’t include all medications affected by Symtuza:

Before taking Symtuza, tell your doctor if you take any of these medications. They can decide whether to prescribe Symtuza.

* Sildenafil is available as the brand-name drugs Revatio and Viagra. Revatio is prescribed for pulmonary arterial hypertension (PAH), while Viagra is prescribed for erectile dysfunction (ED). When doctors prescribe Sildenafil for PAH, they typically won’t prescribe Symtuza with it. But when a doctor prescribes Sildenafil for ED, they may still prescribe Symtuza. However, they’ll typically prescribe a lower dosage of sildenafil to help reduce the risk of its side effects. To learn more, talk with your doctor or pharmacist.

Taking certain drugs that speed up the breakdown of Symtuza

Symtuza is broken down in your body by a specific enzyme. Certain medications may speed up the activity of this enzyme. In doing so, these drugs can cause Symtuza to break down more quickly. This may lead to low levels of Symtuza in your body.

Doctors typically won’t prescribe Symtuza in combination with such drugs. This is because low levels of Symtuza could make the drug less effective at treating HIV. This can also cause HIV to become resistant to Symtuza and similar medications. As a result, Symtuza and other HIV treatments won’t work as well.

Below are examples of some medications that speed up the breakdown of Symtuza. Keep in mind that this list doesn’t include all medications that may affect Symtuza:

  • rifampin (Rifadin, Rimactane)
  • certain antiseizure drugs such as phenobarbital (Sezaby) and carbamazepine (Carbatrol, Tegretol, others)

The herbal supplement St. John’s wort may also speed up the breakdown of Symtuza. Some people use this supplement to ease symptoms of depression and certain other conditions. To learn more, see the “Symtuza and other interactions” section below.

Before you start treatment with Symtuza, it’s important to tell your doctor if you take any of these medications. They’ll decide whether to prescribe Symtuza.

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

There are no known interactionsbetween Symtuza and alcohol. However, drinking alcohol while taking the drug may worsen some of Symtuza’s side effects. Examples include nausea, fatigue, and headache. To learn more about Symtuza’s side effects, see the “Side effects” section in this article.

If you have questions about drinking alcohol while taking Symtuza, talk with your doctor or pharmacist.

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

Nonsteroidal anti-inflammatory drugs

People typically take nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce inflammation, pain, and fever.

Interaction result. Taking Symtuza with NSAIDs can increase the risk of side effects from either drug. To learn about Symtuza’s side effects, see the “Side effects” section in this article.

Interaction explained. Your kidneys help remove Symtuza and NSAIDs from your body. Taking these medications together may slow down the activity of your kidneys. If your kidneys aren’t working well, Symtuza or NSAIDs may build up in your body. This could increase your risk of side effects from either drug.

Examples of NSAIDs. Here are some NSAIDs that may interact with Symtuza:

Steps you or your doctor may take. Before taking an NSAID with Symtuza, talk with your doctor or pharmacist. They can tell you about other options for treating inflammation, pain, or fever. For example, they may recommend acetaminophen (Tylenol) instead, which isn’t known to interact with Symtuza.

If you have other questions about Symtuza and NSAIDs, talk with your doctor or pharmacist.

Blood thinners

Doctors prescribe blood thinners to help prevent or treat blood clots in certain situations.

Interaction result. Taking Symtuza with blood thinners can increase the risk of side effects from either drug. To learn about Symtuza’s side effects, see the “Side effects” section in this article.

Interaction explained. In rare cases, Symtuza may increase the risk of bleeding. Blood thinners also increase this risk. Your risk of bleeding from taking both drugs together could be greater than from either drug alone.

Examples of blood thinners. Here are some blood thinners that may interact with Symtuza:

Steps you or your doctor may take. Before starting Symtuza treatment, tell your doctor if you’re taking a blood thinner. They can advise whether it’s safe to take these medications together. If your doctor says it’s safe, they may lower the dosage of your blood thinner. This may help reduce the risk of bleeding.

If you have other questions about Symtuza and blood thinners, talk with your doctor or pharmacist.

Digoxin

Doctors prescribe digoxin (Lanoxin) for heart failure and irregular heart rhythm.

Interaction result. Taking Symtuza with digoxin may increase the risk of side effects from digoxin.

Interaction explained. Symtuza may increase the level of digoxin in your body. A high level of the drug can raise your risk of side effects from digoxin.

Steps you or your doctor may take. Before taking Symtuza, tell your doctor if you’re taking digoxin. They can tell you whether it’s safe to take these medications together. If your doctor prescribes Symtuza with digoxin, they may lower your digoxin dosage. This may help reduce the risk of side effects from digoxin.

If you have other questions about Symtuza and digoxin, talk with your doctor or pharmacist.

Symtuzamay 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 Symtuza.

Symtuza interactions with supplements

Before you start treatment with Symtuza, 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.

Symtuza interactions with herbs

Doctors will typically recommend you avoid taking St. John’s wort with Symtuza. St. John’s wort is an herbal supplement that some people may use to treat depression and other conditions.

St. John’s wort may speed up the activity of an enzyme (a type of protein) in your body. This enzyme helps break down Symtuza. This means that St. John’s wort can cause Symtuza to break down more quickly. This may lead to a low level of Symtuza in your body.

If the level of Symtuza is too low, it may not work to treat HIV. This can also cause HIV to become resistant to Symtuza and similar medications. As a result, Symtuza and other HIV treatments won’t work as well.

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

Symtuza and vitamins

There are no specific reports of vitamins interacting with Symtuza. 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 Symtuza.

Symtuza interactions with food

Grapefruit and grapefruit juice can interact with Symtuza. Specifically, these products can slow the breakdown of Symtuza in your body. This raises the level of Symtuza in your body, which increases your risk of side effects from Symtuza. Due to this risk, your doctor may recommend avoiding grapefruit and grapefruit juice while taking the drug.

To learn about side effects of Symtuza, see the “Side effects” section in this article.

Symtuza and vaccines

There are not any known interactions between Symtuza and vaccines. Be sure to talk with your doctor or pharmacist to see whether you’re due for any vaccines.

Symtuza and lab tests

Symtuza is not known to interact with any lab tests. If you have concerns about this medication interacting with lab tests, talk with your doctor.

SYMTUZA INTERACTION WITH CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have been specifically reported to interact with Symtuza.

Taking Symtuza with cannabis products can raise the level of Symtuza in your body, increasing your risk of side effects from the drug.

Before you start treatment with Symtuza, tell your doctor and pharmacist if you use cannabis. By sharing this information with them, you may help prevent possible interactions.

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

Certain medical conditions and other factors may increase the risk of interactions with Symtuza. Before you take this drug, be sure to talk with your doctor about your health history. Symtuza 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 Symtuza include:

Bleeding problems. If you have a bleeding problem such as hemophilia, talk with your doctor before taking Symtuza. The drug could further increase your risk of bleeding. Your doctor can tell you whether Symtuza is a safe treatment option.

Diabetes. Before starting Symtuza treatment, tell your doctor if you have diabetes. The drug may cause high blood sugar levels. This could make it harder to manage diabetes. Your doctor can advise whether Symtuza is the right treatment for you.

Severe liver or kidney problems. Before taking Symtuza, tell your doctor if you have a severe liver or kidney problem. Examples include liver failure and kidney failure. These conditions may cause Symtuza to build up in your system, increasing the risk of the drug’s side effects. If you have a severe liver or kidney problem, your doctor may prescribe a different HIV treatment instead. (Symtuza is prescribed to treat HIV in certain situations.)

Allergic reaction. If you’ve had an allergic reaction to Symtuza, any of its ingredients, or a sulfa drug, your doctor will likely not prescribe Symtuza. 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 recommended that you avoid breastfeeding while taking Symtuza. The drug passes into breast milk and may cause side effects in an infant who is breastfeeding. If you’re breastfeeding or planning to, talk with your doctor before taking Symtuza. They can talk with you about treatment options and ways to feed your child.

Pregnancy. Symtuza is not recommended for HIV treatment during pregnancy. This is because the level of Symtuza during pregnancy may not be high enough to treat HIV. If you’re pregnant or planning to become pregnant, tell your doctor before starting Symtuza. They can advise you on the right treatment plan for you.

If you take Symtuza while pregnant, consider enrolling in the drug’s pregnancy registry. This registry keeps track of pregnancy-related issues when people take Symtuza during pregnancy. To learn more, talk with your doctor. You can also call 800-258-4263 or visit the registry website.

Risk of worsening hepatitis B. Symtuza has a boxed warning about the risk of worsening hepatitis B. A boxed warning is the most 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 “Boxed warning” at the top of this article.

You can take certain steps to help prevent interactions with Symtuza. 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 Symtuza 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 Symtuza does not 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 Symtuza by taking it exactly as your doctor prescribes.

Besides learning about interactions, you may want to find out more about Symtuza. These resources might help:

  • Overview of Symtuza. For a general overview of Symtuza, you can see this article.
  • Dosage specifics. To learn about the dosage of Symtuza, see this article.
  • Cost. If you’d like to learn about Symtuza and cost, see this article.
  • Facts about your condition. To learn more about your condition, see our HIV and AIDS hub.

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.