4 Linezolid Interactions You Should Know About

Linezolid (Zyvox) is an antibiotic that treats many types of bacterial infections. Examples include pneumonia and skin infections. It can also treat some infections that are resistant to other antibiotics. It’s available as a tablet, oral liquid, and intravenous (IV) infusion.

Linezolid is usually only used for 10 to 14 days. But it can still have interactions with other medications, supplements, and foods. Here, we’ll cover four of the most important linezolid interactions to consider. Keep in mind, this isn’t a complete list. So give your healthcare provider and pharmacist a list of all the medications and supplements you take. And talk to them about the foods you eat on a day-to-day basis. This will help them check for linezolid interactions.

1. Monoamine oxidase inhibitors

Monoamine oxidase inhibitors (MAOIs) are medications that treat depression and Parkinson’s disease. Examples of MAOIs include isocarboxazid (Marplan), phenelzine (Nardil), and selegiline (Emsam). MAOIs aren’t commonly used because they have many drug and food interactions. This includes a possible interaction with linezolid.

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MAOIs and linezolid block an enzyme (protein) in the body called monoamine oxidase (MAO). MAO breaks down certain chemical messengers that our cells use to communicate. When MAO is blocked, these chemical messengers increase in the body. This includes dopamine, norepinephrine, and serotonin. It also includes tyramine, a naturally occurring chemical in the body that’s also found in some foods.

Combining MAOIs with linezolid can cause an excessive amount of these chemicals in the body. This can lead to MAOI toxicity. Symptoms range from mild (fast heartbeat, agitation, or sweating) to severe (muscle rigidity, seizures, and heat stroke). Severe MAOI toxicity can be life threatening.

In most cases, MAOIs and linezolid shouldn’t be used at the same time. In fact, they shouldn’t be used within 2 weeks of each other. If you have a life-threatening infection that requires linezolid, your healthcare provider may make an exception. But this is rare.

2. Medications that increase serotonin

Serotonin is a chemical that helps regulate mood and other bodily functions. Many medications work by increasing serotonin levels. This helps treat conditions like depression, anxiety, and migraines. But if you take multiple medications that increase serotonin, serotonin levels can rise too high. This may lead to a condition called serotonin syndrome.

Examples of medications that increase serotonin levels include:

• MAOIs

• Selective serotonin reuptake inhibitors (SSRIs), like citalopram (Celexa) and sertraline (Zoloft)

• Serotonin and norepinephrine reuptake inhibitors (SNRIs), like venlafaxine and duloxetine (Cymbalta)

• Some atypical antidepressants, like mirtazapine (Remeron) and bupropion (Wellbutrin SR, Wellbutrin XL)

• Tricyclic antidepressants, like amitriptyline

• Triptans, like sumatriptan (Imitrex)

• Some anti-nausea medications, like ondansetron (Zofran)

• Some opioid pain medications, like tramadol (Conzip) 

• St. John's wort

Most cases of serotonin syndrome are mild. You might feel shaky or sweaty, or have a racing heartbeat. But in rare cases, serotonin syndrome can be serious. Get emergency care if you have severe symptoms, such as a high fever, muscle stiffness, or confusion.

Your healthcare provider may recommend a different antibiotic if you take any of these medications. But if you have a serious infection that requires linezolid, it may be necessary to take it. You might need to temporarily stop your other medications that increase serotonin. But don’t make any changes without instructions from your provider.

3. Adrenergic medications

Adrenergic medications attach (bind) to specific sites throughout the body called adrenergic receptors. Some adrenergic medications increase the same chemicals as linezolid (like norepinephrine and dopamine). High levels of these chemicals can increase your blood pressure and heart rate.

Many medications are considered adrenergic medications. A few are IV medications used only in hospital settings. But some adrenergic medications are available over the counter (OTC). This includes pseudoephedrine (Sudafed) and phenylephrine (Sudafed PE). These medications are also part of many cold and flu combination products. For example, phenylephrine is one ingredient in Dayquil Cold and Flu.

Check with your provider or pharmacist before taking any OTC product with linezolid. They can help you make sure the OTC product is safe. Many prescription medications also have adrenergic properties. This includes stimulant medications like Adderall (mixed amphetamine salts) and phentermine (Adipex-P).

Linezolid may be safe to take with some adrenergic medications. Your provider may just monitor your blood pressure or heart rate more closely. But in other cases, they may recommend avoiding adrenergic medications while taking linezolid.

4. Tyramine-containing foods

Tyramine is an amino acid (a building block of proteins). It’s found naturally in the body and in some foods.

Linezolid prevents your body from breaking down tyramine. But too much tyramine can cause high blood pressure. In severe cases, it can lead to a hypertensive crisis (when blood pressure is greater than 180/120 mm Hg). Symptoms may include shortness of breath, severe headache, and anxiety. If you experience this, you should seek emergency care.

To prevent a hypertensive crisis, avoid eating or drinking too many products with tyramine while taking linezolid. Foods and drinks high in tyramine include:

• Aged cheeses

• Aged, cured, pickled, or smoked meats like sausage, salami, and pepperoni

• Fermented soy products like miso, tofu, or soy sauce

• Fermented produce like kimchi, sauerkraut, and pickles

• Fermented bread like sourdough

• Beer on tap

Some supplements also contain tyramine. So check with your provider or pharmacist before taking any supplements with linezolid.

When should I contact my healthcare provider about a Linezolid interaction?

If you notice mild signs of a linezolid interaction, let your healthcare provider know. This includes slightly high blood pressure, sweating, or a faster heartbeat. They can evaluate your symptoms and let you know what to do next.

If your symptoms are severe, seek emergency care. This includes a high fever, very high blood pressure (180/120 mmHg or more), or confusion.

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Written by:

Daphne Berryhill, RPh

Daphne Berryhill, RPh, has two decades of experience as a clinical pharmacist. She spent most of her career in the Chicago area practicing in-home infusion.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

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