What to avoid with linezolid?

October 6, 2025 •

3 min read

Linezolid is a powerful antibiotic often reserved for treating serious bacterial infections, including those resistant to other drugs like MRSA [1.7.6]. A key question for patient safety is what to avoid with linezolid? because it also acts as a reversible, non-selective monoamine oxidase inhibitor (MAOI), leading to significant interactions [1.7.1, 1.2.2].

Quick Summary

Taking linezolid requires avoiding specific medications, especially serotonergic drugs, to prevent serotonin syndrome. Patients must also avoid foods high in tyramine to prevent a dangerous increase in blood pressure.

Key Points

Drug Interactions: Avoid serotonergic drugs like SSRIs and SNRIs to prevent potentially fatal serotonin syndrome [1.3.5].
Food Interactions: Do not consume foods high in tyramine, such as aged cheeses and cured meats, to avoid a dangerous spike in blood pressure [1.2.2].
MAOI Properties: Linezolid is a reversible MAOI, which is the root cause of its major food and drug interactions [1.7.1].
OTC Medications: Avoid over-the-counter decongestants containing pseudoephedrine or phenylephrine [1.2.3].
Medical Conditions: Use with caution or avoid completely if you have uncontrolled hypertension, certain tumors, or pre-existing blood disorders [1.5.2].
Alcohol: Avoid alcoholic beverages, especially tap beer and red wine, due to high tyramine content [1.2.1].
Communication is Key: Always provide your doctor with a complete list of your medications, supplements, and health conditions before starting linezolid [1.2.3].

Linezolid is an essential antibiotic from the oxazolidinone class, used to combat complex bacterial infections such as those caused by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) [1.7.6, 1.7.7]. Its unique mechanism involves inhibiting the initiation of bacterial protein synthesis, making it effective where other antibiotics may fail [1.7.3, 1.7.4]. However, linezolid also functions as a weak, reversible monoamine oxidase inhibitor (MAOI) [1.7.1, 1.7.7]. This dual action is the primary reason for its significant interactions with certain drugs, foods, and medical conditions.

Critical Drug Interactions to Avoid

Due to its MAOI properties, linezolid can dangerously increase levels of certain neurotransmitters like serotonin, norepinephrine, and dopamine when combined with other medications [1.2.2]. It is crucial to inform your healthcare provider of all medications you take, including over-the-counter (OTC) drugs and supplements [1.2.3].

Serotonergic Drugs and Serotonin Syndrome

The most critical interaction is with serotonergic drugs, which can lead to a potentially fatal condition called serotonin syndrome [1.3.5]. This syndrome occurs from an excess of serotonin in the brain [1.6.1]. Symptoms range from mild (agitation, sweating, rapid heart rate, tremors) to severe (high fever, seizures, muscle rigidity, and loss of consciousness) [1.6.3].

Medications to avoid or use with extreme caution include:

SSRIs (Selective Serotonin Reuptake Inhibitors): citalopram (Celexa), sertraline (Zoloft), fluoxetine (Prozac), escitalopram (Lexapro) [1.3.4, 1.2.2].
SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors): venlafaxine (Effexor), duloxetine (Cymbalta) [1.3.4, 1.2.2].
Tricyclic Antidepressants (TCAs): amitriptyline, imipramine [1.2.2, 1.4.2].
Other MAOIs: phenelzine (Nardil), isocarboxazid (Marplan). Linezolid should not be taken within two weeks of using another MAOI [1.5.2].
Opioid Pain Medications: tramadol, meperidine, fentanyl [1.2.2, 1.6.5].
Triptans: sumatriptan (Imitrex), rizatriptan [1.2.2].
Other medications: buspirone, bupropion, St. John's wort [1.2.2, 1.3.1].

Adrenergic and Dopaminergic Agents

Combining linezolid with drugs that increase norepinephrine and dopamine can cause a significant and dangerous increase in blood pressure (hypertensive crisis) [1.2.2].

Decongestants: Over-the-counter cold medicines containing pseudoephedrine or phenylephrine must be avoided [1.2.3].
Stimulants: Medications for ADHD like amphetamine (Adderall) and methylphenidate [1.3.1, 1.2.2].
Pressor Agents: Vasopressive and dopaminergic drugs like epinephrine, norepinephrine, and dopamine [1.5.2].

Dietary Restrictions: The Tyramine Effect

Linezolid's MAOI activity prevents the breakdown of tyramine, an amino acid found in certain foods [1.2.2]. Consuming high-tyramine foods can lead to a rapid, dangerous spike in blood pressure [1.4.6].

Foods High in Tyramine to Avoid

Aged Cheeses: Cheddar, blue cheese, Swiss, Parmesan, brie, feta [1.4.2, 1.2.4].
Cured, Smoked, or Pickled Meats/Fish: Salami, pepperoni, sausage, pickled herring, smoked salmon [1.2.4, 1.4.1].
Fermented Products: Sauerkraut, kimchi, tofu, miso, soy sauce [1.2.2, 1.4.4].
Alcoholic Beverages: Tap beer (draft beer) and some red wines are particularly high in tyramine [1.2.1, 1.2.4].
Other Foods: Overripe fruits (like avocados and bananas), sourdough bread, fava beans, and yeast extracts (like Marmite) [1.2.6, 1.4.2].


Interaction Type	High-Risk Examples	Potential Consequence	Severity
Serotonergic Drugs	SSRIs (sertraline), SNRIs (duloxetine), Tramadol	Serotonin Syndrome [1.3.5]	Major
Adrenergic Drugs	Pseudoephedrine, Phenylephrine, Amphetamine	Hypertensive Crisis [1.3.6]	Major
Tyramine-Rich Foods	Aged cheese, Cured meats, Tap beer	Hypertensive Crisis [1.2.2]	Major
Other MAOIs	Phenelzine, Selegiline	MAOI Toxicity [1.2.2]	Major

Pre-existing Conditions and Precautions

Certain health conditions require caution or contraindicate the use of linezolid. Always inform your doctor about your full medical history [1.5.1].

Uncontrolled High Blood Pressure: Linezolid can worsen hypertension [1.5.2].
Thyroid Disease: Patients with thyrotoxicosis should not take linezolid unless closely monitored [1.5.2].
Tumors: Pheochromocytoma or carcinoid syndrome are contraindications [1.5.2].
Blood Disorders: Patients with pre-existing myelosuppression (low blood cell counts) need weekly blood monitoring [1.5.2].
Diabetes: Cases of symptomatic hypoglycemia have been reported in diabetic patients taking insulin or oral hypoglycemic agents [1.5.2].

Conclusion

Linezolid is a critical tool against resistant bacteria, but its safety hinges on strict adherence to avoiding specific drugs and foods. Its properties as a monoamine oxidase inhibitor necessitate careful management to prevent severe reactions like serotonin syndrome and hypertensive crisis. The most important step for any patient is to maintain open communication with their healthcare provider, providing a complete list of all medications and supplements being taken and discussing dietary habits before starting treatment [1.2.2, 1.2.3].

For more detailed information, consult the official FDA guidance on linezolid. https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-serious-cns-reactions-possible-when-linezolid-zyvox-given-patients [1.6.1]

Frequently Asked Questions

You should limit your intake of caffeine-containing products like coffee, tea, and chocolate. Linezolid can potentiate caffeine's effects, possibly leading to increased blood pressure and restlessness [1.2.1].

Eating aged cheeses (like cheddar, blue cheese, or parmesan) is dangerous because they are high in tyramine. This can cause a rapid and severe increase in blood pressure, known as a hypertensive crisis [1.2.4, 1.4.6].

Serotonin syndrome is a potentially life-threatening condition caused by excessive serotonin levels in the brain. Symptoms include confusion, agitation, muscle twitching, sweating, and rapid heartbeat. It can be triggered by taking linezolid with serotonergic drugs like antidepressants [1.6.1, 1.6.3].

You must not take linezolid if you have taken a monoamine oxidase inhibitor (MAOI) within the last two weeks [1.5.2]. For SSRIs, you should consult your healthcare provider, as some may need to be stopped for a period before starting linezolid to avoid serotonin syndrome [1.6.1].

While major interactions with acetaminophen (Tylenol) are not listed as a primary concern, you should always give a complete list of all medicines you are taking, including OTC drugs, to your doctor or pharmacist before starting linezolid [1.4.2].

Common side effects of linezolid include diarrhea, headache, and nausea [1.5.5]. However, more serious side effects can occur, so it's important to report any unusual symptoms to your doctor.

Many over-the-counter cold medicines contain decongestants like pseudoephedrine or phenylephrine. These are adrenergic agents that, when combined with linezolid, can cause a dangerous increase in blood pressure [1.2.3, 1.3.6].