Brian asked
I had a general question about a medication. I've been prescribed Linezolid (Zyvox) by my doctor and have read about a special diet needed to accompany this medication (low tyramine diet) to keep blood pressure from dangerous rates. I'm a bit anxious about taking this medication and just wondered what your experience may have been with Zyvox. Is it commonly used and typically considered safe?
Answer
Zyvox (linezolid) is not a commonly used antibiotic, but not necessarily because the drug is unsafe. In fact, Zyvox is an extremely effective antibiotic that is used to cure resistant microbial infections including:
- Resistant Pneumonia
- Vancomycin-resistant enterococcal (VRE) infections
- MRSE (Methicillin-resistant Staphylococcus aureus)
There are a few reasons Zyvox isn't widely used:
- Resistance
- Cost
- Limited Use
- Interactions
Resistance
It is important to sparingly use new, effective antibiotics to prevent resistant organisms. Unfortunately, there have been confirmed reports that Zyvox resistant organisms are occurring at various health care locations. Inappropriate and overuse of the drug has led to an increase in resistant organisms and generally, alternative treatments are to be considered prior to using Zyvox, especially in an outpatient setting.
Cost
Zyvox is expensive, especially for patients paying at a retail pharmacy. Single courses of the antibiotic can cost thousands of dollars and insurance companies typically require patients to try alternative therapies first.
Adverse Reactions
Along the same lines of sparing use due to resistance, Zyvox is very effective but only for certain infections. It isn't considered a broad spectrum, "one size fits all" antibiotic. It is generally only effective for certain susceptible bacteria that are gram positive. There have been certain adverse reactions linked to the drugs use for infections caused by gram negative organisms and it should be avoided in those situations.
Zyvox Food Interactions
Zyvox, while easily dosed, does have restrictions when it comes to food intake. In addition to its antimicrobial effects, Zyvox is a MAO (Monoamine Oxidase) inhibitor.
MAO is a complex enzyme system in the body and inhibition of MAO can result in an increased concentration of neurotransmitters (e.g. norepinephrine, serotonin). In fact, MAO inhibitor medications are used for treat depressive disorders.
Unfortunately, the metabolism of tyramine, an amino acid derivative common in many foods, is highly dependent on MAO. Inhibition of MAO can result in high levels of tyramine, potentially causing a hypertensive crisis (i.e dangerously high blood pressure).
Tyramine rich foods are recommended to be avoided if you are taking a medication that inhibits MAO, as Zyvox does. Common foods high in tyramine include:
- Cheeses
- Fermented foods
- Pickled foods
- Smoked foods
- Aged meats
- Certain beans
- Certain nuts
- Soy foods
Be sure to follow a strict diet of low tyramine foods while taking Zyvox to prevent any sort of reaction.
