An oxazolidinone antibiotic
Linezolid
An antibiotic used for certain serious bacterial infections, including some resistant ones, usually under specialist guidance.
What is Linezolid?
Linezolid is an oxazolidinone antibiotic used for certain serious bacterial infections, including some caused by resistant bacteria such as MRSA, usually under specialist supervision. It is a weak monoamine oxidase inhibitor (MAOI), so tyramine-rich foods and some serotonergic medicines must be avoided to prevent dangerous reactions. With longer use it can suppress blood counts and, rarely, affect the eyes or nerves, so monitoring is important.
Education and reference only. This is a plain-language guide to Linezolid — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Linezolid is an oxazolidinone antibiotic used in the UK for certain serious infections, including some pneumonias and skin and soft-tissue infections, particularly when bacteria are resistant to other antibiotics (such as MRSA). It is generally used under specialist guidance and reserved for situations where it is genuinely needed, to help preserve its effectiveness. It can be given as tablets or an injection.
How it works
Linezolid works by blocking an early step in the way bacteria build the proteins they need to grow, which stops them multiplying and helps the infection clear. It is active against several difficult, resistant bacteria, which is why it is kept for specific situations. Separately, it has a mild action as a monoamine oxidase inhibitor — affecting the breakdown of certain brain chemicals — which is the reason for its food and medicine cautions. It treats bacterial infections only and has no effect on viruses.
Company & origin
Originated / developed by: A reserve antibiotic for resistant infections.
An antibiotic used in the UK for certain serious infections, including some caused by bacteria resistant to other antibiotics.
Practical use
How to take Linezolid
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it exactly as prescribed and complete the full course, even if you feel better.
- Avoid large amounts of tyramine-rich foods, such as mature cheese, cured or fermented meats, soy sauce and draught beer.
- Tell your team about all your medicines, especially antidepressants, as these can cause dangerous interactions.
- Report any new vision changes, numbness, tingling or unusual bruising or bleeding promptly.
- If you miss a dose, take it as soon as you remember unless it is nearly time for the next; do not double up.
Weighing it up
Advantages & disadvantages of Linezolid
Advantages
- Effective against some serious, resistant bacteria, including MRSA.
- Available as both tablets and an injection, with good absorption from tablets.
- A valuable reserve option when other antibiotics cannot be used.
Disadvantages
- Acts as a weak MAOI, so it needs food and medicine restrictions.
- Can suppress blood counts and, rarely, affect the eyes or nerves with longer use.
- Usually reserved for specialist use and not suitable for routine infections.
Practical use
Good to know
Because linezolid is a weak monoamine oxidase inhibitor (MAOI), you should avoid large amounts of tyramine-rich foods — such as mature cheeses, cured or fermented meats, soy sauce and draught beer — as these can cause a sharp rise in blood pressure. It can also interact with medicines that raise serotonin (including some antidepressants), risking a dangerous reaction called serotonin syndrome, so your full medicine list must be reviewed. With courses longer than a couple of weeks it can lower blood counts and, rarely, cause nerve or eye problems, so blood tests are checked and you should report any change in vision, numbness or tingling. Tell your team about any other medicines, and complete the course as prescribed.
Who should not take it / use with caution
- People who have had a serious allergic reaction to linezolid should not take it.
- Used with great caution, or avoided, in people taking certain antidepressants or other serotonergic medicines, and those with uncontrolled high blood pressure.
- Used carefully in people with low blood counts, and in pregnancy or breastfeeding only when clearly needed.
Monitoring
- Full blood count, especially when treatment lasts longer than about two weeks.
- Vision and any symptoms of nerve problems with longer use.
- Blood pressure and response of the infection.
Side effects
- Nausea, diarrhoea, headache and changes in taste are among the more common effects.
- Lowered blood counts (causing tiredness, bruising or infections), particularly with longer courses.
- Rarely, nerve or eye problems (numbness, tingling or vision changes) or serotonin syndrome when combined with certain medicines.
Key interactions
- Medicines that raise serotonin — including many antidepressants — can cause serotonin syndrome, a serious reaction.
- Some decongestants and medicines that raise blood pressure can interact because of its MAOI action.
- Always tell every prescriber and pharmacist that you are taking linezolid before starting any new medicine.
Available as: Tablets and an oral suspension; also an injection used in hospital.
Answers
Linezolid: frequently asked questions
What is linezolid used for?
It treats certain serious bacterial infections, including some caused by resistant bacteria such as MRSA, often when other antibiotics cannot be used. It is usually prescribed under specialist guidance and does not work against viruses.
Why do I need to avoid certain foods on linezolid?
Linezolid is a weak monoamine oxidase inhibitor, so large amounts of tyramine-rich foods — like mature cheese, cured meats, soy sauce and draught beer — can cause a sharp rise in blood pressure. Eating normal amounts of fresh food is generally fine; your team can give specific advice.
Can I take my antidepressant with linezolid?
Not always — some antidepressants and other medicines that raise serotonin can combine with linezolid to cause serotonin syndrome, a serious reaction. Tell your team about every medicine you take so they can check it is safe or make adjustments.
Why are blood tests needed during treatment?
With longer courses linezolid can lower blood counts, causing tiredness, bruising or a higher infection risk, so blood tests keep a check on this. Report any unusual bruising, bleeding or persistent tiredness to your team.
Should I report changes in my eyesight?
Yes — rarely linezolid can affect the eyes or nerves, especially with longer use, so report any change in vision, colour vision, numbness or tingling promptly. Early reporting allows your team to review treatment quickly.
The wider class
About Oxazolidinone antibiotics
Linezolid belongs to the oxazolidinone antibiotics class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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