Oxazolidinone Antibiotic Pregnancy: Limited data in pregnant women; animal studies have shown reproductive toxicity and a potential risk for humans exists — linezolid should not be used during pregnancy unless clearly necessary, i.e. only if the potential benefit outweighs the theoretical risk. Breast-feeding should be discontinued prior to and throughout administration.

Linezolid (MRSA Osteomyelitis)

Brand names: Zyvox

Linezolid is an oxazolidinone antibiotic used in orthopaedics for serious Gram-positive bone and joint infection, including MRSA osteomyelitis and prosthetic-joint infection, and is valued for its good oral bioavailability and bone penetration.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 600 mg twice daily

Route: Intravenous infusion over a period of 30 to 120 minutes (fetched SPC is Linezolid 2 mg/ml solution for infusion). Patients started on the parenteral formulation may be switched to either oral presentation when clinically indicated, with no dose adjustment (oral bioavailability approximately 100%).

Frequency: Twice daily

Max: Maximum treatment duration 28 days — safety and effectiveness beyond 28 days have not been established

SPC §4.2 dose table for the solution for infusion: nosocomial pneumonia 600 mg twice daily for 10–14 consecutive days; community-acquired pneumonia 600 mg twice daily; complicated skin and soft tissue infections 600 mg twice daily. BONE AND JOINT INFECTION / OSTEOMYELITIS IS NOT A LICENSED INDICATION IN THIS SPC and no dose or duration is stated for it — the 600 mg twice daily figure above is the SPC dose common to all its licensed indications; confirm the osteomyelitis regimen and duration against local/specialist guidance, noting the 28-day maximum duration and the myelosuppression risk with courses beyond 10–14 days. No increase in dose or duration is required for infections associated with concurrent bacteraemia. Duration depends on pathogen, site and severity of infection and clinical response. Elderly: no dose adjustment required. Hepatic impairment: no dose adjustment required, but limited clinical data — use only when the anticipated benefit outweighs the theoretical risk. PAEDIATRIC: safety and efficacy in children under 18 years has not been established and NO POSOLOGY RECOMMENDATION CAN BE MADE (§4.2) — direct prescribers to a children's formulary. §4.5 (interactions) was not part of the fetched bundle — the interaction entries below are taken verbatim from §4.3. §4.4 and §4.8 were truncated at the source-fetch limit.

Dose adjustments

Renal

No dose adjustment is required at any degree of renal impairment, including severe impairment (CrCl less than 30 ml/min). However, because of the unknown clinical significance of up to 10-fold higher exposure to the two primary metabolites, use with special caution in severe renal insufficiency and only when the anticipated benefit outweighs the theoretical risk. Approximately 30% of a linezolid dose is removed during 3 hours of haemodialysis, so linezolid should be given after dialysis. Thrombocytopenia may occur more commonly in severe renal insufficiency, with or without dialysis. There is no experience in CAPD or renal replacement other than haemodialysis.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to linezolid or to any of the excipients
Patients taking any medicinal product which inhibits monoamine oxidases A or B (e.g. phenelzine, isocarboxazid, selegiline, moclobemide), or within two weeks of taking any such medicinal product
Unless facilities for close observation and blood pressure monitoring are available: uncontrolled hypertension, phaeochromocytoma, carcinoid, thyrotoxicosis, bipolar depression, schizoaffective disorder, acute confusional states
Unless facilities for close observation and blood pressure monitoring are available: patients taking serotonin re-uptake inhibitors, tricyclic antidepressants, serotonin 5-HT1 receptor agonists (triptans), directly and indirectly acting sympathomimetics (including adrenergic bronchodilators, pseudoephedrine, phenylpropanolamine), vasopressive agents (e.g. epinephrine, norepinephrine), dopaminergic agents (e.g. dopamine, dobutamine), pethidine or buspirone
Breast-feeding should be discontinued prior to and throughout administration

Side effects

Diarrhoea (8.4%), nausea (6.3%) and vomiting (4.0%)
Headache (6.5%), taste perversion (metallic taste), dizziness
Candidiasis (oral and vaginal) and other fungal infections
Myelosuppression — anaemia, leucopenia, neutropenia, thrombocytopenia, pancytopenia and sideroblastic anaemia; monitor full blood counts weekly (higher risk with therapy beyond 10–14 days, in severe renal insufficiency and in the elderly)
Optic neuropathy/optic neuritis, blurred vision, visual field defect and loss of vision; peripheral neuropathy (mainly with prolonged use)
Serotonin syndrome, lactic acidosis, convulsions, hyponatraemia and antibiotic-associated (including pseudomembranous) colitis

Interactions

Monoamine oxidase A or B inhibitors (e.g. phenelzine, isocarboxazid, selegiline, moclobemide) — contraindicated, including within two weeks of stopping them
Serotonergic agents: serotonin re-uptake inhibitors, tricyclic antidepressants, 5-HT1 agonists (triptans), pethidine, buspirone — contraindicated unless close observation and blood pressure monitoring are available (serotonin syndrome is a listed adverse reaction)
Sympathomimetics (direct and indirect, including adrenergic bronchodilators, pseudoephedrine, phenylpropanolamine) and vasopressors (e.g. epinephrine, norepinephrine) — contraindicated unless close observation and blood pressure monitoring are available
Dopaminergic agents (e.g. dopamine, dobutamine) — contraindicated unless close observation and blood pressure monitoring are available
Full §4.5 interaction section was not retrieved in this bundle — check the SPC directly before relying on this list

Clinical monograph

How it works

It inhibits bacterial protein synthesis by binding the 23S ribosomal RNA of the 50S subunit, preventing formation of the initiation complex; it is active against MRSA and other resistant Gram-positive organisms.

Prescribing in practice

Prolonged courses (as needed for osteomyelitis) carry a significant risk of myelosuppression and of peripheral and optic neuropathy, so duration must be limited and reviewed and full blood counts monitored.
It is a reversible monoamine oxidase inhibitor — avoid combining with serotonergic drugs (SSRIs, SNRIs, triptans) and other MAOIs, and counsel on tyramine-rich foods, because of serotonin syndrome and hypertensive risk.
Caution in uncontrolled hypertension and phaeochromocytoma; review concomitant adrenergic and serotonergic agents before starting.

Monitoring

Monitor full blood count weekly, and assess visual function and for neuropathic symptoms on prolonged courses.

Counselling the patient

Report any new vision changes, numbness or tingling in the hands or feet.
Avoid certain antidepressants and aged or fermented foods unless cleared by your team.
Blood tests are needed regularly while you take this antibiotic.

Evidence & guidelines

MHRA has warned of severe optic and peripheral neuropathy and blood disorders with linezolid, particularly when used beyond the recommended duration.

Reference: IDSA MRSA Guidelines 2011; NICE Antimicrobial Prescribing Guidelines; MHRA Linezolid Safety Update; SPC Zyvox; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Linezolid · Oxazolidinone antibiotic

Pathways