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Linezolid

Prescription

Oxazolidinone Antibiotic

Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

1 available

Interactions

3 documented

Formulations

Mechanism of action

Inhibits bacterial protein synthesis by binding to the 23S ribosomal RNA of the 50S subunit, preventing formation of the 70S initiation complex. Unique binding site — no cross-resistance with any other antibiotic class. Active against MRSA, VRE, and all gram-positives.

At a glance

Class

Oxazolidinone Antibiotic

Schedule

Prescription

Storage

Store at room temperature; IV bags protect from light; oral suspension use within 21 days

Dosing

🐕

Dog

Reserved for MDR gram-positive infections (MRSA, MRSP, VRE)

Dose

10 mg/kg

Route

PO, IV

Frequency

q12h

🐈

Cat

Same as dogs

Dose

10 mg/kg

Route

PO, IV

Frequency

q12h

Educational reference only

This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Other — 3

Strength

—

Strength

—

Strength

—

Storage

Store at room temperature; IV bags protect from light; oral suspension use within 21 days

Safety

Monitoring parameters

CBC weekly (thrombocytopenia)Clinical responseNeurological exam (neuropathy with >28 days use)Lactate if clinical concernLimit duration to ≤28 days if possible

Educational reference only

Interactions

Contraindicated — 1

Selegiline (L-Deprenyl)

contraindicated

Two MAO inhibitors (linezolid: reversible MAO-A; selegiline: irreversible MAO-B, with MAO-A activity at high doses): risk of hypertensive crisis and serotonin syndrome.

Management: NEVER combine. Allow 2-week washout of selegiline before linezolid.

Major — 2

Tramadol

major

Linezolid has weak reversible MAO-A inhibitory activity. Tramadol inhibits serotonin reuptake. Combined: serotonin syndrome risk.

Management: Avoid. If antibiotic needed with tramadol, use non-MAO-inhibiting antibiotic. If linezolid essential, use non-serotonergic opioid.

Fluoxetine

major

Linezolid (weak MAO-A inhibitor) + SSRI: serotonin syndrome risk (hyperthermia, seizures, rigidity).

Management: Avoid combination. If linezolid essential, taper SSRI before starting (fluoxetine requires 5-week washout due to long half-life metabolite).

Educational reference only

Brands

Other markets

Zyvox

FAQs

Frequently asked questions

›What is Linezolid?

Linezolid is a oxazolidinone antibiotic used in pets. Inhibits bacterial protein synthesis by binding to the 23S ribosomal RNA of the 50S subunit, preventing formation of the 70S initiation complex. Unique binding site — no cross-resistance with any other antibiotic class. Active against MRSA, VRE, and all gram-positives.

›What is Linezolid used for in pets?

Linezolid is used in veterinary medicine for: Reserved for MDR gram-positive infections (MRSA, MRSP, VRE); Same as dogs.

›What is the Linezolid dose for dogs?

For dogs, Linezolid is typically dosed as follows — Reserved for MDR gram-positive infections (MRSA, MRSP, VRE): 10 mg/kg PO/IV q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Linezolid dose for cats?

For cats, Linezolid is typically dosed as follows — Same as dogs: 10 mg/kg PO/IV q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›Does Linezolid need a prescription?

Yes. Linezolid is a prescription medication and should only be administered under veterinary supervision.

Educational reference only

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

Plumb's Veterinary Drug Handbook
Withrow & MacEwen's Small Animal Clinical Oncology
Merck Veterinary Manual
NRC Nutrient Requirements of Dogs and Cats
Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

ASPCA Animal Poison Control Center Guidelines
AAHA Diabetes Management Guidelines
ASPCA Poison Control Guidelines
RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

EPIC Study (J Vet Intern Med 2016)
JVIM FAT CAT Study

Regulatory & approvals — 1

CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

Washington State University VCPL MDR1 Database