Drug reference

Linezolid

Oxazolidinone · Antibiotic

Also known as Zyvox, Linospan, Lizolid, Linez, LNZ

START

Confirm MRSA/VRE infection or approved indication. Obtain baseline CBC, LFTs. Screen all medications for serotonergic agents and sympathomimetics. Counsel on tyramine-restricted diet (aged cheese, cured meats, fermented foods, wine).

TYPICAL MAX

600 mg q12h. Limit to ≤28 days unless no alternatives and close monitoring (myelosuppression, neuropathy risk).

STOP IF

Platelet count <100,000 (or 50% drop from baseline), signs of serotonin syndrome, optic/peripheral neuropathy symptoms, lactic acidosis (fatigue, nausea, acidosis)

WATCH

CBC weekly (platelets, hemoglobin, WBC), symptoms of serotonin syndrome (if on serotonergic drugs), visual symptoms (blurred vision, color vision changes — check Snellen and color vision), blood pressure (hypertensive crisis with tyramine)

CDSCO approvedSchedule H1Jan AushadhiNPPA price-controlledATC J01XX08

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 23min · absorption onset
PEAK: 1.5h · 1-2 h (oral/IV)
t½: 6h · 5-7 h (adults)
DURATION: 12h · 12 h (q12h dosing)

EXCRETION

~65% urine (parent + metabolites); ~30% fecal; non-CYP

route + CYP

INTERACTIONS

12 major

incl. contraindicated

PREGNANCY

FDA PLLR: Animal studies showed no teratogenicity. Limited human data. Use only if benefit clearly outweighs risk. Crosses placenta.

FDA category + note

Top interactionssee all 12 →

DuloxetineContraindicatedDatabaseDDInter
EscitalopramContraindicatedDatabaseDDInter
FluoxetineContraindicatedDatabaseDDInter
Serotonergic AgentsContraindicatedDatabaseKimi deep-research + Cla · p1187

Available in India

538 branded formulations and 3 fixed-dose combinations. Look up specific brands in the Drugs workspace.

Jan Aushadhi — generic available at GoI pharmacies

Mechanism

Linezolid is a synthetic oxazolidinone antibiotic that inhibits bacterial protein synthesis through a unique mechanism. It binds to the 23S ribosomal RNA of the 50S subunit at a site that prevents formation of the functional 70S initiation complex — the complex required for translation initiation. This mechanism is distinct from other protein synthesis inhibitors (which typically block elongation), making linezolid effective against organisms resistant to other antibiotic classes. It is bacteriostatic against most susceptible organisms but bactericidal against Streptococcus pneumoniae. Linezolid is also a weak, reversible, non-selective monoamine oxidase inhibitor (MAOI), which accounts for its serotonergic and hypertensive drug interactions.

Indications

Vancomycin-resistant Enterococcus faecium (VRE) infectionsNosocomial pneumonia (including MRSA)Community-acquired pneumonia (including MRSA)Complicated skin and skin structure infections (cSSSI) including diabetic foot infections without osteomyelitisUncomplicated skin and skin structure infectionsMRSA infections (alternative to vancomycin — better tissue penetration, oral bioavailability)Mycobacterial infections (off-label, including MDR-TB)

Dosing

Adult: VRE: 600 mg PO/IV q12h x 14-28 days. Pneumonia/cSSSI: 600 mg PO/IV q12h x 10-14 days. Uncomplicated SSSI: 400-600 mg PO q12h x 10-14 days. MDR-TB (off-label): 600 mg daily or 300 mg BID.
Pediatric: Neonates <7 days: 10 mg/kg IV/PO q12h. ≥7 days to <12 years: 10 mg/kg IV/PO q8h (max 600 mg/dose). 12+ years: 600 mg PO/IV q12h.
Renal adjustment: No adjustment required (primarily non-renal elimination). Not removed by hemodialysis.
Hepatic adjustment: No adjustment required (minimal hepatic metabolism).
Geriatric: No specific adjustment. Monitor for myelosuppression and serotonergic effects.
Max dose: 600 mg q12h (1200 mg/day)

Pharmacokinetics

Onset

Rapid bacteriostatic effect; clinical response within 48-72 hours.

Peak effect

Oral/IV: peak plasma at 1-2 hours. Oral bioavailability ~100% (no adjustment needed when switching IV to PO).

Duration

12 hours (supports q12h dosing).

Half-life

~5-7 hours (adults); 1.5-5 hours (pediatrics).

Bioavailability

~100% (oral; identical to IV exposure).

Protein binding

~31% (low; bound to albumin).

Metabolism

Minimal hepatic metabolism via non-enzymatic oxidation (morpholine ring oxidation to aminoethoxyacetic acid metabolite — inactive). No CYP enzyme involvement.

Excretion

Non-renal: ~65% as parent drug and metabolites in urine (30% unchanged, 50% metabolites). Fecal: ~30%. Not dialyzable.

Contraindications

Hypersensitivity to linezolid or any component
MAOI use within 14 days (or within 2 weeks of discontinuing linezolid before starting MAOI)
Pheochromocytoma or uncontrolled hypertension (MAOI activity can precipitate hypertensive crisis)
Thyrotoxicosis
Concurrent use with serotonergic agents (SSRIs, SNRIs, TCAs, triptans, meperidine) — unless close monitoring and no alternatives

Side effects

Common

Diarrhea, nausea, vomitingHeadacheInsomniaTaste alteration (metallic taste)RashFungal infections (oral/vaginal candidiasis)

Serious

Myelosuppression (thrombocytopenia, anemia, leukopenia/pancytopenia — dose- and duration-related; >2 weeks increases risk significantly; reversible on discontinuation)
Serotonin syndrome (with serotonergic drugs — hyperthermia, agitation, myoclonus, autonomic instability, altered mental status)
Peripheral and optic neuropathy (irreversible with prolonged use >28 days)
Lactic acidosis (mitochondrial toxicity — rare but life-threatening)
Hypertensive crisis (with tyramine-rich foods or sympathomimetics due to MAOI activity)
Clostridioides difficile-associated diarrhea
Seizures (rare)

Pregnancy & lactation

Pregnancy

FDA PLLR: Animal studies showed no teratogenicity. Limited human data. Use only if benefit clearly outweighs risk. Crosses placenta.

Lactation

Excreted in breast milk. Due to potential for serious adverse reactions in nursing infants, breastfeeding should be discontinued during linezolid therapy.

Drug interactions

Duloxetine

Contraindicated

Database

Serotonin syndrome risk.

Contraindicated. Use alternative antibiotic.

Source: DDInter

Escitalopram

Contraindicated

Database

Serotonin syndrome risk.

Contraindicated. Use alternative antibiotic.

Source: DDInter

Fluoxetine

Contraindicated

Database

Serotonin syndrome risk.

Contraindicated. Fluoxetine has long half-life; allow 5 weeks washout.

Source: DDInter

Serotonergic Agents

Contraindicated

Database

Linezolid is a weak reversible MAOI. Combined with serotonergic drugs, it can precipitate serotonin syndrome — a potentially fatal condition characterized by hyperthermia, autonomic instability, altered mental status, and neuromuscular abnormalities.

Avoid concurrent use. If linezolid essential for infection, discontinue serotonergic agents 2 weeks before (5 weeks for fluoxetine). Monitor for serotonin syndrome for 2 weeks after stopping linezolid.

Source: Kimi deep-research + Cla · p1187

Sertraline

Contraindicated

Database

Serotonin syndrome: hyperthermia, rigidity, myoclonus, mental status changes.

Do not combine. Stop SSRI 2 weeks before linezolid or use alternative antibiotic.

Source: DDInter

Venlafaxine

Contraindicated

Database

Serotonin syndrome risk.

Contraindicated. Use alternative antibiotic.

Source: DDInter

Adrenergic Drugs

Severe

Textbook

Potential for adverse effects related to MAO inhibition.

Avoid co-administration or monitor closely.

Source: KDT 7e · p758

Serotonergic Drugs

Severe

Textbook

Potential for adverse effects related to MAO inhibition (e.g., serotonin syndrome).

Avoid co-administration or monitor closely.

Source: KDT 7e · p758

Adalimumab

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Adrenergic Agents

Severe

Database

Linezolid's MAOI activity prevents breakdown of catecholamines. Sympathomimetics can precipitate hypertensive crisis (severe hypertension, headache, intracranial hemorrhage, death).

Avoid sympathomimetic decongestants and vasopressors if possible. If vasopressors essential, use lowest doses and monitor BP continuously.

Source: Kimi deep-research + Cla · p1187

Alfentanil

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Almotriptan

Severe

Database

Drug interaction classified as: synergy

Source: DDInter