Zenix 600 mg film-coated tablets and 2 mg/mL solution for infusion – linezolid for pneumonia and severe skin infections

Zenix contains linezolid, an antibiotic from the oxazolidinone group that stops the growth of certain (Gram-positive) bacteria that cause infections. It is used to treat pneumonia and certain severe (complicated) infections of the skin and soft tissues in adults.

In Serbia it is authorised as Zenix 600 mg film-coated tablets (10 tablets) and Zenix 2 mg/mL solution for infusion (300 mL bottle), made by Hemofarm. Treatment is started in hospital; the tablets may exceptionally be dispensed on prescription to continue treatment at home.

What is Zenix used for and how should it be used?

Key facts about the medicine

What is Zenix used for?

• community-acquired and hospital-acquired (nosocomial) pneumonia in adults, when known or suspected to be caused by susceptible Gram-positive bacteria
• complicated skin and soft tissue infections in adults, only when microbiological testing has shown they are caused by susceptible Gram-positive bacteria

Linezolid is not active against Gram-negative bacteria. Treatment is started only in hospital, after consultation with a specialist (infectious disease specialist or microbiologist).

How is it used and dosed?

• Treatment usually lasts 10 to 14 days, and at most 28 days; the doctor decides on duration.
• Treatment can be started with the infusion and continued with tablets without changing the dose, as the bioavailability of the tablets is about 100%.
• Patients on haemodialysis receive the medicine after dialysis.
• Keep taking the medicine until your doctor tells you to stop, even when you feel better.

This is the general dosing from the leaflet – your doctor determines your dose and duration.

Special patient groups

• Children and adolescents under 18 years: not used (insufficient data).
• Elderly patients: no dose adjustment needed.
• Kidney impairment: no dose adjustment needed; in severe impairment and haemodialysis use with particular caution, the medicine is given after dialysis.
• Liver impairment: no dose adjustment needed, but with particular caution.
• The solution for infusion contains glucose (13.7 g in 300 mL) and sodium (114 mg in 300 mL) – important in diabetes and low-salt diets.

Contraindications – when the medicine must not be used

• allergy (hypersensitivity) to linezolid or any of the excipients
• concomitant use or use within the previous two weeks of monoamine oxidase inhibitors (MAOIs, e.g. phenelzine, isocarboxazid, selegiline, moclobemide)
• breast-feeding (the medicine passes into breast milk)

Warnings and precautions

• Tell your doctor if you have high blood pressure, an overactive thyroid, phaeochromocytoma or carcinoid syndrome, manic depression, schizoaffective disorder or other mental health problems, low blood sodium (or take diuretics), or take opioids.
• Particular caution in the elderly, with a tendency to bleeding and bruising, anaemia, a tendency to infections (possible fungal infection of the mouth or genitals), previous seizures, liver or kidney disease (especially dialysis) and diarrhoea.
• Contact your doctor immediately if you have vision problems, numbness or tingling in the hands and feet, diarrhoea that worsens or contains blood or mucus, repeated nausea or vomiting with abdominal pain and rapid breathing, or weakness, headache and confusion (possible low sodium).
• If you have diarrhoea, do not take medicines that slow down or stop bowel movement.
• The doctor checks your blood count weekly; depending on the results, treatment may be stopped.

Interactions with other medicines, food and drink

• MAO inhibitors – contraindicated (see above).
• The doctor assesses blood pressure and general condition or chooses another treatment if you take: decongestants and cold medicines with pseudoephedrine or phenylpropanolamine, salbutamol, terbutaline or fenoterol, tricyclic antidepressants or SSRIs (e.g. amitriptyline, citalopram, fluoxetine, paroxetine, sertraline), triptans (sumatriptan, zolmitriptan), adrenaline, noradrenaline, dopamine, dobutamine, pethidine, buspirone, warfarin or rifampicin.
• Antidepressants and opioids with linezolid can cause serotonin syndrome – a life-threatening condition.
• Food and drink: the medicine can be taken before, during or after meals, but avoid large amounts of mature cheese, yeast extract, soya bean extract (soy sauce) and alcohol, especially draught beer and wine (tyramine).

Pregnancy and breast-feeding

The effect of the medicine in pregnant women is not known, so it should not be taken during pregnancy unless your doctor advises otherwise. You must not breast-feed while taking Zenix, as the medicine passes into breast milk and may affect the baby.

Driving and using machines

Zenix may cause dizziness or vision problems. If these symptoms occur or you feel unwell, do not drive or use machines.

Possible side effects

• Common: fungal infections (vaginal or oral candidiasis), headache, metallic taste, diarrhoea, nausea, vomiting, changes in some lab results (liver, kidneys, sugar, electrolytes), insomnia, high blood pressure, anaemia, low platelet count, dizziness, abdominal pain, constipation, indigestion, rash, itching, fever.
• Uncommon: blurred vision, serious skin reactions, swelling of the face and neck, antibiotic-associated colitis, seizures, pancreatitis, transient ischaemic attacks, ringing in the ears, numbness or tingling, dry or sore mouth, tongue discolouration, more frequent urination, thirst, sweating, low sodium, kidney failure, bloating, fast pulse.
• Rare: restricted visual field, wheezing or difficulty breathing (allergy), purple rash due to inflamed blood vessels, repeated nausea and vomiting with rapid breathing, superficial tooth discolouration (removable by professional cleaning).
• Frequency not known: serotonin syndrome, changes in colour vision, hair loss. With treatment longer than 28 days, numbness, tingling and blurred vision have been reported.

Report suspected side effects to your doctor, pharmacist or ALIMS.

Overdose, missed dose and stopping treatment

• Overdose: if you have taken more tablets than prescribed, contact your doctor, pharmacist or the nearest healthcare facility immediately.
• Missed dose: take the forgotten tablet as soon as you remember, the next one 12 hours later, and continue every 12 hours; never take a double dose.
• Stopping treatment: continue until your doctor tells you to stop; if symptoms return after stopping, contact your doctor immediately.

Related information

For additional care and support in restoring gut flora during and after antibiotic treatment, see also the category Products with probiotics – products in this category do not replace the medicine prescribed for you.

Composition, pack and manufacturer

• Film-coated tablets – active substance: linezolid 600 mg; excipients: silicified and plain microcrystalline cellulose, sodium starch glycolate (type A), povidone K 90, magnesium stearate; coating: hypromellose, propylene glycol, titanium dioxide (E171), talc.
• Solution for infusion – 1 mL contains 2 mg linezolid; excipients: glucose monohydrate, sodium citrate, anhydrous citric acid, sodium hydroxide and hydrochloric acid (for pH adjustment), water for injections.
• Pack: 1 blister of 10 film-coated tablets; 1 glass bottle of 300 mL in protective aluminium foil.
• Marketing authorisation holder and manufacturer: HEMOFARM AD VRŠAC, Beogradski put bb, Vršac, Republic of Serbia.

Storage

• Film-coated tablets: no special storage conditions; shelf life 5 years.
• Solution for infusion: store in the original package (bottle in aluminium foil in the carton) to protect from light; do not freeze.
• Keep out of the sight and reach of children; do not use after the expiry date.

Frequently asked questions

Why should I avoid mature cheese and soy sauce while taking Zenix?

Linezolid can react with tyramine, which occurs naturally in mature cheese, yeast extract, soy sauce and some alcoholic drinks, and cause a rise in blood pressure. If you get a throbbing headache after a meal, contact your doctor.

How long does Zenix treatment last?

Usually 10 to 14 days, and at most 28 days. With treatment longer than 28 days, the doctor should also monitor your vision.

Are Zenix tablets taken with food?

They can be taken before, during or after meals; swallow the tablet whole with a little water, every 12 hours.

What should I do if I get diarrhoea?

Diarrhoea is a common side effect. If it worsens, lasts longer or you notice blood or mucus in the stool, contact your doctor immediately and do not take medicines that slow down the bowel.

Sources

• ALIMS – Summary of Product Characteristics, Zenix® 600 mg film-coated tablets (Serbian)
• ALIMS – Patient leaflet, Zenix® 600 mg film-coated tablets (March 2024, Serbian)
• ALIMS – Summary of Product Characteristics, Zenix 2 mg/mL solution for infusion (Serbian)
• ALIMS – Patient leaflet, Zenix 2 mg/mL solution for infusion (March 2021, Serbian)

Sources checked on: 24 October 2026.