Adverse effects/interactions/contraindications

• adverse effects and contraindications
  • adverse effects include diarrhoea, headache, nausea and vomiting, metallic taste, candidiasis, abnormal liver function tests - there has also been reported cases of reversible anaemia and thrombocytopenia
  • adverse effects more likely in severe renal insufficiency; also haemoglobin and platelet count should be monitored in such patients and in those with pre-existing thrombocytopenia or anaemia, and in those who are being treated with other medication that can cause thrombocytopenia or anaemia or treatment duration with linezolid is for 10-14 days
  • severe optic neuropathy that has progressed to blindness has been reported rarely in patients treated with linezolid (2)
    • occurred primarily in patients who have received linezolid for longer than the maximum recommended duration of 28 days. In some cases, vision has been reported to recover after early withdrawal of the drug, but this process may take some months
      • physicians are advised to (2):
        • warn patients to immediately report any symptoms of visual impairment, including changes in visual acuity, changes in colour vision, blurred vision or visual field defect
        • ensure that any patient experiencing new visual symptoms, regardless of treatment duration, is promptly evaluated and, if necessary, referred to an ophthalmologist
        • regularly monitor the visual function of all patients who may require treatment for longer than the recommended 28 days
          
          
• linezolid is a reversible monoamine oxidase inhibitor - to help prevent linezolid-related excessive increase in blood pressure patients need to avoid foodstuffs (and drink) that is rich in tyramine (e.g. mature cheese, soy sauce)
  
  
• contraindications include patients taking (or within 2 weeks of stopping) drugs that result in inhibition of monoamine oxidase A or B (linezolid is a monoamine oxidase inhibitor)
  
  
• manufacturer states that, unless facilities available for observing closely patient and monitoring blood pressure then linezolid should not be co-administered with tricyclic antidepressants, serotonin-reuptake inhibitors, dopaminergic or vasopressive drugs, drugs which ae directly and indirectly sympathomimetic, buspirone, pethidine; also should not be used in patients with carcinoid tumour, thyrotoxicosis, uncontrolled hypertension, bipolar depression, acute confusional states, schizoaffective disorder

Reference:

1. Drug and Therapeutics Bulletin (2001); 39 (7): 54-6.
2. Current Problems in Pharmacovigilance (2006):31:1-12.