Linezolid monitoring

Linezolid is of the oxazolidone class of antibiotics and is prescribed for serious Gram-positive bacterial infections, including resistant infections such as those due to coagulase-negative staphylococci, MRSA and glycopeptide-resistant enterococci. It has no direct activity against Gram-negative bacteria.

A unique, and clinically useful, characteristic of Linezolid is that it is 100% bioavailable by the oral route (i.e. 100% of the drug is absorbed by the gastrointestinal tract and enters the blood).

Absorption is not affected by food, although large amounts of tyramine-rich foods (such as mature cheese, salami, pickled herring, Bovril®, Oxo®, Marmite® or any similar meat or yeast extract or fermented soya bean extract, and some beers, lagers or wines) should be avoided.

Therapeutic concentrations are achieved in many body tissues.

In Hull, because our OPAT service is predominantly an outpatient model, we have found it a very useful antibiotic in facilitating the discharge from hospital, or outpatient treatment, of patients who are unable to attend daily or thrice weekly OPAT for a variety of reasons:

• less mobile or wheelchair-bound
• travelling from afar
• do not have relatives or friends who can transport them daily or thrice weekly to clinic
• live in challenging social circumstances
• are unsuitable or refuse OPAT for other reasons

In our experience, very few patients refuse or are unable to attend the COPAT service once weekly for Linezolid (or other antimicrobial regimen) monitoring.

Selected intravenous drug users, who we would not have offered OPAT to, have adhered to weekly complex oral antibiotic therapy monitoring; for those taking opiates with Linezolid, however, awareness of and monitoring for serotonin syndrome is required.

Linezolid is an antibiotic that mandates weekly monitoring due to the potential for serious AEs.

It does not require dose adjustment for renal or hepatic impairment, although patients with severe renal impairment are likely to be at higher risk for Linezolid induced anaemia/thrombocytopenia, particularly if anaemic/thrombocytopenic at the time of prescribing (as in the patient described in step 2.8).

Please find further reading in the see also section below.