Antimicrobials/Glycopeptide & anti-MRSA

Glycopeptides & anti-MRSA agents

also: vancomycin · teicoplanin · linezolid · daptomycin · MRSA

Overview

Gram-positive agents reserved largely for MRSA and severe Gram-positive infection (and oral vancomycin for C. difficile).

Mechanism

Glycopeptides (vancomycin/teicoplanin) inhibit cell-wall synthesis (bind D-Ala-D-Ala). Linezolid (oxazolidinone) inhibits the 50S ribosome. Daptomycin disrupts the cell membrane.

The agents

Vancomycinglycopeptide

IV (levels); ORAL for C. diff

MRSA, severe Gram+ in penicillin allergy; oral = 1st-line C. difficile.

Teicoplaninglycopeptide

once-daily

As vancomycin, easier dosing.

Linezolidoxazolidinone

100% oral

MRSA/VRE; serotonin syndrome with SSRIs/MAOIs; myelosuppression + optic neuropathy if >2 weeks.

Daptomycinlipopeptide

MRSA bacteraemia/endocarditis; INACTIVATED by surfactant → NOT for pneumonia; myopathy (stop statin, monitor CK).

Adverse effects

Vancomycin: nephrotoxicity, "red man" infusion reaction (slow rate)serious

Linezolid: serotonin syndrome, myelosuppression, optic neuropathyserious

Daptomycin: myopathy (CK)serious

Cautions & contraindications

Daptomycin for pneumoniaall

Inactivated by pulmonary surfactant.

Linezolid with serotonergics/MAOIsall

Serotonin syndrome.

Interactions

Vancomycin + aminoglycosides (nephro/ototoxicity); linezolid + serotonergics

Monitoring & kinetics

Vancomycin levels + renal function; linezolid FBC if >2 weeks; daptomycin CK

IV (oral vancomycin only for C. diff; linezolid fully oral). Reserve / stewardship.

Choosing it

Spectrum: Gram-positive ONLY, including MRSA (vancomycin, teicoplanin, linezolid, daptomycin) and VRE (linezolid, daptomycin). Oral vancomycin: C. difficile (not absorbed).

Source: BNF — Glycopeptides / MRSA