Nuevos antibióticos frente a grampositivos: linezolid, tigeciclina, daptomicina, dalbavancina, telavancina, ceftobiprole | Enfermedades Infecciosas y Microbiología Clínica

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En los últimos años se han desarrollado 6 nuevos antibióticos activos frente a bacterias grampositivas, 3 de los cuales ya están disponibles para uso clínico. Uno de estos fármacos es un antibiótico de síntesis completamente nuevo (linezolid). Otro es una lipopeptidolactona, derivado semisintético de una especie de Streptomyces (daptomicina). El resto consiste en modificaciones de tetraciclinas (tigeciclina), glucopéptidos (dalbavancina y telavancina) o cefalosporinas (ceftobiprole). Lo más relevante de estos antibióticos es su actividad frente a organismos grampositivos, incluidos Staphylococcus aureus resistente a la meticilina, S. aureus con sensibilidad intermedia a la vancomicina, y enterococos sensibles y resistentes a la vancomicina. Alguno de ellos (linezolid, tigeciclina y ceftobiprole) posee, además, actividad frente a bacterias gramnegativas. Cuatro de ellos (daptomicina, dalbavancina, telavancina y ceftobiprole) poseen un efecto generalmente bactericida. Todos estos antibióticos se administran por vía intravenosa en infusión continua, aunque linezolid, debido a su excelente biodisponibilidad, puede también administrarse por vía oral. Las dosis recomendadas para el adulto son muy variadas (de 100 a 1.500mg/día), con intervalos que van desde las 12h (linezolid, tigeciclina y ceftobiprole), 24h (daptomicina y telavancina) o 7 días (dalbavancina). Estos antibióticos se eliminan, predominantemente, por vía renal (daptomicina, dalbavancina, telavancina y ceftobiprole) o hepática (linezolid y tigeciclina). Los índices farmacodinámicos que se correlacionan con eficacia terapéutica, teniendo en cuenta siempre la fracción libre del antibiótico, es la tasa área bajo la curva/concentración mínima inhibitoria (CMI) (linezolid, tigeciclina, daptomicina, dalbavancina y telavancina) o el tiempo en que la concentración sérica del antibiótico supera la CMI del patógeno (ceftobiprole).

Palabras clave:

Linezolid

Tigeciclina

Daptomicina

Dalbavancina

Telavancina

Ceftobiprole

Six new antibiotics against Gram-positive bacteria have been developed in the last few years, three of which are already available for clinical use. One of these drugs is a completely new synthetic antibiotic (linezolid). Another is a semisynthetic lipopeptide derived from a species of Streptomyces (daptomycin). The remaining agents are modifications of tetracyclines (tigecycline), glycopeptides (dalbavancin and telavancin) or cephalosporins (ceftobiprole). The most important feature of these antibiotics is their activity against Gram-positive organisms, including methicillin-resistant Staphylococcus aureus, vancomycin-intermediate S. aureus, and vancomycin-resistant and -sensitive enterococci. Some of these agents (linezolid, tigecycline and ceftobiprole) are also active against Gram-negative bacteria. Four of these (daptomycin, dalbavancin, telavancin and ceftobiprole) have a general bactericidal effect. All of these antibiotics are administered intravenously by continuous infusion, although linezolid, due to its excellent bioavailability, can also be administered orally. The recommended doses for adults are highly varied (from 100 to 1500mg/day), with intervals ranging from 12hours (linezolid, tigecycline and ceftobiprole), 24hours (daptomycin and telavancin) to 7 days (dalbavancin). These antibiotics are mainly excreted through the kidney (daptomycin, dalbavancin, telavancin and ceftobiprole) or liver (linezolid and tigecycline). The pharmacodynamic indexes that are correlated with therapeutic efficacy, always bearing in mind the free antibiotic fraction, is the area AUC /MIC ratio (linezolid, tigecycline, daptomycin, dalbavancin and telavancin) or the time in which the serum concentration of the antibiotic is above the MIC of the pathogen (ceftobiprole).

Key words:

Linezolid

Tigecycline

Daptomycin

Dalbavancin

Telavancin

Ceftobiprole

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