Recent developments in antibiotic agents for the treatment of complicated intra-abdominal infections.

Introduction: Treatment of complicated intra-abdominal infections (cIAIs) is becoming increasingly difficult because of the widespread emergence of multidrug-resistant organisms.Areas covered: In this review, we discuss the effectiveness of several new antibiotics for the treatment of cIAIs, including new -lactamase inhibitor combinations (BLICs) and tetracycline-class drugs, recently developed aminoglycosides and quinolones, and novel lipoglycopeptides and oxazolidinones.Expert opinion: Of the new BLICs, ceftolozane/tazobactam is associated with adequate clinical cure rates in patients with cIAIs. Currently, two new -lactamase inhibitors, namely avibactam and MK-7655, are under development for clinical use in the treatment of cIAIs. Eravacycline, a novel, fully synthetic tetracycline-class drug, has been shown in Phase II and III clinical trials to be more potent than tigecycline against a significant number of multidrug-resistant organisms causing cIAIs. Plazomicin, a next-generation aminoglycoside, is a promising agent for treatment of cIAIs due to multidrug-resistant pathogens. Of the recently developed quinolones, delafloxacin and finafloxacin have been shown to be effective against pathogens that survive and multiply in mildly acidic environments, although further clinical studies examining their clinical utility in the treatment of cIAIs are warranted. Oritavancin, a new semisynthetic lipoglycopeptide agent, has been demonstrated to be a potent antibiotic in the treatment of cIAIs due to drug-resistant Gram-positive organisms. Several other new antibiotics in development also show promise and will hopefully broaden the possibilities for treatment of complicated intra-abdominal infections due to MDR pathogens.