In clinical practice, intermittent antibiotic dosing has been mostly, but not unequivocally successful in eradicating bacterial growth (33,159,179–182). In a pediatric trial comparing intermittent and continuous intraperitoneal administration of empiric glycopeptide and ceftazidime, persistent growth of the causative organism in dialysate was found in 33% and 10% of the intermittently treated episodes and in 6% and 1% of the continuously treated episodes after 60 hours and after 7 days of treatment respectively (159). Delayed eradication with intermittent therapy was found not to affect overall treatment outcomes, but a higher rate of clinical treatment failure was observed in patients with gram-negative peritonitis receiving intermittent ceftazidime. The inferior efficacy of once-daily ceftazidime in gram-negative peritonitis was confirmed in the IPPR registry, where intermittent therapy was independently associated with a risk of empiric treatment failure that was higher by a factor of 14 (33).