Dear Editor,
We read with great interest the case report by Falcone et al. on the treatment of Spontaneous Bacterial Peritonitis (SBP) due to methicillin-resistant Staphylococcus aureus (MRSA) with high vancomycin minimum inhibitory concentration (MIC) value.1 The authors treated a SBP (microbiological results of ascites fluid showed MRSA) in a cirrhotic patient with a documented allergy to tetracycline with daptomycin (6 mg/kg/day) for 12 days.
Tigecycline, a glycylcycline licenced for the treatment of intra-abdominal infections (IAI),2 unlike daptomycin, that is effective against MDR Gram-positive bacteria, including MRSA and vancomycin-resistant enterococci (VRE) was contraindicated because of the documented allergy to tetracyclines.
The authors state that the linezolid can not be used in the majority of patients with cirrhosis and bacterial infections because of myelotoxicity and thrombocytopenia. Indeed thrombocytopenia is a long term (over two weeks of therapy) reversible adverse effect;3 however duration of SBP antibiotic treatment is unclear;4 treatment for 5 days has shown success and longer treatment is recommended if blood cultures are positive.5
Furthermore, daptomycin is associated with higher all-cause mortality and trend for higher relapse rate than linezolid.6 Daptomycin displays a dose-dependent response against VRE with high-dose daptomycin (10-12 mg/kg/day) producing most bactericidal activity,7 and a daptomycin dosage of 8 mg/kg/day or greater may be safe in patients with complicated gram-positive infections.8 So in other life-threatening setting such as infective endocarditis, patients had successful outcomes with high-dose daptomycin therapy.9
Finally, several reports have linked increases in vancomycin MICs to increases in daptomycin MICs and thus high-dose daptomycin should be in place of standard dosing.10,11
In conclusion, according to current evidence the low-dose daptomycin used in the case report does not seem to be the best therapeutic choice for the treatment of gram-positive SBP.
References
- 1.Falcone M, Russo A, Pacini G, et al. Spontaneous bacterial peritonitis due to methicillin-resistant Staphylococcus aureus in a patient with cirrhosis: the potential role for daptomycin and review of the literature. Infect Dis Rep 2015;7:6127. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Eckmann C, Montravers P, Bassetti M, et al. Efficacy of tigecycline for the treatment of complicated intra-abdominal infections in real-life clinical practice from five European observational studies. J Antimicrob Chemother 2013;68:ii25-35. [DOI] [PubMed] [Google Scholar]
- 3.Wu VC, Wang YT, Wang CY, et al. High frequency of linezolid-associated thrombocytopenia and anemia among patients with end-stage renal disease. Clin Infect Dis 2006;42:66-72. [DOI] [PubMed] [Google Scholar]
- 4.Esposito S, Esposito I, Leone S. Considerations of antibiotic therapy duration in community- and hospital-acquired bacterial infections. J Antimicrob Chemother 2012;67:2570-5. [DOI] [PubMed] [Google Scholar]
- 5.Alaniz C, Regal RE. Spontaneous bacterial peritonitis: a review of treatment options. Pharm Therapeut 2009;34:204-10. [PMC free article] [PubMed] [Google Scholar]
- 6.Balli EP, Venetis CA, Miyakis S. Systematic review and meta-analysis of linezolid versus daptomycin for treatment of vancomycin-resistant enterococcal bacteremia. Antimicrob Agents Chemother 2014;58:734-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Hall AD, Steed ME, Arias CA, et al. Evaluation of standard- and high-dose daptomycin versus linezolid against vancomycin-resistant Enterococcus isolates in an in vitro pharmacokinetic/pharmacodynamic model with simulated endocardial vegetations. Antimicrob Agents Chemother 2012;56:3174-80. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Kullar R, Davis SL, Levine DP, et al. High-dose daptomycin for treatment of complicated gram-positive infections: a large, multicenter, retrospective study. Pharmacotherapy 2011;31:527-36. [DOI] [PubMed] [Google Scholar]
- 9.Kullar R, Casapao AM, Davis SL, et al. A multicentre evaluation of the effectiveness and safety of high-dose daptomycin for the treatment of infective endocarditis. J Antimicrob Chemother 2013;68:2921-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Patel JB, Jevitt LA, Hageman J, et al. An association between reduced susceptibility to daptomycin and reduced susceptibility to vancomycin in Staphylococcus aureus. Clin Infect Dis 2006;42:1652-3. [DOI] [PubMed] [Google Scholar]
- 11.Murray KP, Zhao JJ, Davis SL, et al. Early use of daptomycin versus vancomycin for methicillin-resistant Staphylococcus aureus bacteremia with vancomycin minimum inhibitory concentration >1 mg/L: a matched cohort study. Clin Infect Dis 2013;56:1562-9. [DOI] [PubMed] [Google Scholar]