One of the ideas behind creating this blog was to be able to keep readers apprised of any new, interesting papers published in the infectious diseases and microbiology literature I follow on a regular basis. For background I will tell you that my 3 top journals include:
Clinical Infectious Diseases (CID) – put out by the Infectious Diseases Society of America www.idsociety.org and my favorite clinical ID journal.
Journal of Infectious Diseases (JID) – also an IDSA journal. Mostly HIV and intense basic research but does occasionally publish in interesting review or bacteriology manuscript.
Antimicrobial Agents and Chemotherapy (AAC) – this journal, published by the American Society for Microbiology asm.org is the best source for new antibiotic research and clinical microbiology
I periodically also receive manuscript files sent to me by a network of ID friends and colleagues.
Although I try to review each as they are received I admit that, occasionally, they get lost in a pile on my desk. Because of prior commitments, I admit that this is what has happened over the past 3 months and I have been remiss in my reviewing of these back issues. So, to bring folks up to speed, here are a few papers of relatively recent vintage that I find interesting.
Thomas Lodise, et. al. Relationship between initial vancomycin concentration – Time profile and nephrotoxicity among hospitalized patients. CID, August 15, 2009. Tom Lodise’s pharmacology group from Albany has been doing some terrific work looking at nephrotoxicity of vancomycin given recent recommendations to increase trough levels to between 15-20mg/L. Just last year in AAC they published their findings that bumping vanco doses to 4 grams/day (sometimes necessary to achieve these higher peaks) was associated with a significantly higher rate of nephrotoxicity. In this study they concluded that “The results indicate that a vancomycin exposure – toxicity response relationship exists. The vancomycin trough value is the pharmacodynamic index that best describes this association.” I have blogged about this vancomycin dosing issue in the past. Maybe I am being selective about what I read and share but I still have issues with this concept of bumping vanco trough levels especially given the total lack of data in diabetic foot infections where the patients may already have compromised kidneys.
Micheal Ryback, et. al. Vancomycin Therapeutic Guidelines: A summary of consensus recommendations from the IDSA, the American Society of Health System Pharmacists and the Society of Infectious Diseases Pharmacists. CID, August 1, 2009. Perhaps I should have listed this article before the one above since this summarizes the guidelines that promote this new dosing regimen and the concept of achieving an AUC/MIC ratio of >400 by using weight based dosing and bumping troughs. Considering the attention given to these new guidelines my readership should become very familiar with them. The full, original document can be accessed at http://www.ashp.org/DocLibrary/BestPractices/TPSVanco.aspx
Shveta Rani Singh, et. al. In vitro 24-hour time-kill studies of vancomycin and linezolid in combination versus methicillin resistant Staphylococcus aureus. AAC Oct. 2009. This title is a perfect example of what one can expect reading AAC. Once you get past the wordy titles there is some great information. I found this interesting because, apparently, there are clinicians trying all different antibiotic combinations to fight MRSA. The authors found that there was no synergy at all, and, in fact, frank antagonism occurred in 3 out of 5 strains when linezolid was added to vancomycin. The bottom line…try other combinations if you must, just not this one.
Stan Deresinski. Vancomycin in combination with other antibiotics for the treatment of serious MRSA infections. CID Oct 1, 2009. Stan Deresinski out of Stanford University has become a bit of a “go to guy” when it comes to MRSA and the ID community. I urge all of my readers to find his 2005 CID review paper Methicillin-Resistant Staphylococcus aureus: An Evolutionary, Epidemiologic,and Therapeutic Odyssey which remains one of the most easily digestible treatises on the topic. In this more recent review he scans the literature to find support of the commonly employed practice of combining vancomycin with a second antibiotic usually rifampin or gentamicin and finds to supportive evidence for these combinations but known potential toxicities.
Jose L. Del Pozo, et al. The electricidal effect is active in an experimental model of Staphylococcus epidermidis chronic foreign body osteomyelitis. AAC Oct. 2009. This interesting rabbit study compared low amperage (200 µA) electrical current to IV doxycycline treatment to no treatment for foreign body osteomyelitis in the rabbit tibia. As expected, both treatment groups were significantly better than the no treatment group. Interestingly, the electrical current group was significantly more efficacious than the doxycycline group. They feel that this might be related to the activity of the current against the bacterial biofilms. This entire area of bioflims as determining factors in the treatment of chronic infections is fascinating and bears watching.
Let me know what you think of the concept of writing up these reviews, and please suggest other papers you would like to hear my opinion about