Elevated vancomycin trough concentration: increased efficacy and/or toxicity?

Vancomycin susceptibility of methicillin-resistant Staphylococcus aureus has been changed over time and its average minimum inhibitory concentration increased from 1.5 to 1.75 mg/L.A recently published guideline by the American Society of Health Pharmacist recommended a daily dose of 15-20 mg/Kg every 8 to 12 hours of vancomycin to achieve a trough concentration between 15-20 mg/L for treatment of severe infections. Medical records of 69 patients from infectious ward of Imam Khomeini hospital, with suspected or confirmed gram-positive infection who had at least one trough level of vancomycin, were evaluated regarding vancomycin therapeutic goal; efficacy and renal safety. Most of patients [60.6%] with severe infections did not achieve the recommended vancomycin trough level during treatment course. Time to normalization of the signs and symptoms of infection did not correlate with the patients' serum vancomycin trough levels. At the end of treatment course, there was no significant correlation between patients' creatinine clearance and vancomycin trough levels [P=0.32]. However, patients'cratinine clearance showed a negatively significant correlation with trough level of vancomycin [P=0.01]. Vancomycin induced nephrotoxicity was detected in 4.3% of the patients. These data showed that vancomycin trough level may not necessarily assure treatment success, and also it would not essentially predict the risk of vancomycin induced nephrotoxicity. However, more well designed studies with larger sample size needed for better clinical and practical judgment

Adherence to empiric antibiotic therapy guideline in a referral teaching hospital, Tehran, Iran

Antibiotic guidelines have proven to be a simple and effective intervention to guide the choice of appropriate empiric antibiotic regimens. The goals of this study were to evaluate adherence to guidelines and streamlining of antibiotics. Hospital records of hospitalized patients in infectious diseases ward Imam Khomeini Hospital, Tehran, Iran, from May 2008 to September 2009 were reviewed. Adherence to guideline was defined as the use of empiric antibiotic in accordance with the clinical diagnosis and local guideline recommendations. In this study, 528 patients with a confirmed infectious disease diagnosis were considered for analysis. The four most frequent diagnoses were skin and soft tissue infections, tuberculosis, respiratory tract infections, and HIV associated opportunistic infections. The most frequent prescribed antibiotic was ceftriaxone. Overall adherence to guideline was 70.8% and the adherence for the most frequent diagnosis was 68%. Frequency of compatibility with the guidelines for were administrated regimes on the basis of drug selection, dosage form and drug dosing were 86.2%, 97% and 84.7%, respectively. The mean lag time between patients' hospital admission and starting empiric therapy was 1.69 +/- 4.9 days. In general, physicians' adherence with guidelines for empiric antibiotic therapy was high in infectious disease ward with a justified delay. Larger studies are required to establish these conclusions