Rational use of intravenous polymyxin B and colistin: A review

@#Polymyxin B and colistin (polymyxin E) were introduced in clinical practice to treat Gram-negative infections in 1950s but their parenteral use waned in 1970s due to toxicity concerns. Resurgence of polymyxins use in Malaysia began approximately in 2009 due to a lack of treatment options for MDR Gram negative superbugs such as Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. However, limited experience and a lack of widespread availability of up-to-date dosing guidelines could potentially result in incorrect use of these last resort antibiotics by managing doctors. The recent report of polymyxin resistant strains is also a cause of concern. Herein, we discuss the importance of preserving the efficacy of polymyxins in hospitals, the similarities and differences between polymyxin B and colistin, issues pertaining to current use of polymxyins and strategies to improve polymyxins’ prescription. Polymyxins should only be used to treat significant infections, in optimum doses and if possible, in combination with other antibiotics.

The Multidrug-Resistant Gram-negative Superbug Threat Requires Intelligent Use of the Last Weapon

The global emergence and dissemination of multidrug-resistant Gram-negative superbugs, particularly carbapenem-resistant Acinetobacter baumannii and Klebsiella pneumoniae, lead to the limited effectiveness of antibiotics for treating nosocomial infections. In most cases, polymyxins are the last resort therapy, and these antibiotics must be used intelligently to prolong their efficacy in clinical practice. Polymyxin B and colistin (polymyxin E) were introduced prior to modern drug regulation, and the majority of the ‘old’ drug information is unreliable. Recent pharmacokinetic data do not support the renal dose adjustment of intravenous (IV) polymyxin B as suggested by the manufacturer, and this drug must be scaled by the total body weight. Whereas IV colistin is formulated as an inactive prodrug, colistin methanesulfonate (CMS) has different pharmacokinetic profiles than polymyxin B. To achieve maximum efficacy, CMS should be administered as a loading dose scaled to body weight and a maintenance dose according to the renal profiles. Polymyxin combination therapy is suggested due to a sub-therapeutic plasma concentration in a significant proportion of patients and a high incidence of polymyxin hetero-resistance among Gram-negative superbugs. In conclusion, polymyxins must be reserved as a last resort and should be wisely used when truly indicated

Excellent outcome of primary Neisseria meningitidis keratoconjunctivitis

Infectious conjunctivitis is a very common presentation to medical professional and ophthalmologist all over the world. Although its typically self-limiting and treatable in almost all of the cases, but we need to be aware of the rare and potentially life threatening if the cause is not promptly identified and treated accordingly. In our case report, we highlighted the rare case of Neisseria meningitidis as a primary cause of keratoconjunctivitis. Neisseria meningitidis is a rare etiology of keratoconjunctivitis and its ocular presentations are quite similar with other bacterial or viral infection. The infection may potentially fatal if systemic invasion occurred, however with immediate and proper treatment the outcome is satisfactory. Early diagnosis and proper antibiotic treatment are critical to prevent systemic spread of the infection. Public health intervention is needed to prevent outbreak of the disease.

Risk factors and outcomes of imipenem-resistant Acinetobacter bloodstream infection in North-Eastern Malaysia

<p><b>OBJECTIVE</b>To determine the risk factors and outcomes of imipenem-resistant Acinetobacter baumannii (IRAB) bloodstream infection (BSI) cases, since there is very little publication on Acinetobacter baumannii infections from Malaysia.</p><p><b>METHODS</b>A cross sectional study of 41 cases (73.2%) of imipenem-sensitive Acinetobacter baumanii (ISAB) and 15 cases (26.8%) of IRAB was conducted in a teaching hospital which was located at North-Eastern state of Malaysia.</p><p><b>RESULTS</b>There was no independent risk factor for IRAB BSI identified but IRAB BSI was significantly associated with longer bacteraemic days [OR 1.23 (95% CI 1.01, 1.50)]. Although prior use of carbepenems and cephalosporin were higher among IRAB than ISAB group, statistically they were not significant. There was no significant difference in term of outcomes between the two groups.</p><p><b>CONCLUSIONS</b>Although statistically not significant, this analysis compliments previous publication highlighting the importance of appropriate empiric antibiotic usage in hospital especially carbepenems and need further evaluation with bigger subjects.</p>