Polymyxin B clinical outcomes: A prospective study of patients undergoing intravenous treatment

Abstract

Summary What is known and objective Polymyxins, especially polymyxin B, has become the last line of therapy against Gram‐negative pathogens’ carbapenemase producers. However, given increasing use of polymyxin B in clinical settings its therapeutic value has been evaluated worldwide due to its toxic effects. The aim of this study was to assess the efficacy and safety of antimicrobial therapy with polymyxin B in patients with multidrug‐resistant bacteria in Brazil. Methods This was a prospective cohort study in a 403‐bed academic tertiary care centre, located in the countryside of Brazil. Patients receiving polymyxin B intravenous treatment for at least 72 hours were eligible for the study. Antimicrobial susceptibility, adverse reactions and clinical outcomes were submitted for descriptive analysis. Main outcomes measure the following: Patients' conditions following treatment (Treatment Success, Mortality, Treatment Failure, Inadequate Empiric Treatment or Indeterminate Response) and toxicities induced by polymyxin B (nephrotoxicity and skin hyperpigmentation). Results and discussion Among 247 patients, treatment success was achieved in 25.1%, while mortality was observed in 32.8%. Empirical therapy was prescribed for 26.3% of the patients. Nephrotoxicity was reported in 40.5%. The carbapenemase producer, Klebsiella pneumonia, was the bacterium most associated with mortality (22.2%). Conclusions Even though polymyxin B is currently the main therapy against carbapenemase producers, its use demands robust criteria to lead to positive clinical outcomes.

A Real-World Study for Polymyxin B in the Treatment of Carbapenems Resistant Gram-Negative Bacilli

“…Nephrotoxicity occurred in 7 cases (7%) were mild and reversible, none required renal replacement therapy. The prevalence of nephrotoxicity was not lower in our study than in observational studied (6-40.5%) [11,[26][27][28]. Assessing of the contribution of PMB to renal impairment di cult.…”

“…Besides, 3 cases (3%) developed skin hyperpigmentation in the face and neck, found no effect from skin hyperpigmentation on the e cacy of PMB. The incidence is lower than previous studies [26]. During treatment, there were no other adverse reactions such as rashes, itching, dermatitis, drug fever, etc.…”

“…Yet another study, however, none of the cases occurred neurotoxicity complications among 247 patients who were therapy with PMB in Brazil [26]. Besides, 3 cases (3%) developed skin hyperpigmentation in the face and neck, found no effect from skin hyperpigmentation on the e cacy of PMB.…”

Clinical Effects of Polymyxin B in Patients infected with Carbapenem-resistant organisms

“…[26] The prevalence of total adverse effects was 11.4% in our study. The prevalence of nephrotoxicity was 4.2%, which is lower than that in the study by Mattos and colleagues (40.5%), [27] Oliveira and co-workers (26.8%), [28] and Agarwal and collaborators (11.8%). [6] PMB neurotoxicity is caused mainly by inhibition of acetylcholine in neuromuscular junctions and PMB reabsorption by renal-cell receptors, but the overall mechanism is not known.…”

“…The prevalence of skin hyperpigmentation was 1.6% in our study, which is lower than that reported by Mattos and colleagues (8.1%). [27] The reasons for pigmentation/darkening of skin vary, but the most common reason is melanin production in skin cells (especially in dermal macrophages). [31] Our study had four main limitations.…”