Nonadherence to treatment recommendations is a factor contributing to the clinical failure of daptomycin: Cohort study in Brazil

To evaluate the clinical outcomes of daptomycin therapy and adherence to treatment recommendations, a retrospective cohort study was conducted with patients that received daptomycin during the period of the study. The adherence and nonadherence to clinical guidelines were assessed through organism identification, dose and time of treatment, management of bacteremia, and vancomycin treatment failure. A multiple logistic regression model analyzed the association between independent variables and clinical success (dependent variable), considering 5% of statistical significance. The study presented 52 patients who received daptomycin for the treatment of bacteremia (21.1%) or infections (osteomyelitis [63.5%], synovial fluid [15.4%]). Most patients (86.5%) received daptomycin as the second line of treatment, and 51.9% achieved clinical success. The patients had a better chance of clinical success when they followed the guideline indications (OR = 16.86; 95% CI = 1.45-195.88) and the medication was prescribed by a specialist in infectious diseases (OR = 4.84; 95% CI = 1.11-21.09). The study demonstrated lower clinical success than that described in the literature because of patients who were not eligible according to the clinical guidelines. Adherence to recommendations and appropriate prescription of reserve antibiotics is important in limiting early resistance, and avoiding clinical failure and unnecessary expenditure.

A fully validated microbiological assay for daptomycin injection and comparison to HPLC method

abstract Daptomycin (DPT) was the first lipopeptide antibiotic available for commercialization. It is active against gram-positive bacteria, including resistant strains. This work aimed to develop and validate a turbidimetric microbiologic assay to determine daptomycin in an injectable form. A 3x3 design was employed, at concentrations of 1, 2 and 4.0 µg/mL. The microorganism test used was Staphylococcus aureus ATCC 6538p, and Antibiotic Medium 3 was used as the culture medium. Method validation demonstrated that the bioassay was linear (r=0.9995), precise (RSD=2.58%), accurate (recovery 100.48± 2.11%), and robust. Degradation kinetics was also performed in an alkaline medium, indicating that daptomycin degradation follows first order kinetics under these conditions. The analyses of degraded solutions showed that daptomycin degradation products do not possess bactericidal activity. The bioassay was compared to HPLC method that was previously developed and no significant difference was found between them (p>0.05). The method proved to be appropriate for daptomycin injection quality control.

resumo A daptomicina (DPT) é o primeiro lipopeptídeo cíclico disponível para comercialização. Possui atividade frente a bactérias gram-positivas, incluindo cepas resistentes. O objetivo deste trabalho foi desenvolver e validar um ensaio microbiológico turbidimétrico para quantificar a daptomicina na forma injetável. Empregou-se delineamento 3x3, nas concentrações de 1,0; 2,0 e 4,0 µg/mL. Como micro-organismo teste foi usado Staphylococcus aureus ATCC 6538p, e Meio para Antibióticos nº 3 foi empregado como meio de cultura. A validação do método demonstrou que o ensaio foi linear (r=0,9995), preciso (RSD=2,55%), exato (recuperação de 100,48 ± 2,11%) e robusto. A cinética de degradação em meio alcalino foi avaliada, indicando que a daptomicina segue cinética de primeira ordem nessa condição. A análise das soluções degradadas mostrou que os produtos de degradação da daptomicina não possuem atividade antimicrobiana. O bioensaio foi comparado com o método por CLAE previamente desenvolvido e não houve diferença significativa entre ambos (p<0,05). O método mostrou-se apropriado para o controle de qualidade da daptomicina injetável.

A green approach for the quantification of daptomycin in pharmaceutical formulation by UV spectrophotometry

abstract Daptomycin is the first approved drug from a new class of antimicrobials, the cyclic lipopeptides, and is a very important antimicrobial agent in current clinical practice. Currently, there are no "green" analytical methods described in the literature to analyze the typical pharmaceutical dosage form of daptomycin. Thus, the aim of this work was to validate an environment-friendly spectrophotometric method in the UV region, for the analysis of daptomycin as a lyophilized powder. Water was used as diluent and the analyses were carried out on a spectrophotometer at 221 nm. The method met all validation requirements of the ICH guidelines, over a concentration range of 6-21 µg mL-1. A Student's t-test demonstrated that the proposed method was comparable to an HPLC method previously validated. Thus, the validated spectrophotometric method could quantify daptomycin in a powder form for injectable solutions, while being an economical, rapid, and "green" alternative for routine analysis in quality control.

resumo A daptomicina é o primeiro membro aprovado de uma nova classe de antimicrobianos, os lipopeptídeos cíclicos, e é muito importante para a prática clínica atualmente. Não existem métodos analíticos "verdes" descritos na literatura para a análise da daptomicina na forma farmacêutica. Desta forma, o objetivo deste trabalho foi a validação de método espectrofotométrico na região do UV ambientalmente favorável para análise da daptomicina em pó liofilizado. A água foi escolhida como diluente e as análises foram realizadas em 221 nm. O método atendeu a todas as exigências de validação dos guias do ICH, na faixa de 6-21 µg mL-1. Teste t de Student mostrou que o método proposto é intercambiável com método de HPLC previamente validado. Assim, o método espectrofotométrico validado é capaz de quantificar a daptomicina em pó para solução injetável e é uma opção econômica, rápida e "verde" para análises de rotina do controle de qualidade deste fármaco.