Can diabetes mellitus modify the plasma concentrations of rifampicin in patients under treatment for tuberculosis?

Abstract Rifampicin is a key component of treatment for tuberculosis and its efficacy is determined by the blood levels attained after therapeutic doses. However, there is a high variability of rifampicin blood levels that is related to both the patient and the formulation used. To date, the effect of diabetes mellitus on the plasma levels of rifampicin was low exploited, which could be relevant either by the significant increase of the comorbidity worldwide as by the probable influence of diabetes on the rifampicin exposure. The study aims to evaluate whether diabetes mellitus contribute to the variation of the maximum concentration of rifampicin in patients with tuberculosis treated with a daily dose of 10 mg/kg. Rifampicin and glycated hemoglobin were measured by high-performance liquid chromatography, and blood glucose by spectrophotometry. A total of 62 male patients were included in the study, and 26 presented diabetes mellitus. Rifampicin plasma levels in 2-h plasma samples collected at day 61 ranged from 3 µg/mL to 14.2 µg/mL. Drugs levels were similar between diabetic and non-diabetic patients and were not correlated with blood glucose and glycated hemoglobin. Moreover, a high percentage of patients in both groups presented low levels of rifampicin.

Concentrations of rifampicin in pre-dose samples in patients with pulmonary tuberculosis

ABSTRACT Rifampicin is used in both phases of treatment for tuberculosis. In chronic use, the short half-life and the self-induction of metabolism can decrease the levels of the drug below the minimal inhibitory concentration. The aim of the study was to investigate whether plasma concentrations of rifampicin are sustained above 0.5 µg/mL in patients with tuberculosis using 600 mg/day. Rifampicin was measured in plasma by high-performance liquid chromatography and a sputum smear microscopy was performed in all days of the study. A total of 44 male patients completed the study. On days 31, 61 and 91, the mean plasma concentrations of rifampicin were 0.6 (0.5) µg/mL, 0.55 (0.5) µg/mL and 0.46 (0.4) µg/mL. There was a high variation of rifampicin levels leading to a high percentage of samples with concentrations below 0.5 µg/mL. There was no significant association between the frequency of samples with drug levels below 0.5 µg/mL with the conversion of the sputum microscopy. These data suggest that pre-doses samples offer limited information on the exposure of M. tuberculosis to rifampicin.

Tendências de prescrição de antimicrobianos em idosos hospitalizados em um hospital universitário / Prescriptions of antimicrobial drugs for elderly people hospitalized in a universit y hospital

Este estudo teve como objetivo identificar tendências na prescrição de antimicrobianos em idosos hospitalizados em um hospital universitário no Estado do Pará. Estudo observacional e transversal que avaliou e analisou prontuários em relação a características do paciente, diagnóstico e tratamento, sendo tendências de prescrição identificadas por análise de frequência. Foram avaliados 299 prontuários, sendo observada uma predominância de idosos jovens (80%), do sexo feminino (56,5%), que tiveram como principal causa de internação infecções do trato respiratório. O tratamento foi predominantemente empírico, predominando a utilização de cefalosporinas de 3ª geração, macrolídeos e quinolonas. Quando relacionada a patologia ao medicamento predominou a utilização de cefalosporinas para o tratamento de infecções do trato respiratório e complicações da diabetes mellitustipo II. Identificou-se a necessidade de desenvolvimento de protocolos clínicos na instituição para padronização do tratamento e estímulo ao uso racional de antimicrobianos com o objetivo de garantir a segurança do paciente.

Trends in antimicrobial prescription for hospitalized elderly people in a university hospital in the state of Pará, Brazil, are identified. The transversal study evaluated and analyzed clinical cards on patients´ characteristics, diagnosis and treatments. Prescription trends are identified by the analysis of frequency. Further, 299 clinical cards were evaluated with a predominance of young female (56.5%) elderly people (80%), with infections of the respiration tract as the main cause of hospitalization. The predominantly empiric treatment comprised third generation cephalosporins, macrolides and quinolones. When pathology is related to medicine, the use of cephalosporins prevailed in the treatment of infections of the respiratory tract, with complications caused by Type 2 diabetes mellitus. The development of clinical protocols is required for the standardization of treatments and to stimulate the rational use of antimicrobial drugs to warrant the patient´s safety.