Colistin Use in Patients with Chronic Kidney Disease: Are We Underdosing Patients?

Colistin is administered as its inactive prodrug colistimethate (CMS). Selection of an individualized CMS dose for each patient is difficult due to its narrow therapeutic window, especially in patients with chronic kidney disease (CKD). Our aim was to analyze CMS use in patients with CKD. Secondary objectives were to assess the safety and efficacy of CMS in this special population. In this prospective observational cohort study of CMS-treated CKD patients, CKD was defined as the presence of a glomerular filtration rate (GFR) < 60 mL/min/m² for more than 3 months. The administered doses of CMS were compared with those recently published in the literature. Worsened CKD at the end of treatment (EOT) was evaluated with the RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease) criteria. Colistin plasma concentrations (Css) were measured using high-performance liquid chromatography. Fifty-nine patients were included. Thirty-six (61.2%) were male. The median age was 76 (45⁻95) years and baseline GFR was 36.6 ± 13.6. The daily mean CMS dosage used was compared with recently recommended doses (3.36 vs. 6.07; p < 0.001). Mean Css was 0.9 (0.2⁻2.9) mg/L, and Css was <2 mg/L in 50 patients (83.3%). Clinical cure was achieved in 43 (72.9%) patients. Worsened renal function at EOT was present in 20 (33.9%) patients and was reversible in 10 (52.6%). The CMS dosages used in this cohort were almost half those currently recommended. The mean achieved Css were under the recommended target of 2 mg/dL. Despite this, clinical cure rate was high. In this patient cohort, the incidence of nephrotoxicity was similar to those found in other recent studies performed in the general population and was reversible in 52.6%. These results suggest that CMS is safe and effective in patients with CKD and may encourage physicians to adjust dosage regimens to recent recommendations in order to optimize CMS treatments.

[Utility of infliximab therapy in severe enterorrhagia associated with Crohn's disease. Report of three cases]. / Utilidad del tratamiento con infliximab en la enterorragia severa asociada a la enfermedad de Crohn. Experiencia de tres casos.

Severe lower gastrointestinal (GI) bleeding is an infrequent complication in Crohn's disease. We report the cases of three patients with Crohn's disease, localized in distinct areas, who developed severe enterorrhagia requiring multiple transfusions. All three patients responded favorably to infliximab administration, which resolved the life-threatening hemorrhages and avoided emergency surgical resection, which had seemed inevitable. Based on this clinical experience and a review of the literature comparing infliximab with other pharmacological options, we believe that this drug should be the treatment of choice in patients with Crohn's disease who develop severe lower gastrointestinal bleeding. This strategy can, in some cases, avoid surgery if the bleeding stops due to rapid healing of the deep mucosal lesions causing the hemorrhagic episode.