RESUMEN
Infections are a common problem in dialysis patients. As hospital stay shortens, many require outpatient antibiotic therapy. Parenteral administration may pose considerable logistic and financial burdens, whereas daily intraperitoneal dosing increases the risk of contamination. Ceftazidime, with its long half-life, may provide adequate dosing when administered intraperitoneally thrice weekly. The authors therefore studied the kinetics of a 2 g loading dose followed by a 1.5 g dose every 48 hr in seven stable chronic peritoneal dialysis patients. In vitro stability at 4 degrees C (measured by high performance liquid chromatography) was 91% at 120 hr. Peak serum concentration (60 +/- 22 microg/ml) was reached at 4.9 +/- 2.2 hr. Serum values were 25 +/- 9 and 8 +/- 3 microg/ml at 24 and 48 hr, respectively. However, median trough levels at 48 hr in dialysate were significantly lower than in serum (2.8 vs 8.5 microg/ml, respectively; p = 0.0425). Pharmacokinetic parameters were as follows: bioavailability (F), 88% +/- 8%; volume of distribution at steady state (VDss), 20 +/- 8 L; absorption half-life (T1/2(abs)), 1.8 +/- 1.3 hr; elimination half-life (T1/2(el)), 11.4 +/- 4.5 hr; and clearance (CL), 22 +/- 10 ml/min. Intraperitoneal ceftazidime every 48 hr is a practical alternative to parenteral therapy of nonperitoneal infections. In peritonitis, whether increased permeability results in improved dialysate levels remains to be defined.
Asunto(s)
Ceftazidima/farmacocinética , Cefalosporinas/farmacocinética , Fallo Renal Crónico/tratamiento farmacológico , Esquema de Medicación , Humanos , Infusiones ParenteralesRESUMEN
Heparin is widely used in current practice for a variety of indications. It is well known that it can cause thrombocytopenia, but not that thrombosis may also develop in thrombocytopenic patients and cause significant morbidity and mortality. A 56-year-old woman developed heparin-induced thrombocytopenia with thrombosis that resulted in the amputation of her leg. It is proposed that the reaction has an immune-mediated mechanism. Several ways of diagnosing the condition are available, specifically the serotonin-release assay and an enzyme-linked immunosorbent assay. The investigational agent danaproid may be effective in the treatment of heparin-induced thrombocytopenia with thrombosis.
Asunto(s)
Anticoagulantes/efectos adversos , Heparina/efectos adversos , Trombocitopenia/inducido químicamente , Trombosis/inducido químicamente , Femenino , Humanos , Persona de Mediana Edad , Trombosis/complicacionesRESUMEN
This study documented the formaldehyde exposures of a group of veterinary medicine students. It also investigated the feasibility of biologically monitoring the exposures. The biological monitoring was based on the fact that the formaldehyde is metabolized in the body to formic acid, and may then be excreted in the urine. Therefore, exposures to formaldehyde could theoretically create a shift in the formic acid levels in the urine. Normal baseline levels of urinary formic acid were first established for each subject. The baselines of most students were quite variable. Very few exhibited a "tight variability" in their baseline. Next, three sets of pre- and post-exposure urine samples were taken. A series of paired t-tests were run on these "pre" and "post" sets. The results indicated that no significant formic acid shift was seen. A subset of the samples was "corrected" for specific gravity. However, this adjustment did not have an effect upon the relative formic acid levels. In addition, no significant formic acid shift was seen in the adjusted group. Exposure levels of the students were less than 0.5 ppm of formaldehyde. Therefore, the main conclusion of the study was that biological monitoring of formaldehyde exposures (via formic acid shifts) at these low levels was not a feasible technique.