ABSTRACT
Introducción: en México, la cuantificación de fármacos en plasma se utiliza para comprobar la toxicidad, el cumplimiento y la titulación de dosis en el tratamiento con fármacos anticonvulsivos como el ácido valproico (AVP), pero sin considerar los principios de farmacocinética debido a la ausencia de farmacéuticos clínicos en el Sistema de Salud. Método: el presente estudio es un análisis retrospectivo que incluye los datos de concentración plasmática de ácido valproico en pacientes pediátricos de 1 a 15 años de edad, con diagnóstico confiable de epilepsia. Resultados: se revisaron los archivos de 260 pacientes, se encontró que solo el 56,5% de los pacientes tenían niveles séricos en estado estacionario. Los niveles plasmáticos de AVP se encontraron a nivel subterapéutico en el 22% de los pacientes y el 15% tenían niveles tóxicos. El análisis muestra que los niños menores de cinco años aparecen como un grupo heterogéneo para las variables estudiadas. Conclusiones: debido a la falta de reconocimiento de los farmacéuticos clínicos en México, recomendamos que el mejor resultado clínico se evalúe mediante el monitoreo de los parámetros farmacocinéticos y no solo mediante la dosificación de prueba y error. (AU)
Introduction: in Mexico, plasma drug quantitation is used to check toxicity, compliance, and dose titration in treatment with antiepileptic drugs like valproic acid (AVP), but without considering the principles of pharmacokinetics due to the absence of clinical pharmacists into the Health System. Method: the present study is a retrospective analysis including the plasmatic concentration data of AVP in pediatric patients of 1 to 15 years old, who had received a reliable diagnosis of epilepsy. Results: files of 260 patients were reviewed. It was found that only 56,5% of the patients had serum levels at steady state. The plasma AVP levels were found in sub-therapeutic level in 22% of patients and 15% had toxic levels. The analysis shows that children under five years of age appear as a heterogeneous group for the variables studied. Conclusions: due to the lack of recognition of clinical pharmacists in Mexico, we recommend that best clinical outcome can be evaluated only by monitoring pharmacokinetic parameters for variations appearing in individual patients, and not just through trial and error dosing.
Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , 34628 , Valproic Acid , Pediatrics , MexicoABSTRACT
Vancomycin, a glycopeptide antibiotic, was developed-and released in the 1950's for the treatment of aerobic gram-positive infections and has been widely used mainly in the treatment of methicillin-resistant Staphylococcus aureus infections. Early reports regarding the possibility of nephrotoxicity and ototoxicity led to concern about the use of vancomycin and the need to monitor serum concentrations. In Mexico, the National Institute of Cardiology measures serum level of some drugs, such as vancomycin on a routine basis. Nevertheless, although a large number of measurements are made, the quantification of drug in serum is only used by physicians as a empiric parameter for dose adjustment. The aim of this work was to know whether dosing was appropriate taking the therapeutic interval as a commonly accepted baseline and to propose viable alternatives in the case dosing was inadequate. Peak and through vancomycin levels were analyzed retrospectively (n=295), in patients from 18 to 65 yr old with diagnosis of sepsis. The relationship between administered dose and measured blood levels was established. The equation that characterizes the study population was obtained based on a single compartment model considering the proportional relationship between vancomycin and creatinine clearance. The analysis shows that only 44% of C(trough) and 47% of C(peak) values represented therapeutic levels, with the remainder either toxic or ineffective.
Subject(s)
Drug Monitoring , Vancomycin/blood , Adolescent , Adult , Aged , Creatinine/blood , Humans , Middle Aged , Retrospective StudiesABSTRACT
Tacrolimus, a macrolide immunosuppressant agent, is indicated for the prophylaxis of organ rejection in patients receiving allogenic liver or kidney transplantation. Successful therapy is complicated by both intra- and inter-patient variability in drug absorption, coupled with the drug's narrow therapeutic index. Moreover, clearance, is significantly affected by co-administration with food and with additional factors such as length of posttransplantation time. At the National Institute of Cardiology, Mexico, the measure of tacrolimus levels is carried out as a common analysis on patients who have been transplanted as a measure to make empiric doseage adjustments. The purpose of this study was to investigate whether tacrolimus levels exceed the desired therapeutic range in adult patients being initiated on a dosage regimen and to establish the use of pharmacokinetic concepts to avoid organ rejection and other complications related to tacrolimus over-exposure. The patients were followed from 1 week to 6 months after transplantation and a mean of 12 samples were collected (11.92 +/- 2.59 ng/mL) from each patient. Modeling was used to establish the correlation between the doses administered per kilogram of body weight, the tacrolimus level measured and the post-transplantation time. Of 155 tacrolimus measurements, only 48.4% were found within the therapeutic range (5-10 ng/mL); 7.1% below and 44.5% with elevated levels. Tacrolimus has proven its usefulness in solid organ transplants, but this study demonstrates that it is essential to carry out close monitoring through the application of pharmacokinetic concepts to optimize therapy.
