ABSTRACT
OBJECTIVES: Vancomycin therapeutic drug monitoring is challenging, especially in the paediatric population where evidence is scarce. The main objective of this study was to analyse the achievement of therapeutic concentrations of vancomycin in paediatric patients and to evaluate the current monitoring method (trough levels), doses used, and the time required to achieve target concentrations. METHODS: Paediatric patients on treatment and monitored with vancomycin from November 2019 to December 2021 were included. Those with only one determination of serum vancomycin concentration were excluded. Demographic variables, analytical and microbiological parameters and toxicity data were collected. Pharmacokinetic parameters were assessed at baseline and during treatment. RESULTS: 225 patients (40.9% female; 108 neonates, 49 infants and 68 children or adolescents) were included in the study. The main indications for vancomycin treatment were sepsis (33.9%) and fever of unknown origin (29.3%). Microbiological cultures were positive in 71.1%, mostly with Gram-positive bacteria (60.4%). Therapeutic levels of vancomycin were reached in only 20.1% of the participants in the first determination. After pharmacokinetic monitoring, 81.7% of patients reached therapeutic concentrations, requiring a 23% increase in the initial dose, a 2-day lag time and 1-2 dosage adjustments until the therapeutic concentration was reached. Of the total patients, 13 developed nephrotoxicity, nine neutropenia and one patient developed red man syndrome. CONCLUSIONS: In our sample of paediatric patients, the recommended doses of vancomycin were insufficient to achieve therapeutic concentrations. Revision of the recommendations and/or a change in the method of pharmacokinetic monitoring is crucial to optimise treatment in this population.
ABSTRACT
Presentamos el caso de una interacción farmacológica entre nirmatrelvir/ritonavir (fármaco aprobado para la infección por COVID-19) y voriconazol, derivada del efecto bidireccional del ritonavir sobre las 2 principales enzimas metabolizadoras del voriconazol (citocromo P450 3A y 2C19) de forma que, ritonavir inhibe la primera e induce la segunda.De acuerdo con las principales bases de datos de información farmacoterapéutica, en la interacción entre ambos fármacos, se espera una disminución en el área bajo la curva del voriconazol por el efecto inductor de su metabolismo, sin embargo, en el caso que presentamos ha ocurrido el efecto opuesto, se dan niveles supraterapéuticos de forma mantenida, lo cual es un efecto paradójico según la literatura.Dado el corto periodo de tratamiento con nirmatrelvir/ritonavir (5 días), no llega a manifestarse el efecto inductor del ritonavir propuesto en los estudios en los que se basan las recomendaciones, donde el tratamiento con ritonavir es más prolongado. (AU)
This case is based on a drug interaction between nirmatrelvir/ritonavir (approved drug for COVID-19) and voriconazole is presented, possibly derived from the bidirectional effect of ritonavir on the 2 main voriconazole metabolising enzymes (cytochrome P450 3A and 2C19) ritonavir inhibits the former and induces the latter respectively.According to the main pharmacotherapeutic information databases, in the interaction between both drugs, a decrease in the area under the curve of voriconazole is expected due to the.inducing effect of its metabolism; however, in the case we present, unexpectedly, a paradoxical effect occurs, according to what is described in literature, with the result of sustained supratherapeutic levels of voriconazole.Given the short treatment period with nirmatrelvir/ritonavir (5 days), the induction effect of ritonavir proposed in the studies on which the recommendations are based, where treatment with ritonavir is longer, does not occur. (AU)
Subject(s)
Humans , Ritonavir/therapeutic use , Voriconazole/therapeutic use , Severe acute respiratory syndrome-related coronavirus , Coronavirus Infections/epidemiology , Drug TherapyABSTRACT
This case is based on a drug interaction between nirmatrelvir/ritonavir (approved drug for COVID-19) and voriconazole is presented, possibly derived from the bidirectional effect of ritonavir on the 2 main voriconazole metabolizing enzymes (cytochrome P450 3A and 2C19) ritonavir inhibits the former and induces the latter respectively. According to the main pharmacotherapeutic information databases, in the interaction between both drugs, a decrease in the area under the curve of voriconazole is expected due to the inducing effect of its metabolism; however, in the case we present, unexpectedly, a paradoxical effect occurs, according to what is described in literature, with the result of sustained supratherapeutic levels of voriconazole. Given the short treatment period with nirmatrelvir/ritonavir (5â¯days), the induction effect of ritonavir proposed in the studies on which the recommendations are based, where treatment with ritonavir is longer, does not occur.
Subject(s)
COVID-19 , Ritonavir , Humans , Voriconazole/therapeutic use , Ritonavir/therapeutic use , COVID-19 Drug TreatmentABSTRACT
This case is based on a drug interaction between nirmatrelvir/ritonavir (approved drug for COVID-19) and voriconazole is presented, possibly derived from the bidirectional effect of ritonavir on the 2 main voriconazole metabolising enzymes (cytochrome P450 3A and 2C19) ritonavir inhibits the former and induces the latter respectively. According to the main pharmacotherapeutic information databases, in the interaction between both drugs, a decrease in the area under the curve of voriconazole is expected due to the. inducing effect of its metabolism; however, in the case we present, unexpectedly, a paradoxical effect occurs, according to what is described in literature, with the result of sustained supratherapeutic levels of voriconazole. Given the short treatment period with nirmatrelvir/ritonavir (5 days), the induction effect of ritonavir proposed in the studies on which the recommendations are based, where treatment with ritonavir is longer, does not occur.
