[Carboxypeptidase-G2 administration after high-dose methotrexate. Treatment and drug interactions]. / Administración de carboxipeptidasa tras altas dosis de metotrexato. Tratamiento e interacciones medicamentosas.

Methotrexate (MTX) is widely used as anticancer agent in various malignancies, including acute lymphoblastic leukaemia, lymphoma and osteosarcoma. High doses of MTX may cause acute renal dysfunction. Nephrotoxicity is prevented by the use of alkalinization and hydration. More recently Carboxypeptidase-G2, a recombinant bacterial enzyme that rapidly hydrolyzes MTX to inactive metabolites, has become available for the treatment of acute nephrotoxicity. On the other hand, glutamine is usually administered in oncology treatments to avoid other side effects. We report a case of an adolescent who was diagnosed with T lymphoblastic lymphoma. He was receiving treatment with glutamine when the third course of methotrexate was administered (5 g/m(2)) and he suffered a deterioration in his renal function. Carboxypeptidase was used but the methotrexate serum concentration reduction was not satisfactory. The technique to assess the amount of enzyme-inactivated methotrexate by quantification of MTX metabolites is not available in our country, therefore, the concentrations of MTX may be overestimated. The literature was reviewed to study the influence of glutamine on delayed methotrexate elimination which may lead to acute toxicity.

[Adequacy of acute peritoneal dialysis in pediatric patients]. / Adecuación de diálisis peritoneal aguda en Unidad de Cuidados Intensivos Pediátrica.

Acute peritoneal dialysis (APD) is still a useful tool in the critical pediatric patient. Acute kidney failure due to septic shock often requires invasive depuration procedures and although hemofiltration is very effective, not all pediatric Intensive Care Units have the equipment necessary to establish it. Pediatric APD is generally initiated with short dwell times, every hour exchanges and 10-20 ml/kg filling volumes. We present the evolution of two critical patients with kidney failure on APD who benefited from the measurement of dialysate-to-plasma (D/P) ratios for creatinine and urea, and dialysate-to-solution ratio for glucose (Dt/Do) to optimize APD prescription.