Evolución clínica de pacientes chilenos con tirosinemia tipo I tratados con 2-(2-nitro-4-trifluorometilbenzoil)-1,3-ciclohexanediona (NTBC) / Clinical follow up of Chilean patients with tyrosinemia type 1 treated with 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-ciclohexanedione (NTBC)

Background: Tyrosinemia type I is an inborn error of metabolism due to deficiency of fumarilacetoacetase. Acute presentation is with liver failure, hypophosphatemic rickets and peripheral neuropathy. Chronic presentation is with visceromegaly and subclinical rickets. The most severe complications are hepatic cancer and acute neurological crises. Without treatment, tyrosinemia type 1 is fatal. In 1992 treatment for tyrosinemia type 1 with 2-(2-nitro-4-trifluoromethybenzoyl)-1,3-ciclohexanedione (NTBC) was proposed. A clinical response was reported in 90% of patients. In cases that did not respond, a successful liver transplantation was performed, reducing mortality to 5%. Aim: To report the follow up of 12 patients treated with NTBC. Patients and Methods: Review of clinical records of 12 Chilean cases treated with NTBC at the Instituto de Nutrición y Tecnología de los Alimentos (INTA) from January 2004 until June 2010. Results: In all patients, a rapid metabolic control was achieved. Two patients developed hepatocarcinoma. One of these patients died and one was successfully treated with liver transplantation. One patient died after receiving a liver transplantation. Nine patients have at present good liver function, but 2 had peripheral neuropathy due to late diagnosis and discontinuing NTBC treatment. Conclusions: Treatment with NTBC allows metabolic normalization in tyrosinemia type 1, prevents liver cirrhosis and hepatic cancer, improving survival rates and quality of life in the patients. Neonatal screening is essential for the early diagnosis of this treatable disease, that otherwise may be lethal.

Antagonismo de los efectos disociados de la Ketamina con Naloxona / Antagonism of the dissociative ketamine effects with naloxone

Se estudia la acción de la naloxona sobre los efectos disociativos de la ketamina, con el objeto de poder establecer la participación del sistema opioide endógeno en la génesis de dichos efectos, para lo cual se estudiaron 30 pacientes adultos del sexo femenino, siguiendo un procedimiento simple ciego y dos paradigmas farmacológicos diferentes con cuatro condiciones consecutivas cada uno: 1. Control inicial (C), ketamina (K), solución salina isotónica (S) y control final (C'). 2. C, K, naloxona (N) y C'. La naloxona disminuyó significativamente el tiempo de recuperación y nistagmus, y antagonizó la analgesia y efectos cardiovasculares de la ketamina. Se concluye que los efectos de la ketamina son medidos en gran parte por el sistema opiode endógeno, ya que dosis bajas de un antagonista específico revierte significativamente tales efectos.