role of n - acetylcystein ( nac ) in adults with non - acetaminophen induced liver failure was described in few studies in literature . studies were particularly relevant to countries where , liver transplantation facilities are limited or unavailable . found a significantly improved transplantation free survival at 3 weeks and at 1 year with the use of nac in non - acetaminophen related liver failure , the benefit being confined to those with early hepatic encephalopathy . dengue infection is prevalent in southeast asia , and according to the epidemiological unit , ministry of health , sri lanka , during the last 4 months of the year 2012 , 11148 suspected dengue cases and 46 deaths have been reported . the elevation of transaminases is usually less than five - fold greater than upper limit of normal . however , levels more than five - fold were reported 36.8% and 74.4% of patients with classical dengue and dengue hemorrhagic fever ( dhf ) respectively . fulminant hepatitis tends to occur more often in dhf or dengue shock syndrome compared to classic dengue infection and case fatality rate of 50% being reported . although , nac has shown benefit in non - acetaminophen related liver failure , it was not well studied in dengue associated severe hepatitis . a previously healthy 54-year - old mother of three admitted with 3 day history of fever , headache and body ache . physical examination on investigation on the day of admission revealed platelets 84,000/cumm and haematocrit ( hct ) 37% . on the 2 day , she was transferred to intensive care unit ( icu ) as her platelets dropped to 41,000 per cu mm and hct increased to 47% . liver transaminases showed mild to moderate rise with ( ( ast ) aspartate transferase ) 302 u / l and ( ( alt)alanine transferase ) 262 u / l and patient was given total dose of 10 g of acetaminophen over 3 days at the time . she had stable hemodynamics apart from heart rate of 121 beats / min , but she developed right side moderate pleural effusion , icterus , mild ascites and right hypochondrial pain . in the icu , she deteriorated further , with a decline of glasgow coma scale ( gcs ) to 11 , but no focal neurological signs . urgent computed tomography brain was done and it neither showed intracranial hemorrhage nor evidence of increased intracranial pressure . her liver functions continued to deteriorate and liver enzymes reached peak value of ast 16261 u / l and alt 4545 u / l , ( pt / inr ) prothrombin time / international normalized ratio 1.7 and total bilirubin 5.9 mg / dl on 4 day of admission ( 7 day of illness ) . intravenous nac was started at 100 mg / kg / day as an infusion and continued for 5 days with liver failure regime . marked improvement in liver enzyme was noted and sgot and sgpt levels dropped by more than half by 48 h of treatment . on the 9 day of admission , liver function revealed ast 300 u / l , alt 223 u / l and pt / inr 1.2 , and her conscious level improved to gcs of 15 . during the course of illness , she had mild gum bleeding and few ecchymotic patches with lowest platelet count of 18,000 per cu mm . her serology was positive for dengue antibodies but negative for hepatitis a and b. hepatitis e serology was not done due to unavailability . co - infection of malaria was not excluded as she was from neither endemic area nor her symptomatology typical of malaria including fever pattern . possibility of leptospirosis can not be excluded in this case as serology was not done . however , she did not have any exposure and her renal functions were never abnormal . during her follow - up visit at 2 weeks after discharge , she had normal liver profile and did not have any evidence of chronic liver disease . both virus itself and dysregulated immune response to virus are being described as possible mechanisms of liver damage in literature . although , severe hepatitis associated with dengue fever is a rare occurrence , it carries significant mortality and morbidity . nac , mostly used in acetaminophen poisoning , acts through its antidote effect of repletion of hepatocellular glutathione stores . nac scavenges free radicals , improves antioxidant defense and acts as a vasodilator to improve oxygen delivery and consumption . these properties of nac have been postulated to improve outcome in patient with dengue associated acute liver dysfunction . concluded that benefit is seen when nac is used early stage of liver failure rather than late stage . a retrospective analysis on nac in dengue associated liver failure by kumarasena et al . showed that 5 patients who survived out of 8 were in early ( coma grade 1 , 11 ) liver failure stage at the time when nac was started . this case report also supports the view that intravenous administration of nac is safe and benefits patients , if started in early stage of liver failure . this patient was treated with intravenous nac 100 mg / kg / day infusion for 5 days compared to 150 mg / kg bolus over 15 min followed by 12.5 mg / kg / h for 4 h and then 6.25 mg / kg / h for 72 h was given by kumarasena et al . in their retrospective analysis . reported a pediatric patient with dengue associated liver failure successfully treated with nac and they have given intravenous nac 100 mg / kg / day for 6 days . large randomized trials should be carried out to establish its efficacy along with appropriate dosage , timing , and duration of treatment .
although , n - acetylcystein ( nac ) has shown benefit in non - acetaminophen related liver failure , it was not well studies in dengue associated severe hepatitis . 
 we report a case of dengue hemorrhagic fever associated severe hepatitis ( encephalopathy grade 2-drowsy and intermittent disorientation ) treated with nac resulted in good outcome without hepatic transplantation .