Background: Paracetamol (APAP) is the most famous drug used in the world to relieve of
pain and used as an antipyretic. Paracetamol overdose induces liver damage and is a well
known hepatotoxic drug. This study was aimed to determine the incidence of acidosis in
acetaminophen overdose with the time of N- Acetyl Cystiene (NAC) administration and
correlation of late acidosis and death in acetaminophen overdose. Materials and methods:
The data were obtained from the patients' files admitted to AL-Noor Hospital due to the
ingestion of Paracetamol overdose. The Data on Paracetamol levels, liver transaminases
(AST, and ALT), arterial blood gases, lactate levels and serum electrolyte levels had been
collected from files. Results: Fifty five cases were divided into three groups: Group I (33
cases) had early acidosis with toxic APAP dose; Group II (9 cases) had late acidosis with
toxic APAP dose; and Group III (13 cases) with non toxic APAP ingestion or developed
acidosis. In 65.45% of cases, the age was between 14-30 years. Most of the cases were
females (74.5%), and the adult was 78.77% while 21.23% were children. There was a
positive significant relation (P < 0 .05) Between APAP toxic doses, early NAC
administration, early anion gap acidosis and complete recovery. Also, there was a positive
significant relation (P < 0.05) between, APAP toxic doses, late NAC administration, late
lactic acidosis with coma and death. There was no significant relation (P > 0.05) between
serum transaminases and toxic APAP level or prognosis. Conclusion: Metabolic acidosis are
a specific indicator for APAP heptotoxicity than serum transaminases
KEY WORDS: Paracetamol overdose, Metabolic acidosis, APAP hepatotoxicity