Document Type : Original Article

Authors

• Babak Mostafazadeh ¹
• Soheila Vaghefi ²
• Mohammadali Emamhadi ³
• Latif Gachkar ⁴

¹ Associate Professor, Department of Forensic Medicine and Toxicology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

² Clinical Specialist in Forensic Medicine and Toxicology, Mofid Educational Hospital, Department of Forensic Medicine and Toxicology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran

³ Associate Professor of Forensic Medicine and Toxicology, Department of Forensic Medicine and Toxicology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran

⁴ Professor of Infectious Diseases, School of Medicine, Department of Infectious Diseases, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Abstract

Background: Acetaminophen (N-Acetyl-p aminophenol; APAP) is one of the most common types of analgesics. It is also the most common xneobitic reported to poison centers. This study investigates if therapeutic doses of NAC can falsely increase coagulation tests, prothrombin time (PT) and bleeding time (BT). ​​
Methods: Thirty-six APAP poisoned patients whose acetaminophen serum concentration were in toxic zone in the Rummak-Matheiw graph were treated by NAC according to standard intravenous 21 hours protocol.  Prothrombin time (PT) and bleeding time (BT) in all cases were measured before the start of the NAC and at the 8^th and 16^th hour of the treatment.
Results: The mean age of the cases was 21.5 ± 5.12 years old. Among them, 31 cases (86%) were female. The mean dose of ingested APAP was 9.6 ±2.0 grams (7.8 – 16.1 g). Mean of SLA was 196.0±37.7. The means of BT were nor significantly different at all evolution times (2.6±0.64, 2.6±0.62 and 2.6± 0.6. The means of PT rose at 16^th hour of NAC treatment in as compared 8^th hour (16.1± 1.1 s 12.3±0.6 s, respectively) (P <0.001).   
Conclusion: With specific reference to our study results, a low level of rising PT resulting from an NAC treatment is not a reliable indicator of liver damage. Further investigation on the effect of NAC on clotting factors is recommended.

Highlights

Mostafazadeh B, Vaghefi S, Emamhadi M, Gachkar L. Evaluation of Prothrombin Time in Acute Acetaminophen Overdose treated by N-acetylcysteine. Asia Pac J Med Toxicol 2016;2:42-4

Keywords

• Acetaminophen Poisoning
• N-acetylcysteine
• Bleeding Time
• Prothrombin Time