Elevated transaminases are found in both rhabdomyolysis and delayed acetaminophen (APAP) toxicity. Establishing the cause of elevated transaminase can be difficult when there is unclear history of acetaminophen ingestion.

A retrospective study of patients with delayed acetaminophen toxicity or rhabdomyolysis from 2006 to 2011 was recently published.

The authors compared AST/ALT, CK/AST and CK/ALT ratio of 

• 160 in the rhabdomyolysis group
• 68 in the acetaminophen overdose (all)
• 29 in the delayed acetaminophen overdose group

Results

AST/ALT ratio

• Rhabdomyolysis group: 1.66
• APAP overdose (all): 1.38
• Delayed APAP overdose: 1.3

CK/AST ratio

• Rhabdomyolysis group: 21.3
• APAP overdose (all): 5.49
• Delayed APAP overdose: 3.8

CK/ALT ratio

• Rhabdomyolysis group: 37.1
• APAP overdose (all): 5.77
• Delayed APAP overdose: 5.03

Conclusion

• Significantly higher ratio of AST/ALT, CK/AST and CK/ALT were found in rhabdomyolysis patients than delayed APAP overdose patients.
• These finding are based on small study population and need further validation/research before clinical application.