A Case of Psychosis and Elevated AST and ALT

Case

A 22-year-old male with a past medical history of anxiety and depression presents with acute psychosis after ingesting 3.5 grams of marijuana. He takes vortioxetine at home. On presentation, he was found agitated, throwing himself against walls.  AST and ALT were 187 U/L and 44 U/L on admission. Five days later, AST and ALT increased to 1,402 U/L and 402 U/L. All other liver chemistry tests, hemoglobin, white blood cell count, and INR are normal.

What is the most likely cause of his abnormal liver chemistry tests?

Correct Answer:

Rhabdomyolysis

While the other options are possible, rhabdomyolysis is the most likely answer in the differential given the pattern of liver enzyme elevation and clinical history. The self-harm experienced by the patient caused skeletal muscle necrosis, which is reflected in the liver chemistries: an aspartate aminotransferase: alanine aminotransferase (AST:ALT) ratio >3. This diagnosis was confirmed by an elevated creatine kinase (CK) level. Keep reading to learn how rhabdomyolysis causes certain liver chemistry abnormalities and how to differentiate this disease from the others listed.

Diagnosis of rhabdomyolysis and liver-related sequelae

Back to the case

In this case, creatinine kinase was elevated on admission to 83,000 U/L indicating skeletal muscle injury.

Back to the case

In order to definitively diagnose or exclude a case of drug-induced liver injury from either vortioxetine or marijuana, a thorough workup for intrinsic causes of liver disease and a liver biopsy would be needed.

Given the significant elevation in CK, rhabdomyolysis is the most likely cause of abnormal liver enzymes.

Natural history of liver-related sequelae

Treatment of rhabdomyolysis entails aggressive fluid resuscitation. The AST and ALT should improve as the CK improves and the muscle injury resolves. It is important to remember that AST has a shorter half-life (~17 hours) than ALT (~47 hours)—because of this difference, the AST levels improve faster than the ALT levels (Figure 1), and the AST:ALT ratio will change as the patient's disease course improves.

Figure 1: Changes in AST and ALT levels after their peak in a case series of muscle injury patients.

ALT: alanine aminotransferase; AST: aspartate aminotransferase. Taken from: Nathwani, R, et al. Serum Alanine Aminotransferase in Skeletal Muscle Diseases.Hepatology 2005. 41(2): 380-382.

One study showed that AST values, but not ALT values, decreased correspondingly with CK values in the first six days of hospitalization for rhabdomyolysis (Figure 2).

Figure 2: Decreases in AST mirror decreases in CK as rhabdomyolysis is treated.

Triangles are ALT values, squares are AST values, and diamonds are CK values. CK: creatine kinase; ALT: alanine aminotransferase; AST: aspartate aminotransferase. Taken from: Weibrecht, K, et al. Liver Aminotransferases are Elevated with Rhabdomyolysis in the Absence of Significant Liver Injury. J Med Toxicol 2010. 6:294-300.

  • Another important point to keep in mind: The transaminase increase is not a result of liver injury, but rather skeletal muscle injury.
  • As the patient continues to improve, serial liver chemistry tests should be performed to ensure improvement in the AST and ALT values. Liver chemistry tests should be checked after resolution of the rhabdomyolysis to document normalization of the AST and ALT values.