Hy's Law (used by Temple in reference to Hyman Zimmerman) can help to identify a drug with serious hepatotoxicity, ideally prior to regulatory approval.
Criteria for Hy's law:
(1) The patient is exposed to a drug that can cause hepatocellular injury (at rates in excess of any hepatotoxicity seen in controls).
(2) The total serum bilirubin is >= 2 times the upper limit of normal. Usually the patient is jaundiced but jaundice may be difficult to detect clinically.
(3) The serum transaminases (AST, ALT) are >= 3 times the upper limit of normal. The levels often are much higher.
(4) Exclusion of other explanations (cholestasis from intrahepatic or extrahepatic obstruction, Gilbert's syndrome, etc).
A patient who meets these criteria is at risk for serious hepatotoxicity with a 10-15% risk of death or liver transplant.
The underlying premise is that any hepatotoxic damage that is severe enough to interfere with bilirubin metabolism and excretion is significant.
Performance:
• The law can help to identify a drug that can be a serious threat. However, a drug may not meet the criteria and yet still be a significant hepatotoxin.
To read more or access our algorithms and calculators, please log in or register.
