The Expert: Dr. Charles McKay, an emergency medicine and toxicology expert in Connecticut, outlines his belief that acetaminophen did not cause the plaintiff’s liver injury.
During a 2015 product liability trial, an emergency medicine physician with special certification in medical toxicology, Dr. Charles McKay, presents evidence involving acetaminophen overdose to support his belief that Extra Strength Tylenol caused a patient’s liver damage, as she claimed.
McKay begins by presenting the typical graph patterns for the liver enzymes ALT and AST as serially measured in the bloodstream over time after liver damage has occurred from regular acetaminophen exposure. In this way, he shows that the damage pattern in this patient was the same as that seen after such exposure. Taking this same approach with the measurement of prothrombin time (a measure of clotting ability) after conversion to INR (International Normalized Ratio), which standardizes the performance of blood clotting tests, the expert points out that not only did the INR, a measure of liver function, become abnormal after exposure, but it returned to normal over time in a pattern expected with damage caused by acetaminophen. These patterns are indicative of a liver that has been damaged and is recovering. He would expect the recovery to continue.
The doctor’s charts also demonstrated that acetylcysteine, a drug given for treatment of acetaminophen overdose, was given during the recovery phase and had no influence on the outcome in this case.
The medical toxicologist informs the jury that these patterns are reliably reproducible and indicative that the patient had been exposed to the offending agent about three days prior to these findings. He concludes that the patient ingested an overdose of acetaminophen at that time.
The Poison Control Center had been contacted regarding this case. The intake form from that contact is displayed. This form indicated that there was an “acute on chronic” exposure during an unknown timeframe of “intentional misuse of acetaminophen” as reported to the PCC by a nursing supervisor at the hospital on the third hospital day. This report says specifically that the patient had been taking regular strength acetaminophen as opposed to extra strength Tylenol. There was no indication anywhere in the medical records that the extra strength form of this medication was taken.
The jury was convinced by this testimony that the Extra Strength Tylenol pain reliever was not responsible for the liver injuries which the patient sustained.
Gary Gansar, MD, is residency-trained in general surgery. He served as Chief of Surgery and Staff at Elmwood Medical Center and on the Medical Executive Committee at Touro Infirmary and Mercy Hospital in New Orleans, LA. Dr. Gansar was Board Certified in general surgery while in active practice. He joined AMFS in 2015 as a Physician Medical Director.
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