Tobacco smoke contains several substances capable of inducing cytochrome P450.
Therefore, tobacco use may enhance the hepatotoxicity from an acetaminophen overdose by increasing the oxidative metabolism of acetaminophen.
In this study, doctors from Denmark evaluated the effect of current tobacco use on the morbidity and mortality from acetaminophen-induced hepatotoxicity.
They performed a retrospective study which included 602 patients admitted with single-dose acetaminophen poisoning. Information on these patients' current tobacco use was available.
The doctors found that the rate of current daily tobacco use in patients admitted with acetaminophen poisoning was 70%, compared with 31% in the general population.
|Tobacco use was a risk factor for the development of hepatic encephalopathy.|
|Alimentary Pharmacology and Therapeutics|
They determined that current tobacco use was an independent risk factor for the development of hepatic encephalopathy (OR 2.68) and mortality (OR 3.64).
In addition, current tobacco use was independently associated with high peak values of alanine transaminase and the international normalized ratio.
Drs Schmidt and Dalhoff concluded, "Current tobacco use was very frequent in patients admitted with acetaminophen poisoning".
"It was an independent risk factor of severe hepatotoxicity, acute liver failure and death following acetaminophen overdose".