The impact of current tobacco use on the outcome of paracetamol poisoning

BACKGROUND: Tobacco smoke contains a number of substances that are capable of inducing cytochrome P450. Consequently, current tobacco use may enhance the hepatotoxicity from a paracetamol overdose by increasing the oxidative metabolism of paracetamol.

AIM: To evaluate, by multivariate analysis, the effect of current tobacco use on the morbidity and mortality from paracetamol-induced hepatotoxicity.

METHODS: A retrospective study was carried out on the basis of the hospital charts of 602 patients admitted with single-dose paracetamol poisoning for whom information on current tobacco use was available.

RESULTS: In patients admitted with paracetamol poisoning, the rate of current daily tobacco use of 70% (424 of 602 patients) was considerably higher than the rate of 31% in the background population (chi-squared test: P < 0.0001). Current tobacco use was an independent risk factor for the development of hepatic encephalopathy (odds ratio, 2.68; 95% confidence interval, 1.28-5.62) and mortality (odds ratio, 3.64; 95% confidence interval, 1.23-10.75). Current tobacco use was independently associated with high peak values of alanine transaminase and the international normalized ratio.

CONCLUSIONS: Current tobacco use was very frequent in patients admitted with paracetamol poisoning. It was an independent risk factor of severe hepatotoxicity, acute liver failure and death following paracetamol overdose.