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.

OBJECTIVE

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.