[Effect of smoking on caffeine elimination by the liver in patients with chronic liver diseases].

Effect of smoking cigarettes on hepatic metabolizing capacity of caffeine in respect to the extent of liver damage was studied among 46 patients with chronic liver disease and 6 healthy, nonsmoking subjects. The rates of hepatic elimination in cirrhosis (68 +/- 35 ml/min) and chronic extrahepatic cholestasis (60 +/- 32 ml/min) were lower in comparison to steatosis (132 +/- 38 ml/min), chronic active hepatitis (115 +/- 35 ml/min) and healthy control group (115 +/- 46 ml/min). Generally, the patients smoking cigarettes (n = 21) metabolized caffeine more rapidly than nonsmoking patients (107 +/- 42 ml/min vs 71 +/- 41 ml/min, p less than 0.01). In cirrhotics we observed the 9% difference of caffeine clearance between smokers and non-smokers, whereas in ++ groups of patients showing no significant impairment of caffeine elimination rate (steatosis, hepatitis) the tobacco induced the 33% change in caffeine clearance. Healthy nonsmoking subjects metabolized caffeine more rapidly than smoking cirrhotics (115 +/- 46 ml/min vs 71 +/- 26 ml/min, p less than 0.05). It may be concluded that smoking cigarettes increase hepatic elimination rate of caffeine in chronic liver disease, however the range of this effect depends upon the extent of liver damage.