1. Serum and salivary concentrations of caffeine (1,3,7‐ trimethylxanthine) and its dimethylxanthine metabolites were measured in 10 healthy control subjects and in 19 patients with cirrhosis, for up to 96 h following a 400 mg oral caffeine load. 2. Serum and salivary caffeine concentrations correlated significantly (r = 0.954; P less than 0.001) and no significant differences were observed in the pharmacokinetic data derived from the respective concentration‐time curves. 3. In the control subjects, basal salivary caffeine concentrations did not exceed 0.4 mg l‐1. The median (range) basal salivary caffeine concentrations in patients with compensated cirrhosis (n = 10), 0.2 (0‐0.7) mg l‐1 and decompensated cirrhosis (n = 9), 0.7 (0‐5.8) mg l‐1, were not significantly different from control values, although three patients with decompensated cirrhosis had basal salivary caffeine values above 2.0 mg l‐1. 4. In the patients with compensated cirrhosis, the median peak salivary caffeine concentration, 10.9 (8.2‐ 16.5) mg l‐1 was significantly greater than in controls, 7.1 (4.7‐11.8) mg l‐1 (P less than 0.01) and the median apparent volume of distribution was significantly reduced, 0.38 (0.19‐0.49) vs 0.41 (0.23‐ 0.63) l kg‐1 (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

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1. The clearance and biotransformation of caffeine (1,3,7-trimethylxanthine) were investigated in eight healthy control subjects and 16 patients with cirrhosis, by measuring serial serum caffeine concentrations and recoveries of methylxanthine metabolites in urine for 48 h after a 400 mg oral caffeine load. 2. In the control group, the mean (+/- SD) serum caffeine clearance was 1.3 +/- 0.4 ml min-1 kg-1 and a mean of 56.4 +/- 16.5% of the administered caffeine was recovered from the urine over 48 h as methyluric acids and methylxanthines. The majority of the metabolites were excreted in the first 24 h period and only 2.0 +/- 1.4% of the administered caffeine was excreted unchanged. 3. Patients with compensated cirrhosis (n = 10) metabolized caffeine similarly to the control subjects. Thus the mean serum caffeine clearance was 1.4 +/- 1.2 ml min-1 kg-1 and a mean of 57.2 +/- 11.7% of the administered caffeine was recovered from the urine over 48 h. The majority of the metabolites were excreted in the first 24 h; the pattern of metabolic excretion was unaltered and only 2.2 +/- 0.9% of the administered caffeine was excreted unchanged. 4. In the patients with decompensated cirrhosis (n = 6), significant changes were observed in caffeine metabolism. The mean serum caffeine clearance (0.4 +/- 0.2 ml min-1 kg-1) was significantly impaired compared with controls (P less than 0.01) and a significant delay was observed in metabolite excretion in the urine.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma D,L-2,3-butanediol was measured in 53 controls and 50 patients with alcoholic cirrhosis, none of whom had measurable amounts of blood ethanol. Thirteen of 50 samples from patients with alcoholic cirrhosis had measurable D,L-2,3-butanediol. (range less than 5-154 microM). In one patient with alcoholic cirrhosis who had been abstinent from ethanol for over 5 years plasma levels of D,L-2,3-butanediol ranged between 154 and 211 microM over a one-year period. Only one of the 53 control subjects had detectable levels of D,L-2,3-butanediol. Although it has previously been reported that 2,3-butanediol is present in alcoholics consuming distilled spirits (Rutstein et al. (1983) Lancet ii, 534), this is the first report of the persistent presence of these compounds in alcoholics in the absence of ethanol. Clearly in abstinent alcoholics the presence of 2,3-butanediol is not due to the ingestion of undistilled spirits nor is it likely to arise directly from the metabolic products of ethanol. The presence of D,L-2,3-butanediol in patients with alcoholic cirrhosis and its absence in control subjects suggests that this compound may be a marker of some forms for alcoholism.

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