The effect of therapeutic doses of paracetamol on sulphur metabolism in man.

1. This study was designed to investigate the effect of prolonged paracetamol intake on sulphur metabolism in patients. Six patients, taking paracetamol in doses of 2-4 g d-1 and one taking 12 g d-1 took part in the study. Daily (24-h) collections of urine, and also plasma samples from these patients were analysed and in one case a study with additional methionine was performed. 2. The patients showed variable decrease in urinary output of inorganic sulphate but moderately raised plasma levels of inorganic sulphate. 3. Paracetamol metabolism was characterized by dominance of the glucuronidation pathway with the increase of the administered dose of paracetamol. Methionine added to the diet did not change this metabolic pattern. None of the subjects produced more than 0.6 mmol h-1 paracetamol sulphate while total sulphur excretion was 7.5-26.7 mmol d-1. 4. Volunteers taking 3 g d-1 paracetamol were also studied. 5. In persons taking a normal western diet containing over 20 mmol d-1 sulphur amino-acids paracetamol metabolism will not lead to sulphur amino-acid depletion even if high daily doses are used.