title: Impaired absorption of paracetamol in vegetarians.
abstract: 1. The absorption and disposition of paracetamol was investigated in 10 healthy male Thai vegetarians and 10 similar non-vegetarians following an oral dose of 20 mg kg-1. 2. The absorption rate of paracetamol was significantly impaired in the vegetarians compared with the non-vegetarians as shown by a lower mean Cmax (11.7 +/- 1.4 vs 15.6 +/- 1.6 mg l-1; 95% confidence interval of the difference 2.49 to 5.36), increased tmax (median 1.75, range 0.75 to 3 h compared with 0.75 and 0.25 to 2 h) and an increase in the time for input of 50% of the total amount absorbed (0.54 +/- 0.38 compared with 0.20 +/- 0.10 h; 95% confidence interval of the difference 0.063 to 0.61). 3. A significantly lower total 24 h urinary recovery of paracetamol and metabolites (72.1 +/- 5.4 vs 86.4 +/- 5.4% of the dose; 95% confidence interval of the difference 8.0 to 20.6) indicated a decrease in the extent of absorption in the vegetarians also, although the total AUC values did not differ significantly between the two groups. 4. The plasma paracetamol half-life, partial metabolic clearances and fractional urinary excretion of the glucuronide, sulphate, cysteine and mercapturic acid conjugates of paracetamol were similar in the vegetarians and non-vegetarians.
authors.affiliation: University Department of Clinical Pharmacology, Royal Infirmary, Edinburgh, Scotland.
authors.forename: L F
authors.initials: LF
authors.lastname: Prescott
authors.forename: K
authors.initials: K
authors.lastname: Yoovathaworn
authors.forename: K
authors.initials: K
authors.lastname: Makarananda
authors.forename: R
authors.initials: R
authors.lastname: Saivises
authors.forename: K
authors.initials: K
authors.lastname: Sriwatanakul
mesh_terms: D000042:Absorption; D000082:Acetaminophen / Q000097:blood / Q000493:pharmacokinetics*; D000284:Administration, Oral; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000493:pharmacokinetics*; D014676:Diet, Vegetarian; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen