Augmentation of human blood acetylsalicylate concentrations by the simultaneous administration of acetaminophen with aspirin
Cotty, V.F.; Sterbenz, F.J.; Mueller, F.; Melman, K.; Ederma, H.; Skerpac, J.; Hunter, D.; Lehr, M.
Toxicology and Applied Pharmacology 41(1): 7-13
1977
ISSN/ISBN: 0041-008X PMID: 898192 Document Number: 117560
Higher than anticipated blood concentrations of unhydrolyzed acetylsalicylic acid were found during a bioavailability study of an experimental mixed analgesic tablet. The phenomenon was confirmed by means of contemporaneous crossover studies with 20 or 21 volunteers. The subjects received aspirin or drug mixtures as pure powders suspended in water in the 1st experiment and as tablets producing similar total salicylate blood concentrations in the 2nd. Blood acetylsalicylic acid concentrations were increased when 650 mg of aspirin were administered with acetaminophen as compared with those found after dosing with 650 mg of aspirin alone. This increase in the blood concentration of unhydrolyzed aspirin was not due to an increase in the total amount of aspirin absorbed.