Summary
Single doses of effervescent tablets (1200 mg) and enteric coated (EC) tablets (1300 mg and 650 mg) of acetylsalicylic acid (aspirin, ASA) were given to healthy volunteers in random order. Plasma ASA and salicylic acid (SA) levels were measured and concurrent in vitro measurements of the volunteers' platelet aggregation were carried out. The effervescent preparation resulted in peak ASA concentrations of 17–40 mg/l, achieved 20 to 30 min after a 1200 mg dose, whereas peak ASA levels of 0.01–0.37 mg/l were observed 4–6 h after a 650 mg dose of the EC preparation. With all the aggregating agents that were added to the test system maximum inhibition of platelet aggregation (about 50% of pre dose levels) was seen 1.0 h after the effervescent ASA dose, and persisted to at least 24 h, but with the EC preparation not until 24 h, at which time the degree of inhibition was also about 50% of pre-dose levels. A 1.0 g dose of sodium salicylate had no effect on in vitro platelet function. It was concluded that mean plasma levels of ASA of less than 0.25 mg/l are sufficient to depress aggregation by approximately 50%. A low dose of ASA taken daily either as effervescent ASA or EC ASA, significantly inhibits platelet aggregation and so may reduce the risk of ischaemic episodes in susceptible patients.
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Ali M, McDonald JWD, Thiessen JJ, Coates PE (1980) Plasma acetylsalicylate and salicylate and platelet cyclo-oxygenase activity following plain and enteric-coated aspirin. Stroke 11: 9–13
Aspirin Myocardial Infarction Study Research Group (1980) The Aspirin Myocardial Infarction Study: final results. Circulation 62 [Suppl 5]: 79–84
Barnett JH and the Canadian Co-operative Study Group (1978) A randomized trial of aspirin and sulphinpyrazone in threatened stroke. N Engl J Med 299: 53–59
Born GVR (1962) Aggregation of blood platelets by adenosine diphosphate and its reversal. Nature (London) 194: 927–929
Breddin K, Loew O, Lechner K, Oberla K, Walter E (1980) The German-Austrian Aspirin Trial: A comparison of acetylsalicylic acid, placebo and phenprocoumon in secondary prevention of myocardial infarction. Circulation 62 [Suppl 5]: 63–72
Burch JW, Stanford N, Marjerus PW (1978) Inhibition of platelet prostaglandin synthetase by oral aspirin. J Clin Invest 61: 314–319
Cham BE, Ross-Lee L, Bochner F, Imhoff D (1980) Measurement and pharmacokinetics of acetylsalicylic acid by a novel high-performance liquid chromatographic assay. Ther Drug Monitoring 2: 365–372
Clark RL, Lasagna L (1965) How reliable are enteric coated aspirin preparations? Clin Pharmacol Ther 6: 568–574
Coronary Drug Project Research Group (1980) Aspirin in coronary heart disease. Circulation 62 [Suppl 5]: 59–62
Farah AE, Rosenberg F (1980) Potential therapeutic applications of aspirin and other cyclo-oxygenase inhibitors. Br J Clin Pharmacol 10: 261–278
Field WS, Lemark NA, Frankowski RF (1977) Controlled trial of aspirin in cerebral ischaemia (part I) Stroke 8: 301–316
Genua MI, Giraldez J, Rocha F, Monge A (1980) Effects of antibiotics on platelet functions in human plasma in vitro and dog plasma in vivo. J Pharm Sci 69: 1282–1284
Hennekens CH, Karlson LK, Rosner B (1978) A case-control study of regular aspirin use and coronary deaths. Circulation 58: 35
Paccioretti MJ, Block LH (1980) Effect of aspirin on platelet aggregation as a function of dosage and time. Clin Pharmacol Ther 27: 803–809
Vanderhoek JY, Makheja AN, Baily JM (1980) Inhibition of fatty acid oxygenases by onion and garlic oils — evidence for the mechanism by which these oils inhibit platelet aggregation. Biochem Pharmacol 29: 3169–3173
Vane JR (1971) Inhibition of prostaglandin synthesis as a mechanism of action for aspirin-like drugs. Nature (New Biol) 231: 232–235
Walter E, Zimmerman R, Siess R, Staiger C, Weber E (1980) Biphasic initial phase of platelet aggregation inhibition after oral aspirin. Artery 8: 501–506
Weiss HJ, Aledort LM, Kochwa S (1968) The effect of salicylates on the haemostasis properties of platelets in man. J Clin Invest 47: 2169–2180
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Ross-Lee, L.M., Elms, M.J., Cham, B.E. et al. Plasma levels of aspirin following effervescent and enteric coated tablets, and their effect on platelet function. Eur J Clin Pharmacol 23, 545–551 (1982). https://doi.org/10.1007/BF00637504
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DOI: https://doi.org/10.1007/BF00637504