Abstract
1. Four healthy male subjects received racemic ibuprofen (200, 400, 800 and 1200 mg), orally, on four occasions, 2 weeks apart, according to a four-way Latin-square design, in order to investigate the influence of increasing dose of ibuprofen on the magnitude and duration of its antiplatelet effect as well as on the relationship between such effect and drug concentration. 2. The antiplatelet effect of ibuprofen was assessed by measuring the inhibition of platelet thromboxane B2 (TXB2) generation during the controlled clotting of whole blood. The plasma unbound concentration of S(+)-ibuprofen, the enantiomer shown in an in vitro study to be responsible for the inhibitory effect of platelet TXB2 generation, was measured using an enantioselective method. 3. The maximum percentage inhibition of TXB2 generation increased significantly with dose from a mean +/- s.d. of 93.4 +/- 1.2% after the 200 mg dose to 98.8 +/- 0.3% after the 1200 mg dose, and there was an increase with dose in the duration of inhibition of TXB2 generation. The effect of ibuprofen on platelet TXB2 generation was transient and mirrored the time-course of unbound S(+)-ibuprofen in plasma; on all but one of the 16 occasions, serum TXB2 concentrations returned to at least within 10% of the pretreatment concentrations within 24 h of ibuprofen administration. 4. For each subject, the relationship between the percentage inhibition of TXB2 generation and the unbound concentration of S(+)-ibuprofen in plasma was modelled according to a sigmoidal Emax equation. The mean plasma unbound concentration of S(+)-ibuprofen required to inhibit platelet TXB2 generation by 50% (EC50) was 9.8 +/- 1.0 micrograms l-1.(ABSTRACT TRUNCATED AT 250 WORDS)
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Selected References
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- Adams S. S., Bresloff P., Mason C. G. Pharmacological differences between the optical isomers of ibuprofen: evidence for metabolic inversion of the (-)-isomer. J Pharm Pharmacol. 1976 Mar;28(3):256–257. doi: 10.1111/j.2042-7158.1976.tb04144.x. [DOI] [PubMed] [Google Scholar]
- Brooks C. D., Schlagel C. A., Sekhar N. C., Sobota J. T. Tolerance and pharmacology of ibuprofen. Curr Ther Res Clin Exp. 1973 Apr;15(4):180–190. [PubMed] [Google Scholar]
- Cerletti C., Marchi S., Lauri D., Domanin M., Lorenzi G., Urso R., Dejana E., Latini R., de Gaetano G. Pharmacokinetics of enteric-coated aspirin and inhibition of platelet thromboxane A2 and vascular prostacyclin generation in humans. Clin Pharmacol Ther. 1987 Aug;42(2):175–180. doi: 10.1038/clpt.1987.128. [DOI] [PubMed] [Google Scholar]
- Cox S. R., VanderLugt J. T., Gumbleton T. J., Smith R. B. Relationships between thromboxane production, platelet aggregability, and serum concentrations of ibuprofen or flurbiprofen. Clin Pharmacol Ther. 1987 May;41(5):510–521. doi: 10.1038/clpt.1987.66. [DOI] [PubMed] [Google Scholar]
- Cronberg S., Wallmark E., Söderberg I. Effect on platelet aggregation of oral administration of 10 non-steroidal analgesics to humans. Scand J Haematol. 1984 Aug;33(2):155–159. doi: 10.1111/j.1600-0609.1984.tb02390.x. [DOI] [PubMed] [Google Scholar]
- Day R. O. Mode of action of non-steroidal anti-inflammatory drugs. Med J Aust. 1988 Feb 15;148(4):195–199. [PubMed] [Google Scholar]
- Evans A. M., Nation R. L., Sansom L. N., Bochner F., Somogyi A. A. Stereoselective plasma protein binding of ibuprofen enantiomers. Eur J Clin Pharmacol. 1989;36(3):283–290. doi: 10.1007/BF00558161. [DOI] [PubMed] [Google Scholar]
- Evans A. M., Nation R. L., Sansom L. N., Bochner F., Somogyi A. A. The relationship between the pharmacokinetics of ibuprofen enantiomers and the dose of racemic ibuprofen in humans. Biopharm Drug Dispos. 1990 Aug-Sep;11(6):507–518. doi: 10.1002/bdd.2510110605. [DOI] [PubMed] [Google Scholar]
- Evans A. M., Nation R. L., Sansom L. N. Lack of effect of cimetidine on the pharmacokinetics of R(-)- and S(+)-ibuprofen. Br J Clin Pharmacol. 1989 Aug;28(2):143–149. doi: 10.1111/j.1365-2125.1989.tb05406.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fitzpatrick F. A. A radioimmunoassay for thromboxane B2. Methods Enzymol. 1982;86:286–297. doi: 10.1016/0076-6879(82)86201-0. [DOI] [PubMed] [Google Scholar]
- Friedhoff L. T., Manning J., Funke P. T., Ivashkiv E., Tu J., Cooper W., Willard D. A. Quantitation of drug levels and platelet receptor blockade caused by a thromboxane antagonist. Clin Pharmacol Ther. 1986 Dec;40(6):634–642. doi: 10.1038/clpt.1986.238. [DOI] [PubMed] [Google Scholar]
- Hamberg M., Svensson J., Samuelsson B. Thromboxanes: a new group of biologically active compounds derived from prostaglandin endoperoxides. Proc Natl Acad Sci U S A. 1975 Aug;72(8):2994–2998. doi: 10.1073/pnas.72.8.2994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Holford N. H., Sheiner L. B. Kinetics of pharmacologic response. Pharmacol Ther. 1982;16(2):143–166. doi: 10.1016/0163-7258(82)90051-1. [DOI] [PubMed] [Google Scholar]
- Ikeda Y. The effect of ibuprofen on platelet function in vivo. Keio J Med. 1977 Dec;26(4):213–222. doi: 10.2302/kjm.26.213. [DOI] [PubMed] [Google Scholar]
- Kean W. F., Lock C. J., Rischke J., Butt R., Buchanan W. W., Howard-Lock H. Effect of R and S enantiomers of naproxen on aggregation and thromboxane production in human platelets. J Pharm Sci. 1989 Apr;78(4):324–327. doi: 10.1002/jps.2600780413. [DOI] [PubMed] [Google Scholar]
- Kulmacz R. J., Lands W. E. Stoichiometry and kinetics of the interaction of prostaglandin H synthase with anti-inflammatory agents. J Biol Chem. 1985 Oct 15;260(23):12572–12578. [PubMed] [Google Scholar]
- Lee E. J., Williams K., Day R., Graham G., Champion D. Stereoselective disposition of ibuprofen enantiomers in man. Br J Clin Pharmacol. 1985 May;19(5):669–674. doi: 10.1111/j.1365-2125.1985.tb02694.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Longenecker G. L., Swift I. A., Bowen R. J., Beyers B. J., Shah A. K. Kinetics of ibuprofen effect on platelet and endothelial prostanoid release. Clin Pharmacol Ther. 1985 Mar;37(3):343–348. doi: 10.1038/clpt.1985.50. [DOI] [PubMed] [Google Scholar]
- McIntyre B. A., Philp R. B., Inwood M. J. Effect of ibuprofen on platelet function in normal subjects and hemophiliac patients. Clin Pharmacol Ther. 1978 Nov;24(5):616–621. doi: 10.1002/cpt1978245616. [DOI] [PubMed] [Google Scholar]
- Mustard J. F., Kinlough-Rathbone R. L., Packham M. A. Prostaglandins and platelets. Annu Rev Med. 1980;31:89–96. doi: 10.1146/annurev.me.31.020180.000513. [DOI] [PubMed] [Google Scholar]
- Nuotto E., Gordin A., Paasonen M. K., Metsä-Ketelä T., Lamminsivu U. Effect of acetylsalicylic acid on plasma thromboxane B2 and platelet aggregation in man. Eur J Clin Pharmacol. 1983;25(3):313–317. doi: 10.1007/BF01037940. [DOI] [PubMed] [Google Scholar]
- O'Brien J. R. Effect of anti-inflammatory agents on platelets. Lancet. 1968 Apr 27;1(7548):894–895. doi: 10.1016/s0140-6736(68)90242-0. [DOI] [PubMed] [Google Scholar]
- Parks W. M., Hoak J. C., Czervionke R. L. Comparative effect of ibuprofen on endothelial and platelet prostaglandin synthesis. J Pharmacol Exp Ther. 1981 Nov;219(2):415–419. [PubMed] [Google Scholar]
- Patrignani P., Filabozzi P., Patrono C. Selective cumulative inhibition of platelet thromboxane production by low-dose aspirin in healthy subjects. J Clin Invest. 1982 Jun;69(6):1366–1372. doi: 10.1172/JCI110576. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Patrono C., Ciabattoni G., Pinca E., Pugliese F., Castrucci G., De Salvo A., Satta M. A., Peskar B. A. Low dose aspirin and inhibition of thromboxane B2 production in healthy subjects. Thromb Res. 1980 Feb 1;17(3-4):317–327. doi: 10.1016/0049-3848(80)90066-3. [DOI] [PubMed] [Google Scholar]
- Rao G. H., Johnson G. G., Reddy K. R., White J. G. Ibuprofen protects platelet cyclooxygenase from irreversible inhibition by aspirin. Arteriosclerosis. 1983 Jul-Aug;3(4):383–388. doi: 10.1161/01.atv.3.4.383. [DOI] [PubMed] [Google Scholar]
- Rubin A., Knadler M. P., Ho P. P., Bechtol L. D., Wolen R. L. Stereoselective inversion of (R)-fenoprofen to (S)-fenoprofen in humans. J Pharm Sci. 1985 Jan;74(1):82–84. doi: 10.1002/jps.2600740122. [DOI] [PubMed] [Google Scholar]
- Smith J. B., Ingerman C., Silver M. J. Persistence of thromboxane A2-like material and platelet release-inducing activity in plasma. J Clin Invest. 1976 Nov;58(5):1119–1122. doi: 10.1172/JCI108564. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams K., Day R., Knihinicki R., Duffield A. The stereoselective uptake of ibuprofen enantiomers into adipose tissue. Biochem Pharmacol. 1986 Oct 1;35(19):3403–3405. doi: 10.1016/0006-2952(86)90443-0. [DOI] [PubMed] [Google Scholar]