Thromb Haemost 1962; 08(01): 082-095
DOI: 10.1055/s-0038-1655414
Originalarbeiten — Original Articles — Travaux Originaux
Schattauer GmbH

Studies on the Coumarin Anticoagulant Drugs : The Assay of Warfarin and its Biologic Application[*]

Robert A. O’Reilly
1   Hematology Research Laboratory, Children’s Hospital, and the Department of Medicine, University of California School of Medicine, San Francisco, California
,
Paul M. Aggeler
1   Hematology Research Laboratory, Children’s Hospital, and the Department of Medicine, University of California School of Medicine, San Francisco, California
,
M Silvija Hoag
1   Hematology Research Laboratory, Children’s Hospital, and the Department of Medicine, University of California School of Medicine, San Francisco, California
,
Lois Leong
1   Hematology Research Laboratory, Children’s Hospital, and the Department of Medicine, University of California School of Medicine, San Francisco, California
› Institutsangaben
Weitere Informationen

Publikationsverlauf

Publikationsdatum:
14. Mai 2019 (online)

Summary

A spectrophotometric method is described for the determination of warfarin in biologic fluids. The warfarin is extracted from the specimen with acidified ethylene dichloride, washed with mild alkali and recovered from the organic phase with strong alkali. The extinction is then measured spectrophotometri-cally at the ultraviolet absorption maximum for warfarin. Results of UV absorption spectrophotometry and countercurrent distribution analysis showed that the assay is specific for unchanged warfarin in plasma; in addition, it measures a probable metabolite of warfarin in urine. Further studies indicated that the metabolite may be hydroxy-warfarin.

The method was applied in determining the absorption and elimination of warfarin after oral and intravenous administration. Gastrointestinal absorption of the drug was rapid and complete. With both routes the plasma concentrations and prothrombinopenic response were similar, and the rate of disappearance from the plasma followed an exponential decay curve. A correlation was found between rate of elimination and biologic response — the slower the rate of elimination, the more pronounced the depression of prothrombin complex activity. The application of this dual approach, the simultaneous study of the metabolic fate of the drug and the prothrombinopenic response, should provide a more rational basis for the therapeutic use of anticoagulant drugs.

* This study was supported by U. S. Public Health Service Grant H-2754 and by a grant from the Warner-Chilcott Co. Throughout these studies, the sodium salt of warfarin was used.


 
  • References

  • 1 Axelrod J, Cooper J. R, Brodie B. B. Estimation of Dicumarol, 3, 3’1-Methylenebis (4-Hydroxycoumarin) in Biological Fluids.. Proc. Soc. exp. Biol. (N. Y.) 1949; 70: 693
  • 2 Weiner M. Personal Communication..
  • 3 Quick A. J. The Physiology and Pathology of Hemostasis.. Lea & Febiger; Philadelphia: 1951: 188
  • 4 Craig L. C. Identification of Small Amounts of Organic Compounds by Distribution Studies. II. Separation by Counter-Current Distribution.. J. biol. Chem. 1944; 155: 519
  • 5 Brodie B. B, Weiner M, Burns J. J, Simson G, Yale E. K. The Physiological Disposition of Ethyl Biscoumacetate (Tromexan) in Man and a Method for its Estimation in Biological Material.. J. Pharmacol. exp. Ther. 1952; 106: 453
  • 6 Weiner M, Shapiro S, Axelrod J, Cooper J. R, Brodie B. B. The Physiological Disposition of Dicumarol in Man.. J. Pharmacol. exp. Ther. 1950; 99: 409
  • 7 Merck Index of Chemicals and Drugs.. 7th Edition. p. 1641. Merck & Co., Inc. Rahway, New Jersey: 1960: 1104
  • 8 Burns J. J, Weiner M, Simson G, Brodie B. B. The Biotransformation of Ethyl Biscoumacetate (Tromexan) in Man, Rabbit and Dog.. J. Pharmacol. exp. Ther 1953; 108: 33
  • 9 Hiskey C. F, Bullock E, Whitman G. Spectrophotometric Study of Aqueous Solutions of Warfarin Sodium.. J. Pharm. Sci. 1962; 51: 43
  • 10 Weiner N. Personal Communication..
  • 11 Gillam A. E, Stern E. S. An Introduction to Electronic Absorption Spectroscopy in Organic Chemistry.. 2nd Edition.. E. Arnold; London: 1957: 326
  • 12 Williams R. T. Detoxication Mechanisms.. 2nd Edition. John Wiley & Sons; New York: 1959: 796
  • 13 Fishman W. N. Chemistry of Drug Metabolism. C. C. Thomas, Springfield; Illinois: 1961: 235
  • 14 Mead J. A. R, Smith J. N, Williams R. T. Metabolism of Coumarin and o-Coumaric Acid.. Biochem. J. 1958; 68: 67
  • 15 Brodie B. B, Hogben C. A. M. Some Physico-Chemical Factors in Drug Action.. J. Pharm. 1957; 9: 345
  • 16 Snyder J. A. Studies on Warfarin. Dicumarol and Cyclocumarol. Ph. D. Thesis University of Wisconsin; 1953
  • 17 Preis S. The Resolution of Warfarin.. Ph. Dr. Thesis University of Wisconsin; 1958
  • 18 Klotz I. M, Walker F. M. The Binding of Organic Ions by Proteins. Charge and pH Effects.. J. Amer. chem. Soc. 1947; 69: 1609
  • 19 Wagner J. G. Biopharmaceutics: Absorption Aspects.. J. Pharm. Sci. 1961; 50: 359
  • 20 Schulert A. R, Weiner M. The Physiologic Disposition of Phenylindanëdione in Man.. J. Pharmacol. exp. Ther. 1954; 110: 451
  • 21 O’Reilly R. A, Aggeler P. M, Gibbs J. O. Hemorrhagic State Due to Surreptitious Ingestion of Dicumarol: A Detailed Case Study.. New Engl. J. Med. 1962; 267: 19
  • 22 Papworth D. S. A Review of the Dangers of Warfarin Poisoning to Animals Other than Rodents.. Roy. Soc. Hlth. J. 1958; 78: 52
  • 23 Nelson E. Therapeutic Considerations of Generic Name Prescriptions.. West. Pharm. 1961; 73: 9