Cross-over study of ten tetracycline preparations

  • J. Tuomisto
  • P. Männistö
Originals

Summary

Ten different brands of tetracycline were given to ten medical students in a cross-over study. A single dose of 500 mg was given, blood samples were taken 1,3,6, and 12 h later, and 24 h urines were collected. Peak serum levels of different preparations varied from 2.91±0.45 µg/ml to 4.32±0.31 µg/ml (mean±S.E.M.). According to both the area under the serum concentration-time curve as well as the total amount excreted in 24 h, the preparations could be divided into two poorly defined groups. Six preparations did not differ markedly from each other. Four other preparations gave lower values and differed significantly from two or more of the preparations of the first group. The smallest area and the lowest excretions were 68% and 74% of the largest area and the highest excretions, respectively. Although all the preparations gave adequate serum concentrations, four of them showed significantly lower absorptions — about 70 to 80% — than did the best brands.

Key words

Tetracycline absorption generic equivalence 

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References

  1. 1.
    Altman, A.E., Beeuwkes, H., Brombacker, P.J., Buytendijk, H.J., Gijzen, A.H.J., Maesen, F.P.V.: Serum levels of tetracycline after different administration forms. Clin. chim. Acta20, 185–188 (1968).Google Scholar
  2. 2.
    Barr, W.H., Gerbracht, L.M., Letcher, K., Plant, M., Strahl, N.: Assessment of the biologic availability of tetracycline products in man. Clin. Pharmacol. Ther.13, 97–108 (1972).Google Scholar
  3. 3.
    Brice, G.W., Hammer, H.F.: Therapeutic nonequivalency of oxytetracycline capsules. J. Amer. med. Ass.208, 1188–1189 (1969).Google Scholar
  4. 4.
    Gothoni, G., Neuvonen, P.J., af Björksten, K., Hackman, R.: On the factors influencing the absorption of tetracyclines. Suom. Lääk.-L.26, 259–263 (1971).Google Scholar
  5. 5.
    Kohn, K.W.: Determination of tetracyclines by extraction of fluorescent complexes. Analyt. Chem.33, 862–866 (1961).Google Scholar
  6. 6.
    Kunin, C.M., Finland, M.: Clinical pharmacology of the tetracycline antibiotics. Clin. Pharm. Ther.2, 51–69 (1961).Google Scholar
  7. 7.
    MacDonald, H., Pisano, F., Burger, J.: Physiologic availability of various tetracyclines. Clin. med.76, 12, 30–33 (1969).Google Scholar
  8. 8.
    Mattila, M.J., Neuvonen, P.J., Gothoni, G., Hackman, C.R.: Interference of iron preparations and milk with the absorption of tetracyclines. Excerpta med. Int. Congr. Ser.254, 128–133 (1971).Google Scholar
  9. 9.
    Medical News: 40 million antibiotic capsules recalled. J. Amer. med. Ass.210, 2350 (1969).Google Scholar
  10. 10.
    Neuvonen, P.J., Gothoni, G., Hackman, R., af Björksten, K.: Interference of iron with the absorption of tetracyclines in man. Brit. J. Med.4, 532–534 (1970).Google Scholar
  11. 11.
    Steigbigel, N.H., Reed, C.W., Finland, M.: Absorption and excretion of five tetracycline analogues in normal young men. Amer. J. med. Sci.255, 296–312 (1968).Google Scholar
  12. 12.
    Walter, A.M., Heilmeyer, L.: Antibiotica-Fibel. Stuttgart: Thieme 1969.Google Scholar

Copyright information

© Springer-Verlag 1973

Authors and Affiliations

  • J. Tuomisto
    • 1
  • P. Männistö
    • 1
  1. 1.Department of PharmacologyUniversity of HelsinkiHelsinkiFinland

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