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Summary

Six healthy volunteers received oxazepam 15 mg i.v. and orally at an interval of at least one week. The kinetic variables of i.v. oxazepam were: elimination half-life (t1/2β) 6.7 h, total clearance (CL) 1.07 ml·min−1·kg−1, volume of distribution (Vc) 0.27 l·kg−1 (0.21–0.49) and volume of distribution at steady-state (Vss) 0.59 l·kg−1. The intravenous disposition of unbound oxazepam was characterized by a clearance of 22.5ml·min−1·kg−1 and a distribution volume of 12.3 l·kg−1. After oral oxazepam the peak plasma level was reached in 1.7 to 2.8 h. The plasma t1/2β at 5.8 h was not significantly different from the i.v. value. Absorption was almost complete, with a bioavailability of 92.8%. Urinary recovery was 80.0 and 71.4% of the dose after intravenous and oral administration, respectively. Renal clearance (CLR) of the glucuronide metabolite was 1.10 ml·min−1·kg−1 (0.98–1.52). Oxazepam was extensively bound to plasma protein with a free fraction of 4.5%.

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References

  1. Greenblatt DJ, Shader RI, Koch-Weser J (1975) Pharmacokinetics in clinical medicine. Oxazepam versus other benzodiazepines. Dis Nerv Syst 36: (no. 5, section 2) 6–13

    Google Scholar 

  2. Chinnery R, Sundwall A (1978) Pharmacodynamic, pharmacokinetic and clinical aspects on oxazepam and related benzodiazepines. Acta Psychiatr Scand 274 [Suppl]: 1–128

    Google Scholar 

  3. Wretlind M, Pilbrant A, Sundwall A, Vessman J (1977) Disposition of three benzodiazepines after single oral administration in man. Acta Pharmacol Toxicol 40 [Suppl 1]: 28–39

    Google Scholar 

  4. Greenblatt DJ (1981) Clinical pharmacokinetics of oxazepam and lorazepam. Clin Pharmacokinet 6: 89–105

    Google Scholar 

  5. Ochs HR, Greenblatt DJ, Otten H (1981) Disposition of oxazepam in relation to age, sex, and cigarette smoking. Klin Wochenschr 59: 899–903

    Google Scholar 

  6. Murray TG, Chiang ST, Koepke HH, Walker BR (1981) Renal disease, age, and oxazepam kinetics. Clin Pharmacol Ther 30: 805–809

    Google Scholar 

  7. Greenblatt DJ, Murray TG, Audet PR, Locniskar A, Koepke HH, Walker BR (1983) Multiple-dose kinetics and dialyzability of oxazepam in renal insufficiency. Nephron 34: 234–238

    Google Scholar 

  8. Greenblatt DJ, Divoll M, Harmatz JS, Shader RI (1980) Oxazepam kinetics: Effects of age and sex. J Pharmacol Exp Ther 215: 86–91

    Google Scholar 

  9. Patwardhan RV, Yarborough GW, Desmond PV, Johnson RF, Schenker S, Speeg KV (1980) Cimetidine spares the glucuronidation of lorazepam and oxazepam. Gastroenterology 79: 912–916

    Google Scholar 

  10. Moschitto LJ, Greenblatt DJ (1983) Concentration-independent plasma protein binding of benzodiazepines. J Pharm Pharmacol 35: 179–180

    Google Scholar 

  11. Weder HG, Schildknecht J, Kesselring P (1971) A new equilibrium dialyzing system. Am Lab 10: 15–21

    Google Scholar 

  12. Christensen JH, Andreasen F, Jensen EB (1980) The binding of thiopental to serum proteins determined by ultrafiltration and equilibrium dialysis. Acta Pharmacol Toxicol 47: 24–32

    Google Scholar 

  13. Brown DR, Manno JE (1978) ESTRIP, a BASIC computer program for obtaining initial polyexponential parameter estimates. J Pharm Sci 67: 1687–1691

    Google Scholar 

  14. Gibaldi M, Perrier D (1975) Drugs and the pharmaceutical sciences, Vol 1: Pharmacokinetics. Marcel Dekker, New York

    Google Scholar 

  15. Kelner MJ, Bailey DN (1985) Propylene glycol as a cause of lactic acidosis. J Anal Toxicol 9: 40–42

    Google Scholar 

  16. Van Hecken AM, Tjandramaga B, Verbesselt R, De Schepper PJ (1985) The influence of diflunisal on the pharmacokinetics of oxazepam. Br J Clin Pharmacol 20: 225–234

    Google Scholar 

  17. Wilkinson GR, Shand DG (1975) A physiological approach to drug clearance. Clin Pharmacol Ther 18: 377–390

    Google Scholar 

  18. Bliding A (1974) Effects of different rates of absorption of two benzodiazepines on subjective and objective parameters. J Clin Pharmacol 7: 201–211

    Google Scholar 

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Sonne, J., Loft, S., Døssing, M. et al. Bioavailability and pharmacokinetics of oxazepam. Eur J Clin Pharmacol 35, 385–389 (1988). https://doi.org/10.1007/BF00561369

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  • DOI: https://doi.org/10.1007/BF00561369

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