European Journal of Clinical Pharmacology

, Volume 44, Issue 1, pp 93–95

Oxaprotiline: enantioselective noradrenaline uptake inhibition indicated by intravenous amine pressor tests but not α2-adrenoceptor binding to intact platelets in man


  • I. W. Reimann
    • Human Pharmacology Institute Ciba-Geigy
  • L. Firkusny
    • Human Pharmacology Institute Ciba-Geigy
  • K. H. Antonin
    • Human Pharmacology Institute Ciba-Geigy
  • P. R. Bieck
    • Human Pharmacology Institute Ciba-Geigy
Short Communications

DOI: 10.1007/BF00315288

Cite this article as:
Reimann, I.W., Firkusny, L., Antonin, K.H. et al. Eur J Clin Pharmacol (1993) 44: 93. doi:10.1007/BF00315288


The optically active isomers of the racemic tetracyclic antidepressant oxaprotiline, R (−) oxaprotiline CGP 12 103 A (levoprotiline) and the S (+) oxaprotiline CGP 12 104 A, have been used as tools for a methodological Phase I study.

Only the S (+) enantiomer CGP 12 104 A inhibits noradrenaline uptake.

Intravenous amine pressor tests and ex vivo measurement of α2-adrenoceptor binding to intact human platelets were compared with respect to their reliability in indicating CGP 12 104 A-induced amine uptake inhibition and possibly associated α2-receptor down-regulation in healthy subjects.

α2-Adrenoceptor binding on intact human platelets did not distinguish between CGP 12 104 A and CGP 12 103 A.

However, amine pressor tests reflected the amine uptake inhibiting effect of CGP 12 104 A as a 5-fold decrease in tyramine pressor sensivity and a 5-fold increase in noradrenaline pressor sensitivity.

Key words

OxaprotilineLevoprotilinenoradrenaline uptake inhibitorsenantiomersCGP 12 103 ACGP 12 104 Aamine pressor testsα2-adrenoceptor bindingintact human platelets

Copyright information

© Springer-Verlag 1993