Abstract
It is shown that the tricyclic antidepressant drug doxepin (comprising 15% of thecis- and 85% of thetrans-isomer) is a moderately potent competitive inhibitor of serotonin uptake in human blood platelets in vitro, with an inhibitory constantK i of about 2×10-7 M. The inhibitory effect was 6 times stronger in an artificial, protein-free medium than in diluted plasma, corresponding to about 85% protein binding. The efflux of serotonin from platelets preloaded with14C-serotonin was not affected by doxepin in concentrations up to 10-6 M, but increased rapidly at concentrations above 10-4 M.
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Lingjærde, O. Effect of doxepin on uptake and efflux of serotonin in human blood patelets in vitro. Psychopharmacology 47, 183–186 (1976). https://doi.org/10.1007/BF00735819
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DOI: https://doi.org/10.1007/BF00735819