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New pharmacological profiles of loratadine: Effects on platelet aggregation and histamine release from repository cells


Loratadine is endowed with antiallergic activity. It reduces both the immunological release of histamine in active anaphylaxis of isolated guinea-pig mast cells and in anti-IgE challenged human basophils as well as the non-immunological release of histamine induced by compound 48/80 and calcium ionophore A 23187 in isolated purified rat serosal mast cells. Loratadine was also found capable of directly reducing platelet aggregation induced by different agonists in a concentration-dependent fashion. It is capable of blocking the potentiation afforded by histamine on human platelet aggregation induced by thrombin, collagen and arachidonic acid. The present results suggest a broader profile for loratadine beyond its original role as a non-sedative anti-H1-antihistaminic drug.

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Pistelli, A., Di Bello, M.G., Raspanti, S. et al. New pharmacological profiles of loratadine: Effects on platelet aggregation and histamine release from repository cells. Agents and Actions 38, C200–C202 (1993).

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  • Mast Cell
  • Histamine
  • Thrombin
  • Platelet Aggregation
  • Loratadine