Objectives: We analysed and compared the effect of five H1-antihistamines on stimulated oxidative burst at extra- and intracellular level of isolated and stimulated human polymorphonuclear leukocytes.
Design: Oxidative burst of isolated human neutrophils was studied by means of luminol and isoluminol enhanced chemiluminescence.
Results: The following rank order of potency for H1-antihistamines to decrease chemiluminescence was evaluated extracellularly: dithiaden> loratadine> chlorpheniramine> brompheniramine> pheniramine and at intracellular site: loratadine> dithiaden.
Conclusion: H1-antihistamines differ substantially according to their chemical structure in suppressing oxidative burst both at extra- and intracellular site of isolated stimulated human neutrophils.