Effect of azelastine and ketotifen on the bronchial and skin responses to platelet-activating factor in humans.
In a randomized, double-blind placebo-controlled study we investigated the effect of single oral doses of 8 mg azelastine and 2 mg ketotifen on the immediate response to platelet-activating factor (PAF) inhalation and to increasing doses of PAF injected intradermally. Bronchial provocation with 100 micrograms of PAF resulted in marked bronchoconstrictor responses, but neither azelastine nor ketotifen had any significant effect on these responses. Intradermal injection of PAF (100, 200 and 400 ng) resulted in a dose-related weal and flare response. Azelastine and ketotifen both caused significant reductions in this response (P less than 0.002-P less than 0.01). There was no significant difference between the effect of the two drugs.
Immunopharmacology Group, Medicine I, Southampton General Hospital, U.K.
C K
CK
Lai
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Ollier
C K
CK
Lau
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Holgate
D000328:Adult; D016084:Bronchoconstriction / Q000187:drug effects*; D005260:Female; D005541:Forced Expiratory Volume; D006632:Histamine / Q000494:pharmacology; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D006801:Humans; D007665:Ketotifen / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010793:Phthalazines / Q000009:adverse effects / Q000494:pharmacology*; D010972:Platelet Activating Factor / Q000494:pharmacology*; D012867:Skin / Q000187:drug effects*
D006634:Histamine H1 Antagonists; D010793:Phthalazines; D010972:Platelet Activating Factor; D006632:Histamine; D007665:Ketotifen; C020976:azelastine