Single-dose effect of astemizole on bronchoconstriction induced by histamine in asthmatic subjects.
OBJECTIVE
Astemizole, administered for seven days to asthmatic subjects, had an effect of bronchoconstriction induced by inhaled histamine for a mean period of 42 days. This study evaluates whether a single dose of astemizole would have the same effect.


METHODS
Sixteen adult asthmatic subjects took part in the study.


METHODS
They first underwent three inhalation tests and skin prick tests with histamine on three different days. On the last day, a methacholine inhalation test was also performed. They subsequently received either a placebo or an active preparation of astemizole. The histamine inhalation test was repeated one day, two days, one week, and/or ten days after administering the drug.


RESULTS
Overall, no significant change in mean PC20 or in the mean diameter of the skin reaction to histamine was observed. However, three out of the eight subjects (38 percent) receiving active and none receiving placebo medication showed significant increases in PC20 histamine (p = 0.05). This effect lasted for one to two days.


CONCLUSIONS
We conclude that a single dose of 10 mg/ml of astemizole can have a significant effect on bronchial but not cutaneous reactivity to histamine. This effect is of short duration (one to two days).
Benoît
C
C
Department of Chest Medicine, Hôpital du Sacré-Coeur, Montreal, Canada.
Malo
J L
JL
Ghezzo
H
H
Cartier
A
A
D000328:Adult; D000368:Aged; D016589:Astemizole / Q000008:administration & dosage* / Q000494:pharmacology; D001249:Asthma / Q000276:immunology / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000187:drug effects*; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006632:Histamine / Q000276:immunology; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D012882:Skin Tests; D014797:Vital Capacity
D016210:Methacholine Chloride; D016589:Astemizole; D006632:Histamine