Repirinast, a novel ingested
antiallergic asthma medication from Japan, was compared versus placebo on airway responsiveness to
methacholine and was compared versus placebo and
cromolyn on airway responses to
allergen. In 14 patients with mild, stable, atopic
asthma, we performed a double-blind, double-dummy, random-order trial with ingested
repirinast 300 mg twice daily for 7 days, inhaled
cromolyn 40 mg spincaps single dose, and double placebo on
allergen-induced early (EAR) and late (LAR) asthmatic responses and increased airway responsiveness. In the 14 subjects, no difference occurred in
methacholine PC20 after 6 days of
repirinast or 6 days of placebo. In the 13 subjects who completed the
allergen study, single-dose
cromolyn significantly reduced the EAR by 63% and the LAR by 65% versus placebo (p < 0.02);
repirinast was not significantly different from placebo, both the EAR and LAR being reduced by less than 10%.
Allergen-induced increase in
methacholine responsiveness was borderline (p = 0.052), and no significant
drug effects occurred. In these models, a 1-week treatment period with
repirinast, like other oral
antiallergic asthma medications (e.g.,
ketotifen, fumarate), provides no protection against airway responses to
methacholine or
allergen.