Prevention of antigen-induced bronchoconstriction by lodoxamide ethyl, a new orally active antiallergic drug

Abstract Lodoxamide ethyl, an orally active drug with pharmacologic activity similar to that of cromolyn sodium, blocks passive cutaneous anaphylaxis (PCA) in rats and antigen-induced bronchoconstriction in guinea pigs and monkeys. Its effectiveness in preventing antigen-induced airway obstruction was studied in 12 asymptomatic asthmatic adults with immediate skin test sensitivity to ragweed, Alternaria , or animal dander. The dose required to reduce the forced expiratory volume in 1 sec (FEV 1 ) by 20% (PD 20 ) was determined by dosimeter bronchoprovocation challenge with the appropriate antigen. At 1-wk intervals each subject received either placebo or 1, 3, or 10 mg drug in a randomized, double-blind fashion 30 min prior to starting bronchoprovocation challenge. On average, 1 mg increased the PD 20 fivefold, 3 mg about sixfold, and 10 mg about 27-fold. Dose-related side effects began 10 min after drug and lasted up to 40 min. Thus the oral administration of lodoxamide ethyl was effective in preventing antigen-induced bronchoconstriction, and both the beneficial effects and side effects are dose related.