Protective effects of ketotifen on allergen‐induced bronchoconstriction and skin weal

Abstract

Abstract. A single‐blind cross‐over method was used to investigate the effects of ketotifen on the total respiratory resistance response curve to inhalation of a high concentration of allergen (1:5 w/v house dust or 1:10 w/v Japanese cedar pollen) and the weal response to intradermal injection of serially diluted allergen (1:103–1:106 w/v). Five subjects received 2 mg of ketotifen every 12 hr for the first week and an inactive placebo in the same manner for the second week. The remaining five subjects received the placebo for the first week and ketotifen for the second week. Ketotifen did not alter base‐line pulmonary function, but significantly delayed the time from the start of allergen exposure to the beginning of elevation of total respiratory resistance (P<0·02), and the time from the start of allergen exposure to the point at which total respiratory conductance decreased by 35% from the base‐line value (P<0·01). Ketotifen also decreased skin test sensitivity significantly (P<0·01)

Transcutaneous O₂ and CO₂ Monitoring of Bronchial Responsiveness in FEV₁ Non-Responder Asthmatics during Ketotifen and Placebo Treatment

“…Several bronchial provocation tests have demonstrated ketotifen protection against both the early and late reac tion due to allergic stimuli [19]. Ketotifen protection against the effects of non-specific bronchial challenges (particularly methacholine and exercise), on the other hand, has proved controversial [20,21].…”

Do diagnostic procedures other than inhalation challenge predict immediate bronchial responses to inhaled allergen?

“…As previously reported, we have developed an apparatus [5] for inhalation challenges with methacholine [6] and house dust (HD) allergen [7], Using the apparatus, throughout both inhalation challenges, bronchial responses can be continuously and graphically evaluated as a change in total respiratory resistance (Rrs) measured with the oscillation technique [Sj. Since these two tnethods entail very little discomfort for the patients, many outpatients have undergone bronchial challenges with methacholine and allergen in our clinic.…”