Allergic Asthma

The main finding of this study was that a sufficiently high dose of chlorpheniramine administered intravenously can protect against mild attacks of allergen-induced asthma on the basis of its Hi blocking properties. A second and quite unexpected finding was that regardless of the degree of bronchial reactivity to histamine, a fixed dose of chlorpheniramine given intravenously produced a comparable rate of protection against histamine-induced bronchoconstriction. The implication of the first finding is that in asthma,

The anthropometric and respiratory measurements of the subjects participating in this study are shown in Table 1. The same table shows the TDs of allergen, histamine, and when determined, acety-choline. The range of TDs of histamine was sixteenfold, between 0.08 and 1.28 mg. See articles in our site:  https://onlineasthmainhalers.com/category/pathogenesis . The average change at the threshold level varied with the measurement: 3.0 to 8.0 percent for FVC, 11.3 to 18.6 percent for FEVi, and 16.0 to

Fifteen subjects with bronchial asthma were initially enrolled in the study, and selected according to the following criteria: age between 20 and 30, in an asthma-free interval, (ie, no attack of asthma in the last four weeks), clear cut history of attacks of asthma triggered by a well defined environmental allergen, and positive skin (prick) and radio-allergosorbent (RAST) tests to that allergen. Because 10 mg of intravenously administered chlorpheniramine dilates the bronchi only if FEV1 is low,

It is generally accepted that histamine is released in vivo when actively or passively sensitized fragments of lung, tracheobronchial strips, nasal polyps, or basophils are challenged with the appropriate allergen. In vivo, the blood level of histamine is increased during spontaneous or allergen-induced attacks of asthma. Moreover, at least in vivo, the asthmatic bronchi are hyperreactive to exogenous histamine, and thus, most likely to endogenous histamine as well. Yet, as repeatedly shown, the Hi blockers