Sunil K Chhabra, MD; and Shailendra...

Sunil K Chhabra, MD; and Shailendra N Gaur, MD FCCP

Several studies in the past have demonstrated a reduction in nonspecific bronchial hyperresponsiveness bring under rules with seasonal extrinsic asthma after long-term treatment with sodium cromoglycate. Since sodium cromoglycate is an effective put drugs into in the prophylactic treatment of all shadows of asthma, we assessed the force of a three-month treatment in succession nonspecific bronchial hyperresponsiveness in 11 patients with perennial asthma. Bronchial responsiveness was determined by means of histamine bronchoprovocation test, using SGaw as the index of lung function and uttered as [PD.sub.35]SGaw.

During the run-in period of single in kind month when sodium cromoglycate was not used, the histamine [PD.sub.35]SGaw decreased significantly from 015 [+ or -] 030 to 009 [+ or -] 029 mg/ml (p<0001) After three month of treatment with the medicine bronchial hyperresponsiveness was reduced significantly; the [PD.sub.35]SGaw was 021 [+ or -] 029 mg/ml (p<0001) It was conclud that long-term treatment of patients with perennial asthma with sodium cromoglycate consequence s in reduced bronchial hyperresponsiveness. (Chest 1989; 95:1235-38)

Sodium cromoglycate is a well established and effective prophylactic unsalable article for asthma, capable of inhibiting the one and the other immediate and late responses to antigen inhalation[1,2] as well as exercise-induced bronchospasm.[3,4] Nonspecific bronchial hyperresponsiveness to inhaled histamine or methacholine is a cardinal feature of asthma and correlates with several measures of severity of the disease.[5] The weight of sodium cromoglycate administration forward this characteristic of asthma has been investigated on several workers, at times with conflicting results[6-21] In all the studies take exception one,[18] only subjects with seasonal extrinsic asthma were included. The latter study[18] however, was confined to evaluation of the general intent of only a single dose of sodium cromoglycate. It is now well established that sodium cromoglycate is effective in all archetypes of asthma, irrespective of etiology.[22,23] No thought has been carried out previously upon the effect of longterm treatment with sodium cromoglycate upon nonspecific bronchial hyperresponsiveness in perennial asthma. With this aim, the ready study therefore was carried out

MATERIALS AND METHODS

studious mood Population and Design

Eleven make liables with perennial asthma, diagnosed according to history, physical examination and demonstration of significant reversibility of airway obstruction, were included in the contemplation The age range was from 11 to 32 years, and there were seven male and four female controls All of them were nonsmokers. In all the patients, several aggravating factors could be identified. These included viral infections, exercise, prospect to cold air and nonspecific irritants as it was as smoke and strong odors. In addition, they frequently had nocturnal attacks of bronchospasm and morning dipping. Four patients had, in addition, positive prototype 1 skin hypersensitivity reactions (2 +)[24] to public aeroallergens. The role of these allergens in the actual pathogenesis of the disease, however, was apparently minor as judg according to history. Because of the vicinity of a multiplicity of aggravating factors, known and unknown, in all the patients an exclusive etiologic categorization was not possible. Moreover, it was not considered necessary because nonspecific bronchial hyperresponsiveness is a universal feature in asthma and sodium cromoglycate is effective in all signs of asthma irrespective of etiologic factors. All of the patients required regular bronchodilator treatment (albuterol and theophylline). chiefly required one or more short courses of corticosteroids in a year.

The thought was divided into two phases--a run-in drug-free (when sodium cromoglycate was not used) phase of common month followed by a treatment phase with administration of sodium cromoglycate for three month Bronchoprovocation criterions were carried out three times: at the start (test 1) after the run-in phase (test 2) and after the treatment phase (test 3) During the treatment phase, sodium cromoglycate was given in a pulverize form, 20 mg inhaled from a spinhaler four times daily for three month Intercurrent symptoms during the run-in and treatment phases were treated with albuterol or terbutaline and theophylline whenever necessary. None of the patients required corticosteroids at any time during the close attention The patients were required to maintain a symptom diary from which the percentage of asymptomatic days was calculated at the extremity of the study.

Methods

Specific airway conductance was measured from an open-loop method[25] using a constant-volume dead body plethysmograph. The box crushing was calibrated for volume using a 30-ml sinusoidal tome signal with the subject inside the receptacle holding his breath. The bring under rule was required to breathe quietly between the sides of a Fleisch No. 3 pneumotachograph. coachman's seat pressure changes and differential pneumotachograph influences were measured with Statham PM 97 [+ or -] 005 and PM 283C [+ or -] 015 influence transducers. An X-Y intrigue of box pressure vs air sweep along was displayed on a storage oscilloscope. The direction downward of the inspiratory limb of the open-loop thus formed was measured with a protractor soared on the oscilloscope screen, and this provided the data for computation of SGaw.