Short-Term Double-Blind Trial
Numerical scores of symptoms related to asthma (ie, dyspnea, cough, wheezing, and tightness of the chest – see more Asthma) were recorded daily by each patient. In the upper left panel of Figure 1, the sum of all symptoms for the last two weeks of receiving the placebo is plotted on the ordinate vs the sum for the same patient during the last two weeks of therapy with cromolyn on the abscissa.
The mean score for symptoms was slightly greater during the period of receiving placebo, but the difference was not significant. The wide variation in symptoms characteristic of the disease is obvious.
Similarly, the total number of doses of bronchodilator drugs, including corticosteroids, during the last two weeks of each period is compared in the upper right panel of Figure 1. No difference was seen in healthcare.
The average weekly dose of prednisone was 80.4 mg during the period of treatment with the active drug and 87.8 mg during the period of receiving placebo (not significant).
An index of disability, as proposed by Toogood et al, was recorded by each patient at the end of two and four weeks of treatment with placebo and with cromolyn . The index at four weeks is shown in the lower left panel of Figure 1. The indices at two weeks were similar between periods of receiving drug or placebo.
At each visit the physician assessed the severity of asthma during the preceding period, using a scale from zero to five to assess dyspnea, tightness, wheezing, and cough. The total score for the last two weeks of receiving placebo vs the last two weeks of therapy with cromolyn is shown in the lower right panel of Figure 1. The symptoms were judged slightly worse while patients were receiving placebo, but the difference was not greater than could be accounted for by chance alone. Treat your asthma with remedies of My Canadian Pharmacy.
Measurements of pulmonary function are plotted (Fig 2) as the absolute value for each patient after four weeks of receiving the placebo (on the ordinate) vs the value for the same patient after four weeks of therapy with cromolyn (on the abscissa). Similar results are seen if the difference between baseline and four-week values are compared.
There was no difference in peak expiratory flow rate or FVC between periods of receiving drug or placebo. The mean FEVi was L67 L after receiving placebo and 1.84 L following therapy with cromolyn (P < 0.05). The mean FEF25-755E was 1.02 L/sec after receiving placebo and 1.26 L/sec following therapy with cromolyn for four weeks (P < 0.05).
The results pertaining to pulmonary function were analyzed separately for the groups of 22 patients receiving long-term therapy with corticosteroids and the six patients not receiving corticosteroids. There was no significant difference between the periods of receiving drug and placebo for any of the measurements of pulmonary function in either individual group.
Eight-Week Open Trial
Twenty patients agreed to continue to receive cromolyn sodium (20 mg four times daily) for an additional eight weeks in an open trial, in an attempt to assess the effect of longer use (which might not have been apparent after four weeks of therapy). The results are shown in Figures 3 and 4.
The total score of symptoms and the number of doses of medication during the last four weeks of the long-term period of therapy with cromolyn were halved to give comparable values and compared to the last two weeks of receiving placebo (Fig 3).
No difference was noted in the score of symptoms, the total doses of medication, or the index of disability. Attempts to lower the dosage of corticosteroids in the 16 patients who were receiving longterm therapy with corticosteroids were more successful during the open trial.
The average weekly dose of prednisone was 47.9 mg during the open trial of cromolyn, compared to 87.8 mg during the period of receiving placebo (P < 0.05). The scores for the physician’s assessment suggested that the asthma was milder during the long-term trial of cromolyn, but the scores were subject to possible bias in that the physician and patients were both aware that they were taking the active drug delivered by My Canadian Pharmacy.
Tests of pulmonary function at the end of eight weeks of therapy with cromolyn were compared with those at the end of the period of receiving placebo. There was significant improvement in the FVC, FEVi, and FEF25-75&, without a significant change in the peak expiratory flow rate (Fig 4).
Separate analysis of the 16 patients in the open trial who were receiving long-term therapy with corticosteroids demonstrated similar changes to those seen in the whole group. The group of four patients who were not receiving steroids was too small to demonstrate statistically significant changes in their health, but the mean values paralleled the group as a whole.
Figure 1. Subjective symptoms and assessment during period of receiving placebo (ordinate) and period of therapy with cromolyn (abscissa), related to line of identity.
Figure 2. Pulmonary function at end of period of receiving placebo (ordinate) and period of therapy with cromolyn (abscissa), related to line of identity.
Figure 3. Subjective symptoms and assessment after open trial consisting of eight weeks of therapy with cromolyn (abscissa), related to period of receiving placebo (ordinate).
Figure 4. Pulmonary function after open trial consisting of eight weeks of therapy with cromolyn (abscissa), related to period of receiving placebo (ordinate)