Dose-ranging study of a new steroid for asthma: mometasone furoate dry powder inhaler

A new formulation of mometasone furoate (MF) for administration by dry powder inhaler (DPI) was evaluated for the treatment of asthma. A 12-week, double-blind, placebo-controlled dose-ranging study compared the efficacy and safety of three doses of MF DPI (100, 200 and 400 mcg b.i.d) with beclomethasone dipropionate (BDP) 168 mcg b.i.d. administered by metered dose inhaler in 365 adult or adolescent patients being treated with inhaled glucocorticoids. The mean change from baseline to endpoint (last treatment visit) for forced expiratory volume in 1 sec (FEV1) was the primary efficacy variable. Secondary efficacy variables included other objective measures of pulmonary function [forced vital capacity (FVC), forced expiratory flow 25-75% (FEV25-75%.) and peak expiratory flow rate (PEFR)] as well as subjective measures of therapeutic response (patients' daily evaluation of asthma symptoms and physicians' evaluation). At endpoint, all four active treatments were significantly more effective than placebo (P < 0.01) in improving FEV1 (MF DPI 5 to 7%, BDP 3%, placebo -6.6%) and all other measures of pulmonary function (FVC: MF DPI 4 to 5%, BDP 2%, placebo -4.7%; FEF25-75%: MF DPI 6 to 18%, BDP 7.5%, placebo -9.5%; PEFR (AM): MF DPI 5 to 10%, BDP 5.7%, placebo -7%). A consistent trend was observed for better improvement in patients treated with MF DPI 200 mcg b.i.d. than with MF DPI 100 mcg b.i.d., with no apparent additional benefit of MF DPI 400 mcg b.i.d. Results for the MF DPI 100 mcg b.i.d. and BDP 168 mcg b.i.d. treatment groups were similar. Patients' and physicians' subjective evaluations of symptoms found similar improvement in the MF DPI 200 and 400 mcg b.i.d. treatment groups, which were slightly better than that in the MF DPI 100 mcg b.i.d. group. Symptoms tended to worsen in the placebo group. MF DPI was well tolerated at all dose levels and the most frequently reported treatment-related adverse effects were headache, pharyngitis and oral candidiasis. No evidence of HPA-axis suppression was detected in any treatment group. In summary, all doses of MF DPI were well tolerated and significantly improved lung function and MF DPI 400 mcg (200 mcg b.i.d.) was the optimal dose in this study of patients with moderate persistent asthma.

Effect of inhaled nitric oxide on pulmonary function in cystic fibrosis

Concentrations of nitric oxide (NO) have been found to be reduced in both the upper and lower airway of patients with cystic fibrosis (CF). As NO modulates bronchomuscular tone, low NO levels may contribute to the obstructive lung disease in these patients. To assess whether increasing inspiratory NO concentrations has any impact on lung function, we have studied 13 CF patients aged 14-38 years in a clinically stable condition and nine healthy controls. NO was applied via a mixing chamber for 5 min with NO concentrations of 100 parts per billion, 1 and 40 parts per million. Spirometry was performed at baseline and after inhalation on each occasion. There were no clinical side-effects at any NO concentration and no changes in oxygen saturation were observed. Lung function remained unchanged in all subjects throughout the study period. Sputum nitrate and nitrite concentrations before and after inhalation of high NO concentrations (40 ppm) in eight CF patients did not show any significant changes, even though a tendency to higher nitrate levels was observed (399 +/- 231 vs. 556 +/- 474 mumol l-1). Therefore, inhaled NO at either the physiological levels present in the upper airway of normal individuals or those used therapeutically to treat pulmonary hypertension has no immediate effect on bronchomuscular tone in patients with cystic fibrosis.

A pilot study on the clinical efficacy of Solanum xanthocarpum and Solanum trilobatum in bronchial asthma

Solanum xanthocarpum and Solanum trilobatum are widely used to treat respiratory diseases in southern Indian traditional medicine (Siddha). A pilot study was undertaken to investigate the clinical efficacy and safety of a single dose of the above herbs in mild to moderate bronchial asthma. The respiratory functions (FVC, FEV1, PEFR and FEF25-75%) were assessed by using a spirometer prior to and 2 h after oral administration of 300 mg powder of whole plant of either S. xanthocarpum or S. trilobatum. Standard bronchodilator drugs, salbutamol (4 mg) and deriphylline (200 mg) were used for comparison. Treatment with either S. xanthocarpum or S. trilobatum significantly improved the various parameters of pulmonary function in asthmatic subjects. However, the effect was less when compared to that of deriphylline or salbutamol. No untoward effects were reported during the study. The results of the present study confirm the traditional claim for the usefulness of these herbs in bronchial asthma. More detailed studies are required to investigate the mechanism of action and therapeutic utility of S. xanthocarpum and S. trilobatum.

Effect of low-dose beclomethasone dipropionate on asthma control and airway inflammation

The effects of usual or low doses of inhaled corticosteroids on airway mucosal inflammation have not yet been examined. We therefore, compared the effects of inhaled beclomethasone dipropionate (BDP) 336 microg x day(-1) on asthma control outcomes and markers of airway inflammation. Twenty-four adult subjects with mild and moderate asthma were randomized to receive either BDP or placebo for four weeks; then subjects entered a single blind four week placebo run-in period. We found that the BDP group had significantly greater improvements in forced expiratory volume in one second (FEV1), morning peak flow, and rescue salbutamol use than the placebo-treated group. The improvement in FEV1 largely reversed one week after treatment was stopped. The decrease in the median percentage of eosinophils in induced sputum in the BDP group from 3.8% to 3.4% was not significant, but because eosinophils increased from 8.4% to 12.7% in the placebo group, there was a significant difference between treatment groups (p=0.03). There was no significant difference between groups during treatment in the levels of eosinophil cationic protein (ECP), tryptase mucin-like glycoprotein, or fibrinogen in induced sputum. The change in FEV1 in the BDP group did not correlate significantly with the change in eosinophil percentage or ECP levels. We concluded that four weeks of treatment with inhaled beclomethasone dipropionate 336 microg x day(-1) was associated with significant improvements in peak flow, forced expiratory volume in one second, and rescue salbutamol use in asthmatic subjects but was not associated with large reductions in markers of eosinophilic inflammation, bronchovascular permeability, or mucus hypersecretion.

Ozone responsiveness in smokers and nonsmokers

Short-term exposure to ozone causes decrements in lung function, but predictors of responsiveness remain largely unknown. Ninety healthy volunteers (56 never-smokers, age [mean +/- SD] 25 +/- 4 yr; 34 current smokers, 13 +/- 9 pack-yr, age 28 +/- 1 yr) were exposed to 0.22 ppm ozone for 4 h, with exercise, in an environmental chamber. We measured spirometry and specific airway conductance before, during, and immediately after exposure, and assessed symptoms by questionnaire. Smokers experienced a smaller increase in respiratory symptoms following exposure to ozone than did nonsmokers. Decrements in FEV1 were significantly less than for smokers than for nonsmokers (p = 0.0013). Ozone responsiveness (> 15% fall in FEV1) occurred in 16 of 56 never-smokers (28.6%) and 4 of 34 smokers (11.8%). Multiple logistic regression analysis found pack-yr of smoking to be associated with decreased ozone responsiveness (odds ratio [OR] 0.87, p = 0.017). Age, gender, and methacholine responsiveness were not predictive of responder status. Fourteen smokers and 25 nonsmokers were subsequently exposed once to air and twice to ozone; smokers as well as nonsmokers were consistent in their subsequent responsiveness (or lack of responsiveness) to ozone. Healthy smokers have smaller decrements in lung function and fewer symptoms in response to ozone exposure than do nonsmokers.

Effects of cigarette smoking on lung function in adolescent boys and girls

BACKGROUND

Little is known about the sex-specific effects of cigarette smoking on the level and growth of lung function in adolescence, when 71 percent of people in the United States who smoke tried their first cigarette.

METHODS

We studied the effects of cigarette smoking on the level and rate of growth of pulmonary function in a cohort of 5158 boys and 4902 girls 10 to 18 years of age, examined annually between 1974 and 1989 in six cities in the United States.

RESULTS

We found a dose-response relation between smoking and lower levels of both the ratio of forced expiratory volume in one second to forced vital capacity (FEB1/FVC) and the forced expiratory flow between 25 and 75 percent of FVC (FEF25-75). Each pack per day of smoking was associated with a 3.2 percent reduction in FEF25-75 for girls (P=0.01) and a 3.5 percent reduction in FEF25-75 for boys (P=0.007). Whereas the FVC level was elevated in smokers, the rate of growth of FVC and FEV1 was reduced. Among adolescents of the same sex, smoking five or more cigarettes a day, as compared with never smoking, was associated with 1.09 percent slower growth of FEV1 per year in girls (95 percent confidence interval 0.70 to 1.47) and 0.20 percent slower growth in boys (95 percent confidence interval, -0.16 to 0.56), and with 1.25 percent slower growth of FEF25-75 per year in girls (95 percent confidence interval 0.38 to 2.13) and 0.93 percent slower growth in boys (95 percent confidence interval, 0.21 to 1.65). Whereas girls who did not smoke reached a plateau of lung function at 17 to 18 years of age, girls of the same age who smoked had a decline of FEV1 and FEF25-75.

CONCLUSION

Cigarette smoking is associated with evidence of mild airway obstruction and slowed growth of lung function in adolescents. Adolescent girls may be more vulnerable than boys to the effects of smoking on the growth of lung function.

Acute safety and effects on mucociliary clearance of aerosolized uridine 5'-triphosphate +/- amiloride in normal human adults

Impaired mucociliary clearance contributes to the pathophysiology of several airways diseases including cystic fibrosis, asthma, and chronic bronchitis. Extracellular triphosphate nucleotides (adenosine 5'-triphosphate [ATP], uridine 5'-triphosphate [UTP]) activate several components of the mucociliary escalator, suggesting they may have potential as therapeutic agents for airways diseases. We conducted initial (Phase I) studies of acute safety and efficacy of aerosolized UTP alone and in combination with aerosolized amiloride, the sodium channel blocker, in normal human volunteers. Safety was assessed by measurement of pulmonary function. Neither UTP alone nor in combination with amiloride caused any clinically significant adverse effects on airway mechanics, (subdivisions of) lung volumes, or gas exchange. Acute efficacy of UTP and amiloride alone and in combination, was assessed by measuring changes in the clearance of inhaled radiolabeled particles. A 2.5-fold increase in mucociliary clearance was seen in response to UTP alone and in combination with amiloride. We conclude that aerosolized UTP +/- amiloride clearly enhances mucociliary clearance without acute adverse effects in normal adults, and may have therapeutic potential to enhance airways clearance in diseases characterized by retained airways secretions.

The effects of albuterol on the lung function of hospitalized patients with cystic fibrosis

Twenty-four hospitalized patients with cystic fibrosis were enrolled into a 2-d, double-blind, placebo-controlled, randomized crossover trial comparing albuterol inhalation aerosol with a saline placebo. Aerosols were administered with the first three of four chest physiotherapy sessions given 4 h apart. Spirometry was measured before and 45 min after 7:00 A.M. and 3:00 P.M. therapy and before therapy at 7:00 P.M. and 7:00 A.M. the next morning. The mean percent change in FVC, FEV1, and FEF25-75% at 7:00 A.M. was 10.7, 14.8, and 19.6% with albuterol versus 2.4, 1.0, and -0.8% with placebo (p = 0.0012, < 0.0001, and = 0.003, respectively). A greater than 8% change in FEV1 separated changes with albuterol versus placebo with 96% specificity and occurred in 75% of all patients with albuterol; 71% at 7:00 A.M. versus 24% at 3:00 P.M. The reduction in response at 3:00 P.M. (p < 0.01) was presumably due to prolonged effects of morning therapy ( > 4 h). Individual changes in spirometry were significantly more positive and homogeneous with albuterol versus placebo at both 7:00 A.M. and 3:00 P.M. The mean percent change for the FVC, FEV1, and FEF25-75 across the day (7:00 A.M. pretherapy to 7:00 P.M. pretherapy) was 8.1, 10.1, and 9.7% with albuterol versus 3.9, 3.5 and 2.6% with placebo (p = 0.029, 0.036, and 0.232, respectively). The more positive and homogeneous changes in spirometry with albuterol, along with greater changes in these measures across the day when compared with placebo, suggest that albuterol improves pulmonary function in a majority of hospitalized patients with cystic fibrosis.

Surfactant nebulization does not alter airflow obstruction and bronchial responsiveness to histamine in asthmatic children

To test the hypothesis that surfactant nebulization improves pulmonary function and reduces bronchial responsiveness to histamine, we studied 12 children with asthma. We measured before and after inhalation of 100 mg nebulized natural-derived bovine surfactant (Alveofact (registered)) and after nebulization of 0.9% NaCl the change in peak expiratory flow, vital VC, FEV1, and forced expiratory flows at 50 and 75% of the flow-volume curve. In addition, we performed a histamine inhalation challenge. We did not find any significant changes in these parameters after nebulization of surfactant. These findings indicate that the inhalation of nebulized surfactant does not alter airflow obstruction and does not alter bronchial responsiveness to histamine in asthmatic children with airflow obstruction.

Are asthma-like symptoms due to bronchial or extrathoracic airway dysfunction?

Patients with asthma-like symptoms may not have asthma but obstruction of the extrathoracic airway (EA). To evaluate if dysfunction of the EA causes asthma-like symptoms, we assessed bronchial and EA responsiveness to inhaled histamine in 441 patients who presented with at least one of three key symptoms--cough, wheeze, dyspnoea--but had neither documented asthma nor bronchial obstruction. The histamine concentrations causing a 20% fall in forced expiratory volume in 1 s (PC20FEV1) and a 25% fall in maximal mid-inspiratory flow (PC25MIF50) were used as respective thresholds of bronchial and EA responsiveness. Values 8 mg/mL or less indicated bronchial (B-HR) or EA hyper-responsiveness (EA-HR). The influence of concurrent upper respiratory tract diseases, such as post-nasal drip (PND), pharyngitis, laryngitis and sinusitis, was also assessed. We found four response patterns to the histamine challenge: EA-HR in 26.5% of the patients, B-HR in 11.1%, combined EA-HR and B-HR in 40.6%, and no-HR in 21.8%. Cough was reported by 79% of the patients, wheeze by 53%, and dyspnoea by 40%. Patients with cough as the sole presenting symptom (34.2%), as compared with those with wheeze and/or dyspnoea (20%), had significantly greater probability of having EA-HR (OR 5.35, 95% CI 3.25-8.82) and lower probability of having B-HR (OR 0.45, CI 0.28-0.70); patients with cough plus wheeze and/or dyspnoea (45.8%) had significantly greater probability of having both EA-HR and B-HR than either those with cough alone (OR 2.48, CI 1.49-4.13), or those with wheeze and/or dyspnoea but not cough (OR 1.74, CI 1.36-2.22). EA-HR alone or combined with B-HR was strongly associated with EA diseases, particularly pharyngitis and PND. Cough was significantly associated with PND, either when it was the sole symptom (OR 2.16, CI 1.14-4.09) or when it was combined with wheeze and/or dyspnoea (OR 3.53, CI 1.97-6.33). Our results suggest that extrathoracic airway dysfunction may account for asthma-like symptoms, particularly chronic cough. This abnormality seems to be sustained by chronic diseases of the upper respiratory tract.

Comparison of the bronchodilatory effects of cetirizine, albuterol, and both together versus placebo in patients with mild-to-moderate asthma

BACKGROUND

Many potential users of the H1 antihistamine cetirizine are asthmatic and may be using inhaled albuterol. This study was conducted to assess the possible bronchodilatory effect of cetirizine in patients with mild-to-moderate asthma and to determine whether cetirizine interacts with albuterol.

METHODS

In a randomized, double-blind, placebo-controlled, crossover study, the effects on pulmonary function of 5, 10, and 20 mg oral doses of cetirizine with and without inhaled albuterol (180 micrograms) were determined in 12 patients at 11 time points over 8 hours. The primary measure of efficacy was forced expiratory volume in 1 second (FEV1).

RESULTS

Cetirizine with or without albuterol significantly increased FEV1, peak expiratory flow rate, and forced expiratory flow rate between 25% and 75% of vital capacity relative to baseline and placebo but did not have a significant effect on forced vital capacity. The effect of 20 mg of cetirizine on FEV1 was generally greater than that of 10 or 5 mg, but the difference was statistically significant only at the 30-minute time point (p < 0.05). All three cetirizine doses produced significantly greater increases than placebo in FEV1 and forced expiratory flow rate between 25% and 75% of vital capacity for 8 hours and in peak expiratory flow rate for 7 hours (p < 0.02). Albuterol alone had a significant effect on the four pulmonary function variables from 1 to 5 hours after baseline (p < 0.05), which is consistent with albuterol's recommended dosing frequency of every 4 to 6 hours. Albuterol alone increased FEV1 significantly more than 5 mg of cetirizine alone but not 10 mg or 20 mg of cetirizine alone at 60, 90, and 120 minutes after baseline, but all three doses of cetirizine increased FEV1 significantly more than albuterol 7 and 8 hours after baseline (p < 0.05), indicating that the bronchodilatory action of cetirizine lasts longer than that of albuterol. Cetirizine neither potentiated nor inhibited the bronchodilatory action of albuterol, but the two drugs appeared to have an additive bronchodilatory effect. None of the cetirizine treatments caused a worsening of pulmonary function, and all were well tolerated.

CONCLUSIONS

Cetirizine has a significant bronchodilatory effect in patients with mild-to-moderate asthma and can be used to treat concomitant conditions (e.g., allergic rhinitis) without concern that it will interfere with the bronchodilatory effect of albuterol or cause worsening of asthma by itself.

Response to acute ozone exposure in healthy men. Results of a screening procedure

We screened 64 healthy, nonsmoking men, 18 to 35 yr old, for their sensitivity to 0.35 ppm ozone (O3) administered for 130 to 150 min with intermittent exercise. The changes in FVC, FEV1, AND FEF25-75 (p < 0.0001) immediately after O3 exposure varied widely among subjects. Histograms of the percentage changes in FVC and FEV1 did not differ from a unimodal, skewed (gamma) distribution (p = 0.99 and p = 0.17, respectively); the changes in FEF25-75 tended to deviate from a gamma distribution (p = 0.055). To adjust FEF25-75 for the confounding effects of O3 on FVC, we used multiple linear regression analysis with contemporaneous FVC as a covariable, analysis of a subgroup of nine subjects whose O3-induced FVC changes were < or = 5%, and volume correction of FEF25-75 for any changes in FVC after exposure. These analyses showed reductions in FEF25-75 unexplained by and following a different time course than the O3-induced changes in FVC. In 26 subjects also exposed to filtered air, significant effects of O3 on respiratory frequency (p < 0.004) and tidal volume (p < 0.0007) correlated weakly with FVC changes. The results confirm the wide variability in spirometric responsiveness among individuals to O3 and suggest that intrinsic narrowing of the small airways may be a significant component of the functional response.

Formaldehyde exposure, acute pulmonary response, and exposure control options in a gross anatomy laboratory

Formaldehyde exposure, acute pulmonary response, and exposure control options were evaluated in a group of 34 workers in a gross anatomy laboratory. Time-weighted average (TWA) exposure to formaldehyde ranged from 0.07-2.94 parts per million (ppm) during dissecting operations. More than 94% were exposed to formaldehyde in excess of the ceiling value of 0.3 ppm recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). The eight-hour TWA exposure of 31.7% of the subjects exceeded the action level of 0.5 ppm set by the Occupational Safety and Health Administration (OSHA). Reported symptoms included irritation of eye (88%), nose (74%), throat (29%), and airways (21%). Forced vital capacity (FVC) and forced expiratory volume in 3 seconds (FEV3) decreased, and FEV1/FVC increased during the exposure. The changes of FEV3 were statistically different from those of the controls. The results strongly support the necessity for designing and testing special local exhaust-ventilated worktables with necessary flexibility for dissecting operations.

In chronic obstructive pulmonary disease, a combination of ipratropium and albuterol is more effective than either agent alone. An 85-day multicenter trial. COMBIVENT Inhalation Aerosol Study Group

Combination bronchodilator therapy for chronic obstructive pulmonary disease (COPD) is available widely throughout the world except in North America. Previous studies have yielded conflicting results regarding the advantages of combining anticholinergic therapy with sympathomimetic therapy in COPD. We report the results of a 12-week prospective, double-blind, parallel-group evaluation of the use of the following: albuterol, a beta-adrenergic agent; ipratropium, an anticholinergic agent; or a combination of the two, administered by metered-dose inhaler to patients with moderately severe stable COPD. Following baseline studies, 534 patients were given one of the three test bronchodilator preparations to be used at home four times daily in addition to oral theophylline and corticosteroids as required. The doses of the latter two drugs were kept stable. Subjects were tested on days 1, 29, 57, and 85. Analysis of 1-s forced expiratory volume (FEV1) curves on those test days indicated that the combination was superior to either single agent alone in peak effect, in the effect during the first 4 h after dosing, and in the total area under the curve of the FEV1 response. The mean peak percent increases in FEV1 over baseline on the four test days were 31 to 33 percent for the combination, 24 to 25 percent for ipratropium, and 24 to 27 percent for albuterol. The differences between the combination and its components were statistically significant on all test days. The AUC0-4 means for the combination were 21 to 44 percent greater than the ipratropium means and 30 to 46 percent greater than the albuterol means. Similar changes were noted in the forced vital capacity curves. Symptom scores did not change over time and did not differ among the treatment groups. We conclude that the combination of ipratropium and albuterol, when given by metered-dose inhaler to patients with COPD, is more effective than either of the two agents alone. The advantage of the combination is apparent primarily during the first 4 h after administration. The availability of combination therapy by metered-dose inhaler should help to improve patient compliance.

Utility of inhaled pentamidine prophylaxis in lung transplant recipients

The incidence of Pneumocystis carinii pneumonia (PCP) has been shown to be high posttransplantation in the absence of prophylaxis. For this reason, lung transplant recipients routinely receive prophylaxis. We report on our results using aerosolized pentamidine prophylaxis in nine patients post-lung transplantation (eight single lung transplants, one double). The patients received monthly treatments of 300 mg of aerosolized pentamidine for a mean of 10.6 months (range, 4 to 21 months). Patients were routinely monitored with serial pulmonary function studies and bronchoscopy as clinically indicated. Two of the patients experienced bronchospasm in response to the therapy. None of the patients experienced any episodes of PCP during the period of inhaled pentamidine prophylaxis. Inhaled pentamidine is a safe and effective form of PCP prophylaxis and may be used instead of sulfamethoxazole-trimethoprim in patients who have a sulfa allergy or other untoward sulfa side effects.

Unspecific bronchial reactivity to carbachol in healthy subjects--effect of age and smoking habits

Chronic inflammatory processes of the airways induced by long-time cigarette consumption are a crucial factor in the pathogenesis of chronic obstructive pulmonary disease. In contrast, the role of cigarette smoking in the pathogenesis of bronchial hyperreactivity (BHR) is still unclear. The aim of this study was to assess the effect of chronic cigarette consumption on pulmonary function tests and BHR in healthy subjects. 63 healthy smokers and 63 lifetime nonsmokers matched for sex, age, height and weight were evaluated. Pulmonary function was determined by body plethysmography and spirometry. Bronchial provocation was performed by inhalation of increasing doses of carbachol (up to 25 g/l) in isotonic NaCl solution. Pulmonary function tests were within normal limits in all subjects. Nevertheless, midexpiratory flow at 25% of forced vital capacity was significantly smaller, and functional residual capacity was significantly greater in middle-aged smokers (age: 40-60 years) compared to middle-aged nonsmokers (p < 0.05, both comparisons). In young smokers and nonsmokers (age: 20-30 years) pulmonary function tests were not different (p > 0.28, all comparisons). Importantly, the carbachol concentration that provoked a 50% rise in specific airway resistance (PD50sRaw) was similar in smokers and nonsmokers of both age groups (p > 0.05, both comparisons) and did not correlate with the age of the subjects (p > 0.2). No correlations between baseline values of pulmonary function tests and PD50sRaw were observed (p > 0.34, all comparisons). The observations confirm that the distribution profile of BHR is unimodal and apparently not affected by age and smoking habits.

Pulmonary function in symptom-free asthmatics

Seventy-five adult asthmatic patients with clinical remission underwent spirometry. Only 8.3% of the subjects demonstrated normal spirometry. The others had reduced vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), maximum mid-expiratory flow rate (MMF) and peak flow rate (PEFR). This study demonstrates that asthma can cause irreversible airflow obstruction and there is a poor relationship between symptoms in asthmatics and their respiratory function test results.

[The bronchodilator agent, Ventodisk, in the powdered inhalation form without freon is better]

The authors compared the effectiveness and advantages of the powdered inhalation variety of the preparation Ventodisc (Glaxo) with the "classical" dosed inhalation form of Salbutamol (Polfa) in 21 patients with bronchial asthma. During administration of 0.2 mg of the two drugs various conditions (mastering of the inhalation technique, elimination of the action of other drugs and the same time of day when the drug was administered) was respected. Values of ventilation parameters of the central and peripheral respiratory pathways before administration of the drugs did not differ significantly. The powdered form of salbutamol--Ventodisc (Glaxo) had a greater dilatating action than the classical dosed aerosol form--Salbutamol (Polfa) because: 1. in FEV1 values between rest and Ventodisc (1.47 l and 1.73 l) differed significantly, however, after subsequent inhalation of Salbutamol no further significant improvement occurred (1.79 l); 2. when the sequence of stimuli was reversed a significant increase of the FEV1; value occurred after Salbutamol (from 1.50 l to 1.67 l, p < 0.004) but Ventodisc caused a further significant increase (p < 0.0006). The tolerance of both drugs was equal. The powdered inhalation form of Salbutamol (Ventodisc--Glaxo) was better than the "classical" dosed aerosol form of salbutamol (Salbutamol--Polfa) as it had a greater dilatating effect in the central airways and moreover did not contaminate the environment.

Effects of aerosol methacholine and histamine on airways and lung parenchyma in healthy humans

To investigate whether histamine (His) and methacholine (MCh) have different effects on airways and lung parenchyma, 11 healthy subjects were given aerosol MCh until a response plateau was obtained and then two doses of His. At the plateau, forced expiratory volume in 1 s and forced expiratory flow at 40% of vital capacity from partial flow-volume curves were reduced by 19 +/- 3 (SE) and 80 +/- 4%, respectively. Aerosol His decreased forced expiratory volume in 1 s by an additional 12 +/- 1% but left partial forced expiratory flow unchanged. The bronchodilator effect of deep inhalation, as inferred from the ratio of forced expiratory flow from maximal to that from partial flow-volume curves, increased after MCh and plateaued but decreased after His. Quasi-static transpulmonary pressure-volume area determined in seven subjects was unchanged after MCh but was increased by 57 +/- 10% after His. We conclude that adding His after the response to MCh plateaued does not increase the maximal degree of bronchoconstriction but may increase parenchymal hysteresis, thus blunting the bronchodilator effect of deep inhalation. These results suggest that His and MCh have similar effects on airway smooth muscle but different effects on lung tissue properties.

Intrathecal morphine during thoracotomy, Part II: Effect on postoperative meperidine requirements and pulmonary function tests

The ability of intrathecal morphine (ITM) to reduce post-thoracotomy pain and meperidine requirements was investigated. Thirty adult patients scheduled for thoracic surgery were studied. Following induction with thiamylal sodium and succinylcholine, anesthesia was maintained with 100 micrograms of fentanyl, vecuronium, and enflurane. Prior to skin incision, 16 patients received intrathecal morphine, 12 micrograms/kg, injected at the L3-4 or L4-5 level. The other 14 patients were controls. Postoperatively, patients were evaluated for pain scores and the total doses of meperidine required over 24 hours. The patients in the ITM group required significantly less meperidine compared to the control group (59 +/- 68 v 167 +/- 97 mg, respectively) and had lower pain scores (1.4 +/- 1.1 v 2.4 +/- 0.9 mg, respectively). There were no serious side effects attributable to ITM. It is concluded that ITM is an effective adjunctive treatment for control of post-thoracotomy pain.

Preliminary study on the effect of broxaterol on bronchial hyperresponsiveness in asthmatic children: influence of allergen exposure

Increased bronchial hyperresponsiveness (BHR) has been reported in adult asthmatic patients after regular treatment with beta 2-agonists. In this study we evaluated the effect of a 4-weeks treatment period with broxaterol, a new beta 2-agonist, on BHR in asthmatic children living in two different environmental conditions. Two groups of patients, 24 domiciled at sea level, allergen exposed (group 1), and 24 resident at high altitude (Misurina, 1,756 m) in an allergen-free environment (group 2), have been tested. Children were randomly treated with broxaterol 400 micrograms q.i.d. or sodium chromoglycate 10 mg q.i.d. (as control treatment) by the metered dose inhaler for 4 weeks. Pulmonary function tests and methacholine challenge were performed at the beginning and at the end of the study. Throughout the study period a diary card was completed and peak expiratory flow rate (PEFR) was measured three times daily. Forty-two of the patients admitted concluded the study. No significant change was observed in the methacholine PC20 throughout the study period regardless of the type of treatment and/or environment. The amplitude percentage mean of diurnal changes in PEFR during the study period showed no statistically significant differences between treatments or centres, or in the interaction of treatment with centre, time with treatment, time with centre, time with centre and treatment (p > 0.05). Therefore in this pilot study regular treatment with broxaterol for 4 weeks did not cause an increase in BHR in asthmatic children both in conditions of allergen exposure and in an environment free of offending allergens.

Effects of steady-state and variable ozone concentration profiles on pulmonary function

Measurements of ambient ozone (O2) concentration during daylight hours have shown a spectrum of concentration profiles, from a relatively stable to a variable pattern usually reaching a peak level in the early afternoon. Several recent studies have suggested that in estimating exposure dose (O3 concentration [C] x exposure time [T] x ventilation [V]), O3 concentration needs to be weighted more heavily than either ventilation or duration of exposure in the estimates. In this study we tested the hypothesis that regardless of concentration pattern and exposure rate the same exposure dose of O3 will induce the same spirometric response. We exposed 23 healthy male volunteers (20 to 35 yr of age) for 8 h to air, 0.12 ppm O3 (steady-state), and a triangular exposure pattern (concentration increased steadily from zero to 0.24 ppm over the first 4 h and decreased back to zero by 8 h). During the first 30 min of each hour, subjects exercised for 30 min at minute ventilation (VE) approximately 40 L/min. The order of the exposures was randomized, and the exposures were separated by at least 7 days. The response patterns over the 8-h periods for spirometric variables in both O3 exposures were statistically different from air exposure changes and from each other. For FEV1 the p values were 0.017 between air and steady-state profile, 0.002 between air and triangular profile, and 0.037 between steady-state and triangular profiles. Although in the triangular pattern of exposure the maximal O3 concentration was reached at 4 h, the maximum FEV1 decrement (10.2%) was observed at 6 h of exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between nonspecific bronchial responsiveness to methacholine and peripheral mononuclear leukocyte beta-adrenergic receptor function in young drug-naive subjects

Asthma is associated with dysfunction of the beta-adrenergic receptor adenylyl cyclase signal transduction pathway. It has been argued that this results from receptor down-regulation by beta-agonist therapy. This study examined the relationship between nonspecific bronchial responsiveness (NSBR) to methacholine (Newcastle dosimeter method) and beta-adrenergic receptor density (Bmax) and affinity (%KH) in membranes from peripheral blood mononuclear leukocytes (MNL) in 12 male (27.3 +/- 1.7 yr old) and 14 female (31.4 +/- 1.7 yr old) drug-naive subjects with and without symptoms of mild intermittent wheezing. None had ever smoked or received any antiasthma medication. "Hyperresponsive" subjects were defined as those (n = 11) whose simplified slope of FEF50 (calculated as the percent fall in FEF50 divided by the dose of methacholine) was more than one SD above the mean for asymptomatic subjects. The log of the slope was reproducible (repeatability coefficient = 0.43) on two nonconsecutive days. Multiple regression analysis (overall R2 = 0.57) revealed negative relationships between the log of the slope and both Bmax (p = 0.016) and %KH (p = 0.011). Analysis of variance confirmed a lower mean (+/- SEM) value of %KH in "hyperresponsives" (45.7 +/- 5.5%) than in "normoresponsives" (60.4 +/- 4.1%, p = 0.04) with a similar trend for Bmax (hyperresponsives = 33.5 +/- 4.1 fmol/mg, normoresponsives = 45.9 +/- 7.1 fmol/mg, p = 0.18). These relationships between bronchial responsiveness, Bmax, and %KH cannot be explained by drug therapy, and they provide further evidence that there is an intrinsic impairment in the function of beta-adrenergic receptors on peripheral MNLs from subjects with high levels of nonspecific bronchial responsiveness.

Effect of age on bronchodilator response

STUDY OBJECTIVE

Our objective was to compare the differential effects of age and drug type on bronchodilator response.

DESIGN

The design was an unblinded, randomized crossover study.

SETTING

An ambulatory pulmonary drug study unit was the setting.

PATIENTS

Nineteen young (18 to 25 yr) and 17 elderly (greater than 65 yr) stable asthmatic subjects were studied.

INTERVENTIONS AND MEASUREMENTS

Albuterol or ipratropium was given on two separate mornings using an MDI with extender. Subjects inhaled two puffs initially and then one puff every 30 min to a total of six puffs. Pulmonary function, blood pressure, and pulse were measured at baseline and every 30 min for 3 h.

RESULTS

All subjects had a greater than 15 percent increase in FEV1 with one or both drugs. More patients responded to albuterol than to ipratropium in both age groups. The maximum percentage of change from baseline was greater (p less than 0.05) with albuterol (mean, 40.1 percent in young and 60.5 percent in old) than with ipratropium (21.2 percent in young; 31.2 percent in old) in both groups. These differences remain significant after correction for baseline differences using area-under-the-curve analysis of the percent of maximum improvement; however, the differences between age groups for the same drug were not statistically significant by either index of change. There were also no differences between drugs or between age groups for time (or number of puffs) to reach maximum improvement (mean, 2.0 to 2.2 h for albuterol and 1.6 to 1.7 h for ipratropium). The changes in FVC and FEF25-75% were similar to FEV1. Changes in blood pressure and pulse were not significant. Three subjects stopped therapy with albuterol with side effects.

CONCLUSIONS

Both drugs are effective bronchodilators in young and old asthmatic subjects, but albuterol results in a greater magnitude of response in both age groups. Age is not a predictor of response to either drug.