Airway Function In Patients Research Articles

Long-and short-acting beta 2-adrenergic agonists. Effects on airway function in patients with asthma

Long-and short-acting beta 2-adrenergic agonists. Effects on airway function in patients with asthma

THE EFFECT OF INHIBITION OF 5-LIPOXYGENASE BY ZILEUTON IN MILD TO MODERATE ASTHMA

Zileuton, a drug that inhibits the action of 5-lipoxygenase can decrease symptoms, bronchodilator use, and improve airway function in patients with mild to moderate asthma. Dosing regimens associated with greater inhibition of leukotriene production were also associated with greater improvement (ie, 600 mg four times a day or 2.4g/day). These findings support the role of leukotrienes in the pathogenesis of asthma and suggest that agents modulating their formation or activity may be of therapeuutic benefit in mild to moderate asthma.

Effects of the mixed phosphodiesterase III/IV inhibitor, zardaverine, on airway function in patients with chronic airflow obstruction

Zardaverine is a selective inhibitor of phosphodiesterase (PDE) III and IV isozymes. It has been shown to exert potent bronchodilator effects in animals. In order to study the efficacy and safety in man, a phase II clinical trial in 10 patients with partially reversible chronic airflow obstruction was carried out. The trial was designed as a double-blind, randomized, five-period change-over study. Zardaverine (at single doses of 1·5 mg, 3·0 mg, or 6·0 mg), salbutamol (0·3 mg) and placebo were administered by metered dose inhaler on separate days. As evaluated by spirometry over a time period of 4 h, salbutamol induced a significant bronchodilatation. In contrast, zardaverine did not improve airway function in these patients. Unwanted effects of the study medication were not observed.

Airway Physiology

The understanding of the mechanisms of dog and cat airway disease is in its infancy, because the clinical tools necessary to measure airway function in patients have not been readily available. The advent of lung function computers that can rapidly analyze flow-volume loops and calculate Cdyn and RL will make it easier to evaluate airway function in disease and to detect the effects of the newer specific receptor blockers. In the not-too-distant future, measurements of lung function will be used to prove the efficacy of new therapeutic agents for canine and feline airway disease and to guide the clinician in the use of these agents.

Effects of Esmolol on Airway Function in Patients with Asthma

In a double-blind, randomized, crossover study in ten patients with asthma, the effects on specific airway resistance of esmolol, a new ultra-short-acting beta 1-selective adrenoceptor blocker, were compared with those of placebo. Specific airway resistance was measured during increasing doses of esmolol infusion, during dry air provocation tests, and following isoproterenol inhalation. These same studies were later carried out on six of ten patients following intravenous propranolol infusion. All patients were able to tolerate the maximum dose of esmolol (300 micrograms/kg/min); treatment differences between esmolol and placebo were not found. In contrast, intravenous propranolol produced marked symptomatic bronchoconstriction after the lowest dose (1 mg) in two of six patients. Esmolol produced slight but statistically significant enhancement of patients' sensitivity to dry air provocation. Similarly, a slight but significant inhibition of bronchomotor sensitivity to isoproterenol was noted during esmolol infusion. After infusion of 5 mg of intravenous propranolol, one of four patients had a clinically significant increase in sensitivity to dry air. It is concluded that esmolol, because of its short duration of action and relative lack of effect on airway resistance, may be preferred over propranolol in patients with asthma who require treatment with an intravenous beta-blocking agent.