It is also noteworthy that the iodinated glycerol- treated patients experienced a reduction in the duration of acute exacerbations. These findings are consistent with other published studies which show that mucolytic therapy reduces both the severity and incidence of acute exacerbations and reduces the number of sick-day leaves in patients with chronic bronchitis.
The purpose of this study was to evaluate objectively the use of symptom assessment in determining the efficacy of mucolytic-expectorant therapy in patients with COPD. The approach used in this study is currently the best available method. Pulmonary function tests were not included as efficacy parameters in this study, although they were used to objectively characterize the patients’ disease upon entry since various studies have shown a weak correlation between the symptoms of chronic airway obstruction and pulmonary function tests. Sputum volume was not considered to be particularly relevant since it tends to increase initially, but can regress before symptomatic improvement becomes apparent. Objective, noninvasive methods for evaluating mucociliary tracheobronchial clearance involving the inhalation of radiolabeled particles are poorly standardized.
Many therapeutic strategies are intended to improve symptoms and the quality of life of patients is a goal which should accompany the improvement of measurements of airflow and volume in patients with COPD. A critical strategy in all stages of disease is smoking cessation, which has been demonstrated to retard the accelerated rate of decline in airflow as judged by FEVj in patients who are susceptible to the damaging effects of cigarette smoking.
Both of these objectives have prompted the development of a number of disease-specific indices for evaluating the effects of treatment on patient well- being. In patients with chronic lung disease, respiratory disease questionnaires are reliable, clinically used tools and can be used in assessing the potential impact of symptoms on the patients quality of life. The frustration and embarrassment associated with coughing and expectoration and the need to use medications in public have been shown to be among the primary emotional problems of patients with COPD. Likewise, dyspnea is one of the most distressing symptoms; it reduces energy, vitality, and tends to produce psychosocial complications. Therefore, in managing patients with chronic airways obstruction, recognition of symptoms as an important guide in managing these patients is essential and these symptoms need to be more closely monitored by physicians treating patients with chronic obstructive pulmonary disease. This study supports the usefulness of objectively evaluating symptoms as a measurement of drug efficacy. Similar to other studies using a small-range scale, score changes indicating highly statistically significant results may be numerically small but represent significant changes in that particular parameter. The precise mechanism of action of iodinated glycerol is not known. Iodinated glycerol is absorbed intact into the blood stream and then metabolized into iodide and glycerol. In man, pharmacokinetic studies show that single doses of iodinated glycerol provide mean peak serum concentrations (C^) of approximately 119 \ig percent iodide and a C^ of approximately 275 \ig percent, following multiple qid doses. A detailed discussion of iodide is contained in a recent review by Ziment. Briefly, iodide appears to be preferentially sequestered into exocrine glands, including bronchial glands, and then secreted along with an augmented output of respiratory tract fluid and mucoprotein; iodide can stimulate gastropulmonary reflex in relatively large doses (0.1 g/kg); iodide has a potent mucolytic action; and since it is an electrolyte, iodide can have a stimulatory effect on ciliary action. canadian pharmacy cialis
In conclusion, this randomized, double-blind, placebo-controlled, multicenter study demonstrated the clinical effectiveness and safety of iodinated glycerol, 60 mg qid, given as adjunctive therapy in a well- defined group of patients with chronic obstructive bronchitis. Iodinated glycerol improved cough symptoms, chest discomfort, mucus clearance, and patient well-being, as well as decreased the duration of acute exacerbation of chronic obstructive bronchitis. This study demonstrated that these symptomatic parameters of efficacy were meaningful indices for evaluating therapy in COPD and that a therapeutic goal of treating patients with COPD should include not only an improvement in pulmonary function indices, but also an improvement in the symptoms associated with COPD.