Chest
Volume 109, Issue 2, February 1996, Pages 348-352
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Clinical Investigations: COPD/REHAB
Iodinated Glycerol Has No Effect on Pulmonary Function, Symptom Score, or Sputum Properties in Patients With Stable Chronic Bronchitis

https://doi.org/10.1378/chest.109.2.348Get rights and content

Study objective

It has been reported that therapy with iodinated glycerol (IG) can improve the quality of life for patients with chronic bronchitis. The purpose of this study was to determine the effects of IG therapy on the quality of life, pulmonary function, and on the properties of sputum collected from adults with stable chronic bronchitis.

Design

Thirty-two week, double-blind, randomized, placebo-controlled cross-over study.

Setting

A university outpatient pulmonary clinic.

Participants

Twenty-six adults with stable chronic bronchitis completed the study; 28 completed the first treatment arm.

Interventions

Sixteen weeks each of placebo or IG 60 mg qid.

Measurements

First, pulmonary function by spirometry and plethysmography. Second, symptom score measured using a questionnaire. Third, sputum bulk and surface rheology, spinnability, mucociliary transportability and cough transportability.

Results

There were no significant changes in pulmonary function, clinical scores, or sputum properties related to therapy with IG. There was a significant improvement in the Global Petty score after both IG (p=0.01) and placebo (p<0.01) when compared with baseline, but there was no difference between treatment periods. There was a positive correlation between changes in the Global score during therapy and changes in sputum spinnability (p<0.00l, r=0.38).

Conclusions

This study clearly demonstrates that in chronic bronchitis, 16 weeks of therapy with IG does not produce any appreciable effect on pulmonary function, well being, or on sputum viscoelasticity or clearability.

Section snippets

Study Design

In the previous study6 a significant improvement in well being was demonstrated with IG therapy after 16 weeks. This double-blind, randomized, placebo-controlled, cross-over study is designed to show similar changes after 16 weeks of placebo and IG (30 mg tabs) 60 mg four times daily. The cross-over design has patients serve as their own controls, strengthening the power of the study to detect changes in pulmonary function or sputum properties as a result of therapy.

Patient Selection

Thirty subjects with chronic

RESULTS

Thirty patients were randomized so that half began with the placebo treatment and half with iodinated glycerol therapy. Therapy was crossed over midway through the study. Twenty eight patients completed the iodinated glycerol arm and 26 finished both study arms with complete pulmonary functions recorded and five interval sputum specimens collected. Those who dropped out of the study did so for failure to keep follow up appointments. There were no clinically significant adverse events noted in

DISCUSSION

To our knowledge, this is the first randomized, blinded cross-over trial of a mucoactive agent that simultaneously measured the physical and transport properties of expectorated sputum, pulmonary functions, and well being in patients with chronic bronchitis. In a study of patients with chronic bronchitis taking S-carboxymethylcysteine, an agent thought to reduce sputum viscosity by severing disulfide bonds, Braga and colleagues12 found a reduction in sputum viscosity when patients were on the

ACKNOWLEDGMENT

The authors would like to thank Ms. Titik Dian and John Heller, EE, for help in conducting these studies. We would also like to thank Dr. Jill A. Ohar and Ms. Patricia Dettenmeier, RN, MSN, for providing the sputum specimens from the St. Louis University Pulmonary Clinic.

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Supported by a grant from Wallace Laboratories, Princeton, New Jersey.

revision accepted September 27.

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