Abstract
The purpose of this study is to investigate the clearance of theophylline (THCL) by specific factors which could affect THCL including smoking, concurrent drug use, and congestive heart failure (CHF), in pneumoconiosis outpatients over the age of 59, as well as the relationship between THCL and the values of respiratory function tests.
The subject population, which consisted of patients who were administered theophyllines, consisted of a smoking group, a concurrent drug use (certain drugs decreasing THCL on packageinsert drug information) group, a CHF group, and a control group.
The results of our analysis showed the THCL level in the smoking group to be significantly higher than that in the other groups (p<0.05). The THCL level also showed a significantly positive correlation with the % vital capacity (%VC) (r=0.668, p<0.05) and forced expiratory volume at 1 second (r=0.521.n.s).
The main finding of this study is that smoking was closely related to THCL in pneumoconiosis patients, and smoking induced a theophylline matabolism even in the elderly. The respiratory function correlated positively with THCL. Moreover, the %VC was also suggested to be useful for the THCL variability index.
