title: Reliability of salivary theophylline as a guide to plasma theophylline levels.
abstract: Simultaneous saliva and plasma theophylline levels in 12 chronic asthmatic children were measured by high pressure liquid chromatography following administration of a theophylline preparation. In five subjects, simultaneous plasma and salivary theophylline were measured one week later. A strongly positive correlation between plasma and salivary theophylline levels was found at all time periods tested. There was no substantial difference in the plasma-saliva theophylline ratio determined one week later. A predicted plasma level was compared with the observed value. The proportionality of predicted to observed plasma theophylline levels using either the entire study group mean plasma-saliva ratio or each individual's ratio was approximately 1.00 with 9% variability. When a previously reported plasma-saliva theophylline ratio was used for comparison, the predicted plasma theophylline was 15% above the observed plasma level.
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000097:blood / Q000188:drug therapy; D002648:Child; D002853:Chromatography, Liquid; D002908:Chronic Disease; D006801:Humans; D012463:Saliva / Q000032:analysis / Q000378:metabolism*; D013806:Theophylline / Q000097:blood* / Q000378:metabolism* / Q000627:therapeutic use
chemical_list: D013806:Theophylline