Theophylline-Induced Alteration in Serum Electrolytes and Uric Acid of Asthmatic Children

Theophylline, (1,3-dimethylxanthine) is widely used as a smooth muscle relaxant, myocardial stimulant and a diuretic agent. The most frequent use of theophylline is in treatment of acute and chronic asthma as a bronchodilator.To determine the effect of Theophylline on serum electrolyte and uric acid, 21 asthmatic children (age range 1,5-7 years) with severe acute asthma and 25 patients with chronic asthma (5-15 years) who were being treated with slow-release theophylline were enrolled in this study. Fifty age and sex matched normal children took part as control. Blood samples (5ml) were withdrawn before, during and after completion of the course of intravenous theophylline treatment (0.05-0.70 mg/kg/ hr). Sera obtained were used for analysis of K+, Na+, phosphorus, calcium and uric acid by RA-1000 automated analyzer and the following results were obtained:(1) After treatment, total serum calcium in acute asthmatic patients decreased significantly compared with controls (P<0.01); (2) serum phosphate and K+ levels of acute and chronic asthmatic patients after therapy decreased as compared with controls (P<0.01). (3) Post therapy increase in serum level of uric acid in acute and chronic asthmatic patients was statistically significant as compared with control (P< 0.001).We conclude that the serum levels of phosphate, potassium, calcium and uric acid should be monitored in patient receiving theophylline especially during prolonged use and critical emergency cases.