Theophylline has become an important drug since it has beendiscovered as a main constituent of the tea leaves. Although, a lot ofrecent drugs have been discovered for treatment of obstructive airwaydiseases, theophylline still has important role in the treatment of thesediseases. Theophylline is a xanthine derivative and in overdose, itaffects the central nervous, cardiovascular, and gastrointestinalsystems. Theophylline intoxication has been increased recently due tothe spread of sustained-release formulations.