Theophylline is widely used for the treatment of chronic asthma. The therapeutic serum concentrations of theophylline
(10 to 20 mg/L) correlate well with the desired biologic effects. The incidence of toxic effects increases notably at serum
concentrations exceeding 20 mg/L (1). The early signs of toxic effects, nausea and vomiting, may be misdiagnosed as
evidence of gastrointestinal abnormality, while later, more severe symptoms, such as seizures and cardiac arrhythmias, may be
attributed to cardiovascular or neurologic abnormalities. Hence, ascertaining an immediate diagnosis in cases of theophylline
toxicity at the emergency department is a very challenging endeavor, especially when the patient presents with altered mental
status.