“CNS (headache, insomnia, seizures),GI (n/v)Cardiac (arrhythmia)” June 22, 2017 mfadmin Medicine Average Rating 0 out of 5 stars. 0 votes.You must log in to submit a review. “CNS (headache, insomnia, seizures),GI (n/v)Cardiac (arrhythmia)” theophylline toxicity