<prompt> All adverse effects of theophylline are mediated by A1, receptor except:Cardiac arrhythmiasDieresisSeizuresGI discomfo  <response>: Theophylline exes its bronchodilation effect by PDE inhibition effect and Adenosine A1 antagonism. It has multiple side effect : Nausea and vomiting PDE inhibition Headache PDE inhibition Gastric discomfo PDE inhibition Diuresis Adenosine A1 antagonism Arrythmias PDE inhibition, A 1 antagonism Seizures Adenosine A1 antagonism 