1202
Attempts were made to stop and then restart the theophylline therapy at progressively lower doses; however, with each attempt, the patient's reaction to the drug became more toxic, with serum theophylline levels ranging between 99.9 and 149.9 micromol/L (18 and 27 microg/mL).
 adverse event: became 
Please tell me event type and its trigger word from given type options. Output format is "type: trigger".  Option: adverse event, potential therapeutic event 
Text: {0} 
Answer:
 adverse event: became 