Adverse drug reactions are appreciably harmful or unpleasant reactions resulting from an intervention related to the use of medical products, which predicts hazard from future administration and warrants prevention or specific treatment, or alteration of the dosage regimen, or withdrawal of the product. Given medical case reports extracted from MEDLINE, the task is to classify whether the case report mentions the presence of any adverse drug reaction. Classify your answers into non-adverse drug event and adverse drug event.

[EX Q]: Isoniazid inhibits the conversion of tryptophan to niacin and may induce pellagra, particularly in poorly nourished patients.
[EX A]: adverse drug event

[EX Q]: All patients except two had new recurrences within the observation time.
[EX A]: non-adverse drug event

[EX Q]: Significant clinical improvement of the porphyria followed withdrawal of the diphenylhydantoin.
[EX A]:
adverse drug event