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.

Example Input: After ruling out a hydrotelluric source of fluorine, the patient's fluorosis was linked to chronic use of niflumic acid, following the publication in 1978 of the 2 previously reported cases affected by this drug.
Example Output: adverse drug event

Example Input: A patient developed restless legs symptoms paralleling the course of interferon-alpha (IFN alpha) therapy for chronic hepatitis C.
Example Output: adverse drug event

Example Input: However, a large case-control study included three cases of either Stevens-Johnson syndrome or toxic epidermal necrolysis associated with ofloxacin use, but no details of the cases were given.
Example Output:
adverse drug event