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.
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Question: Anti-tuberculous drugs had been stopped on the 2nd day of therapy due to development of optic neuritis secondary to ethambutol administration at another hospital.

Answer: adverse drug event


Question: A young patient experienced marked sinus tachycardia while smoking marijuana and receiving therapeutic doses of nortriptyline.

Answer: adverse drug event


Question: CONCLUSIONS: This is the second case report that describes gemcitabine-induced radiation recall in rectus abdominus muscles after gemcitabine-based radiation therapy.

Answer:
adverse drug event