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]: Its treatment is mainly based upon discontinuation of heparin therapy.
[EX A]: non-adverse drug event

[EX Q]: Acute chest pain is a common presentation in emergency.
[EX A]: non-adverse drug event

[EX Q]: A multicentric retrospective pilot study was undertaken to detect GCV-resistance through mutations within the UL97 gene in renal transplant recipients who experienced active HCMV infection and received valacyclovir prophylaxis.
[EX A]:
non-adverse drug event