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.

[Q]: The patient's blurred vision gradually improved, but visual field defect remained.
[A]: non-adverse drug event


[Q]: CASE SUMMARY: A 66-year-old man with a background history of breast carcinoma was admitted with pleuritic chest pain.
[A]: non-adverse drug event


[Q]: Type II heparin-induced thrombocytopenia (HIT) is an immunological disorder characterized by antibodies to heparin-platelet factor 4 complexes and a high risk of thrombotic complications.
[A]:
adverse drug event