instruction:
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.
question:
A 64 year old man with recurrent metastatic squamous cell carcinoma of the head and neck developed severe skin rash and bone marrow aplasia 4 and 7 days, respectively, following a single dose of 40 mg/m2 methotrexate (MTX).
answer:
adverse drug event


question:
Severely elevated serum lithium levels were found.
answer:
non-adverse drug event


question:
After an interval of 3 months, he presented a complex pattern of nail hyperpigmentation, from combined dense horizontal and longitudinal streaks in some nails to diffuse black discoloration in others (Figure).
answer:

non-adverse drug event