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: Since the thrombocyte count started to increase immediately after initiation and dropped immediately after discontinuation of ciprofloxacin and tazobactam/piperacillin and all other drugs were discontinued already before or were started after the nadir of the thrombocyte count, these two antibiotics were regarded causative.
A: 
adverse drug event