Wiki Adverse reaction

[PatWillis]

Dilantin toxicity resulting in nystagmus is this considered an adverse effect

 

[wbrodsky]

Dilantin toxicity resulting in nystagmus is this considered an adverse effect

This is actually a known side effect of the drug. According to drugs.com, it is a very common one, too. So yes, I would say this is an adverse effect as opposed to a poisoning.