autonomic dysfunction such as tachycardia, hyperthermia, diaphoresis, shivering, blood pressure lability,
and mydriasis; neuromuscular abnormalities such as hyperreflexia, myoclonus, tremor,
and ataxia;
and gastrointestinal symptoms such as abdominal cramping, nausea, vomiting, and diarrhea. Particular caution is advised when increasing the dosages of these agents.