Final answer:
The earliest sign of phenytoin toxicity is the presence of nystagmus on far lateral gaze. Some other effects include blurred vision, diplopia, ataxia, slurred speech, dizziness, drowsiness, lethargy, and decreased mentation, which progresses to coma. The first step in the management of side effects due to higher drug levels is to reduce or adjust the dosage.
Step-by-step explanation:
It is the first indication of phenytoin toxicity when nystagmus appears on far lateral gaze. Other side effects include diplopia, ataxia, slurred speech, lethargy, dizziness, and reduced mentation, which might lead to a coma. Lowering or modifying the dosage is the primary line of treatment for negative effects brought on by increased medication levels.
Handling certain symptoms and keeping an eye on the drug schedule are essential for controlling phenytoin toxicity. Prompt intervention and vigilant medical oversight aid in averting additional difficulties and guarantee the secure administration of antiepileptic drugs such as phenytoin.