The most common side effects are neurotoxic and dose-related. These include:sedation , impaired memory ,decreased coordination ,dizziness
,slurred speech ,confusion and even headache
If these problems do not diminish within several days, a reduction in the dose of phenytoin
often will solve the problem. Problems with sedation also may be helped by splitting the dose or giving the largest dose at bedtime.
Request that you consult your physician and look into the dose adjustment or withdrawal of the drug