Mood Changes

• Because seizure medications are aimed at altering brain chemistry, a common side effect is mood and/or behavior changes. These include depression, anxiety, hostility, restlessness, hyperactivity and slurred speech.
  
  

Stevens Johnson Syndrome

• Although rare, one of the potential serious side effects is Stevens Johnson Syndrome, which is characterized by peeling skin, rashes, sores and swollen epidermis. It can be mistaken for an allergic reaction and if left untreated can eventually lead to death.
  
  

Severe Side Effects

• Other serious side effects include swollen glands, nausea, loss of balance, stomach pain, bruising, changes in face shape and tender gums. These types of adverse events should be reported to your physician immediately to evaluate drug usage and dosing requirements specifically for you.
  
  

Mild Side Effects

• Some of the less serious side effects of taking Dilantin include mild skin rashes and itching, dizziness, sleeping problems, twitching, nausea or constipation, headaches and joint pain. While these symptoms should be reported to your physician, they are less severe and an emergency appointment is not always necessary.
  
  

Allergic Reactions

• Differentiating between mild side effects and allergic reactions is important. Symptoms of an allergic reaction include hives, swelling and difficulty breathing. If an allergic reaction occurs, it is important to report the event to your physician and the Food and Drug Administration for monitoring purposes.