Dilantin (phenytoin) is a prescription anticonvulsant medication used for the treatment and prevention of certain types of seizures (abnormal body convulsions), such as those that occur due to epilepsy---a condition that causes repeated seizures. This medication decreases the amount of abnormal electrical signaling in the brain, helping to control involuntary muscle convulsions. If you have any concerns regarding the adverse effects of Dilantin, speak with your doctor prior to beginning treatment with this medication.
Difficulty Sleeping
One of the most common adverse effects associated with Dilantin use is difficulty sleeping. After taking a dose of this medication, you can begin to feel abnormally tired or fatigued. If this occurs, you may experience difficulty remaining focused while at work or school. Certain people may find it difficult to fall asleep or stay asleep---a condition called insomnia. Insomnia can cause extensive daytime fatigue, which can also impact your ability to concentrate and remain alert throughout the day.
Dizziness
Treatment with Dilantin can cause patients to experience episodes of dizziness as an adverse effect of this medication, explain health professionals at Drugs, an informational website that provides peer-reviewed data on currently marketed drugs. Dizziness or lightheadedness can make standing or walking challenging for certain people. Adverse effects of dizziness can be most apparent upon standing or sitting up quickly. If you experience an episode of lightheadedness after taking a dose of Dilantin, sit down until this sensation passes in order to prevent injury from tripping or falling.
Headache
You can experience a headache after taking a dose of Dilantin. Painful headache symptoms are typically mild to moderate in severity and can occur within any region of your head. The severity of headache adverse effects tends to diminish with recurrent use of this medication.
Stomach Upset
While receiving treatment with Dilantin, you can experience stomach upset as an adverse effect of this medication. Common stomach-related adverse events include nausea, vomiting or constipation. Additional side effects associated with these adverse events include abdominal pain, cramping or bloating.
Cognitive Impairment
During treatment with Dilantin, you can also experience cognitive changes, which can include poor memory, decreased motor coordination, confusion, slurred speech or slowed thinking. These adverse effects can significantly impact your ability to work and communicate with other people. Typically, such adverse effects are temporary and will subside progressively as you continue to use this medication.
