Serious Brain Side Effects of Dilantin

Epilepsy patients who take the drug Dilantin to control seizures could experience a variety of side effects, including atrophy of the cerebellum, an area of the brain important to the control of movement and coordination.

Posture, balance, coordination and speech can all be affected. Someone experiencing cerebellar atrophy might have a swaying or stumbling walk, even appearing to be drunk.


Dilantin (phenytoin) has proven effective in controlling seizures for many people. The drug is also prescribed off-label for conditions including bipolar disorder, anxiety, depression, and attention deficit hyperactivity disorder (ADHD).

Dilantin can accumulate in the cerebral cortex—the brain area that plays a key role in memory, attention, perception, awareness, thought, language and consciousness. The Dilantin accumulation can cause atrophy of the cerebellum, the shrinking and loss of neurons and neuronal connections in the cerebellum. The degree of toxicity is related to the length of time the person has been taking Dilantin and not to the dosage of the medication.

The personal injury attorneys at Parker Waichman stay abreast of the research on Dilantin side effects and they are available to answer questions about filing a Dilantin side effects lawsuit.

Cerebellar atrophy symptoms can include:

  • uncoordinated movements of the limbs or trunk
  • clumsiness with daily activities
  • difficulty walking (unsteadiness)
  • slurred speech
  • visual complaints
  • abnormal eye movements

An individual with cerebellar atrophy sometimes cannot even sit on the edge of a bed without falling because of an uncontrollable bobbing motion of the trunk or head. An affected person might not be able to achieve an intended position of their hand, arm, leg or eye.

Cerebellar atrophy can affect the person’s ability to perform everyday tasks like preparing food or getting dressed that need fine motor coordination. Speech and swallowing may also be impaired. The cerebellum plays a role in certain types of thinking, and cerebellar atrophy can cause cognitive and mood problems. Patients can have problems with “executive functions” like making plans. Some Dilantin users have reported irritability, anxiety, or depression.

There is no specific treatment for cerebellar toxicity or the resulting ataxia (movement problems). Treating the underlying cause can sometimes resolve the ataxia. When ataxia is caused by a viral infection, it often clears up on its own over time. But when ataxia arises from cerebellar atrophy as a Dilantin side effect, stopping the medication may alleviate some of the symptoms but may not eliminate them entirely.

Other Dilantin Side Effects

Dilantin is one of many drugs associated with the serious allergic skin reactions conditions Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Stevens-Johnson syndrome begins with flu-like symptoms, followed by a painful red or purplish rash that spreads and blisters. When the affected skin sheds, it exposes underlying tissues to potential infection and further compounds the condition. Stevens-Johnson is estimated to be fatal 30 percent of the time.

The Mayo Clinic says Dilantin has been linked with the serious and life-threatening condition called Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). Dilantin can cause liver damage, and can lower the number of white blood cells in your blood, increasing the chance of infection. In addition, the drug can lower the number of platelets, which are necessary for proper blood clotting.

Research on Effects of Dilantin on the Brain

The study of Dilantin’s effect on the brain is complicated by the fact that seizures themselves can cause brain atrophy. A 1994 research study took this into account when comparing the cerebral cortex of patients who took Dilantin with those who did not take the drug. The researchers found that the cerebella of those taking Dilantin were much smaller than the cerebella of patients not taking the drug. They concluded that the incidence and severity of cerebellar atrophy were linked to the dose of Dilantin.

Cerebellar atrophy is more likely to occur after long-term use of Dilantin and the drug reaches levels higher than the therapeutic range. But incidents of cerebellar atrophy have been seen even when the drug is within a normal range. Elderly patients are at greater risk of Dilantin toxicity, which puts them at greater risk for brain side effects. Taking medications for abnormal heart rhythms, alcoholism, ulcers and tuberculosis can also increase the chances of developing Dilantin toxicity.

Legal Help for Dilantin Side Effects

If you have taken Dilantin and have developed brain atrophy or other side effects, the attorneys at Parker Waichman LLP can help you evaluate your case. For a free, no obligation evaluation, fill out the contact form or call 1-800-YOURLAWYER (1-800-968-7529).


This entry was posted in Dilantin, Health Concerns, Pharmaceuticals. Bookmark the permalink.

© 2005-2020 Parker Waichman LLP ®. All Rights Reserved.