The side effects of Dilantin toxicity may include the shrinking of overall mass in an area of the brain known as the cerebellum.

Dilantin, also known generically as phenytoin, is an anticonvulsant drug generally used to treat various forms of epilepsy or seizure disorder. Tonic-clonic and partial seizures are two of the types of seizures treated with this medication.  Dilantin is not an effective preventative treatment for absence seizures. In its intravenous form, it is used to stop a very serious, life-threatening condition called status epilepticus.

Although discovered in 1908 by a German chemist, its use for the prevention of seizures was not realized until 1936. While the side effects of Dilantin toxicity appear to include shrinkage in a lobe found at the base of the main brain and forward of the brain stem, the medication is still listed on the World Health Organization’s List of Essential Medicines.  This list is supposedly includes some of the safest and most effective medications known and needed in public health systems. Some of the reasons Dilantin may be on the list include that it is an effective treatment for seizures, has a long successful history, and is inexpensive, with a domestic cost of about $30 a month.

According to epilepsy.com, side effects while initialing taking Dilantin may include:

• Rapid side-to-side movement of the eyes, also known as nystagmus
• Poor ability to concentrate, attention span, memory issues
• Slurred speech
• Uncoordinated body movements
• Shakiness in the hands or feet

Typically, these experiences go away after being on the drug for a while. If side effects continue for any length of time, they can be considered the side effects of Dilantin toxicity and a revision of dose should be evaluated. The blood level of the medication may be too high.

The side effects of Dilantin toxicity are also seen when a person is on this drug for too long a period of time, regardless of whether the medication is at a normal therapeutic level. This is when shrinkage of the cerebellum has been noted.

What Does the Cerebellum Do?

The cerebellum controls the finer execution of the voluntary muscle movements of the body. If a person is suffering from cerebellar atrophy, they will likely demonstrate ataxia, a lack of coordination over major muscle movements. Ataxia often presents itself in persons experiencing long-term use side effects of Dilantin toxicity as a gait abnormality, such as lurching, or walking with a slow unsteady pace.

The sufferer will likely experience dizziness and a sense of imbalance may predominate the person’s overall movement. The person may have difficulty negotiating finer tongue movements involved in correct, easily understood speech. Sufferers may also have trouble with muscle control needed for using writing instruments, such as a pen or pencil.

For sufferers of cerebellar atrophy, stopping Dilantin is sometimes all that is needed to end the side effects, but this must be done under the care of a specialist in order to avoid putting the patient into a perpetual state of seizure activity. An alternative treatment for the seizure disorder should be introduced gradually as the phenytoin is removed.

Sometimes, it is found that the long-term side effects of Dilantin toxicity do not go away with removal of the medication from the treatment regimen. This represents a significant loss of brain cells, also known as neurons, and the connections between them.