Dilantin (phenytoin, or PHT), an anti-seizure drug, has proven useful for preventing seizures in epileptic patients, head injury victims and those suffering from brain tumors. However, there are a number of risk factors involved in taking this medication.

Among the more serious side effects is Dilantin cerebellar atrophy, a type of brain degeneration. Other Dilantin side effects range from minor to life-threatening.

Anyone who has been prescribed Dilantin or is considering undergoing treatment with this medication should be aware of the risks and be prepared to discuss any concerns with a qualified medical professional.

Dilantin History

Phenytoin was originally developed in 1908 by a German chemist named Heinrich Biltz. He sold the patent to U.S. pharmaceutical company Parke-Davis (now a subsidiary of Pfizer), but its usefulness was not realized until the late 1930s, when its anti-seizure properties were discovered.

Prior to that time, the standard treatment for epilepsy was phenobarbital, which is still used for controlling seizures in young children. However, unlike phenobarbital, phenytoin did not cause sleepiness.

The U.S. Food and Drug Administration approved phenytoin for the control of epileptic seizures in 1953. In addition to seizures, indications for Dilantin include arrhythmia and tachycardia (irregular or rapid heartbeat, trigeminal neuralgia (a chronic facial pain), and digoxin poisoning (caused by an overdose of a medication used to treat heart conditions or ingesting foxglove).

Dilantin and Cerebellar Atrophy

Researchers believe cerebellar atrophy is the result of an accumulation of Dilantin in the cerebral cortex. This is the thin layer covering the cerebrum, the largest part of the human brain. The cerebrum controls voluntary muscle movement, speech and memory, as well as sensory processing.

Cerebellar atrophy results in the loss of neurons and their connections, or synapses. It is similar to pulling the wires out of a piece of electronic equipment.

Because of this, cerebellar atrophy can result in loss of motor control (ataxia), dementia symptoms and speech difficulties. This side effect appears to be less dependent on the amount of Dilantin taken and more on the length of time the drug has been taken. In some cases, patients have recovered after being taken off of the drug if the damage is not too extensive. For others however, the damage is permanent.

Other Dilantin Side Effects

Another potentially serious side effect of Dilantin is peripheral neuropathy, or nerve damage of the extremities. Peripheral neuropathy has also been tied to Levaquin antibiotic use.

Patients treated with Dilantin may also experience hypotension (dangerously low blood pressure), skin rashes and blisters, narcolepsy and impaired liver function.

More common and less serious Dilantin side effects include nausea and loss of appetite, insomnia, brain fog, headaches, uncontrollable rapid eye movement (nystagmus) and poor coordination.

If you have concerns about Dilantin side effects, there may be alternatives that can treat your condition. It is unwise to discontinue any medication you have been prescribed until you have discussed it with your physician.  Your doctor can advise you about withdrawing from Dilantin and starting a different medication.