Dilantin (phenytoin) was one of the first available anticonvulsant medications.
It is primarily used for the prevention of seizures. It is best used to control seizures that affect the entire brain (tonic-clonic seizures) or those that affect half of the brain or one specific brain area (partial seizures).
It is not a significant drug of abuse. Dilantin is not listed by the U.S. Drug Enforcement Administration (DEA) as a controlled substance, but it does require a prescription from a physician.
The drug can be administered in pill form orally or used as a liquid intravenously. Intravenous use of Dilantin is most often designed to address seizures that have a duration of greater than five minutes, and it can be used to treat people who have status epilepticus (multiple seizures in a very short timeframe).
Off-Label Uses
Phenytoin may also be used for the treatment of irregular heartbeat (arrhythmias) and certain types of pain (usually neuropathic pain).
Anticonvulsant medications, including Dilantin, have been used to treat issues associated with bipolar disorder, although this is not a first-line approach to addressing bipolar disorder symptoms.
Dilantin remains one of the most prescribed drugs worldwide, but it is no longer considered to be the first-line treatment for seizure disorders. It is often used in conjunction with other medications or as an adjunctive approach to treatment for seizure disorders.
It remains important in the treatment of status epilepticus, seizures that occur in individuals after having surgery, and seizures that occur for other reasons in individuals who are hospitalized.
How Does Dilantin Work?
Dilantin reduces the activity of the neurons in the brain, which results in its ability to control seizures. It is believed to affect the sodium channels in the neurons, and this reduces unrestrained neuronal firing, which is associated with seizure activity.
Because of this mechanism of action, its use can also produce several potential side effects.
Side Effects
Dilantin is a powerful medication that produces significant alterations in the functioning of the neurons in the brain and spinal cord. Medications that alter the functioning of the brain in anyone, even if this functioning is considered to be abnormal, can change the structure of the neurons and neuropathways. This can lead to other changes in the body.
As a result, there can be numerous side effects associated with Dilantin use. Some of the short-term and long-term side effects include:
- Overgrown gums
- Nausea, vomiting, and stomach cramps
- Loss of appetite
- Problems with movement, coordination, dizziness, and headache.
- Hypotension (low blood pressure)
- Insomnia and other sleep issues
- Deterioration of the bones, osteoporosis, or problems with bone marrow
- Mild tremors
- Liver damage
- Tingling, numbness, or pain in the hands, feet, or legs (neuropathy)
- Cerebellar atrophy or even atrophy of other areas of the brain
- Suicidal thoughts
Toxicity & Overdose
Long-term use of Dilantin may increase the potential for toxic effects and overdose. Individuals who overdose on Dilantin may do so accidentally or as an attempt to harm themselves. Combining Dilantin with drugs of abuse can increase the risk of toxic effects or overdose.
Symptoms of an overdose on Dilantin may include:
- Lethargy, confusion, or unconsciousness
- Nystagmus (uncontrollable side-to-side movement of the eyes), staggering gait, or tremors
- Nausea and/or vomiting
- Low blood pressure
- Slurred speech
- A significantly reduced breathing rate (respiratory suppression)
- Coma
An overdose of Dilantin is rarely fatal, but fatalities can occur.
Treatment will vary depending on the severity of the overdose. They may consist of IV fluids, medications to address specific symptoms, activated charcoal if the overdose was taken orally, and intubation to assist with breathing.
Is Dilantin a Potential Drug of Abuse?
There are some scattered research reports and anecdotal reports of abuse of anticonvulsant medications, including some reports of Dilantin abuse; however, the majority of these cases occur in the context of someone abusing multiple drugs.
Individuals who abuse anticonvulsant medications often also have a psychiatric disorder or some significant cognitive issue. Those who abuse anticonvulsant medications in conjunction with other drugs of abuse are usually seeking some type of unique psychoactive effects. They may believe that adding Dilantin to the mix will increase the euphoria associated with other drugs.
Alcohol is one of the most common substances used by polydrug abusers. Drinking alcohol, in conjunction with Dilantin, may reduce the antiseizure effects of the drug and increase the side effect profile, but it will not likely result in any unique psychoactive effects other than those produced by alcohol.
Even though Dilantin can be used to address certain types of pain in some cases, it does not produce significant euphoria as prescription opioids do.
Treatment For Dilantin Abuse
There is no specific protocol to address abuse of Dilantin.
People who abuse Dilantin with other drugs would most likely be treated for polysubstance abuse issues. Individuals with co-occurring mental health disorders or cognitive problems would be treated accordingly for these issues.
Even though serious physical dependence on Dilantin is not a concern, people who have been using Dilantin regularly for seizure control and suddenly discontinue the use of the medication are likely to experience an exacerbation of their seizures, which can be potentially dangerous and even fatal.
Individuals should only take Dilantin while under the care of a physician and according to the instructions provided by the physician. Dilantin should only be discontinued under the supervision of a doctor.
