Dilantin

Seizure Control

Dilantin is primarily prescribed to control certain types of seizures in people with epilepsy. These include:

• Generalized tonic-clonic seizures: Also known as grand mal seizures, these involve a loss of consciousness and violent muscle contractions.
• Complex partial seizures: These seizures start in one area of the brain and can affect awareness or cause repetitive movements.

Neurosurgery Support

This medication is also used by healthcare providers to prevent or treat seizures that may occur during or following surgery on the brain or nervous system.

Limitations of Use

Dilantin is not effective for all types of seizure disorders. For example, it is generally not used to treat absence seizures, which involve brief lapses in consciousness.

Mechanism of Action

Dilantin belongs to a class of drugs known as anticonvulsants or anti-epileptics. It works by slowing down the electrical impulses in the brain that cause seizures.

The medication helps manage seizure activity through the following processes:

• Stabilizing nerve cells: It targets the motor cortex of the brain, where it helps stabilize the threshold against hyperexcitability. This prevents nerve cells from firing too quickly or repeatedly.
• Regulating sodium channels: Dilantin works by blocking certain sodium channels in the brain. By limiting the movement of sodium ions across cell membranes, it prevents the excessive electrical discharge that leads to a seizure.
• Preventing seizure spread: By calming overactive neurons, the medication helps stop abnormal electrical activity from spreading to other parts of the brain.

Common Side Effects

Many people using Dilantin experience mild side effects as their body adjusts to the medication. Common issues include:

• Drowsiness, dizziness, or confusion
• Slurred speech or loss of coordination
• Nausea, vomiting, or constipation
• Headache
• Overgrowth of the gums (gingival hyperplasia)
• Increased hair growth on the face or body
• Coarsening of facial features

Serious Side Effects

While less common, some side effects require immediate medical attention. Contact a healthcare provider right away if you experience:

• Severe skin reactions: Fever, sore throat, burning eyes, or a red or purple skin rash that spreads and causes blistering and peeling.
• Mood or behavior changes: New or worsening depression, anxiety, or thoughts about self-harm.
• Liver problems: Yellowing of the skin or eyes (jaundice), dark urine, or pain in the upper right side of the stomach.
• Swollen glands: Swelling in the neck, armpits, or groin, often accompanied by fever or joint pain.
• Blood disorders: Unusual bruising, pale skin, or frequent infections.
• High blood sugar: Increased thirst, frequent urination, or fruity breath odor.
• Bone health: Long-term use may lead to weakening of the bones.

Serious Skin Reactions

Dilantin can cause rare but life-threatening skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis. These reactions are more common in people of Asian descent who carry a specific genetic marker known as HLA-B*1502. Testing for this marker is often recommended before starting treatment.

Suicidal Thoughts and Behavior

Anti-seizure medications, including Dilantin, may increase the risk of suicidal thoughts or actions in a small number of people. These changes in mood or behavior can occur as early as one week after starting the medication.

Abrupt Discontinuation

Stopping Dilantin suddenly can cause a rapid increase in seizure frequency or lead to status epilepticus, a condition where seizures do not stop. If the medication must be stopped, it is generally done through a gradual reduction in dose.

Organ and Systemic Risks

• Liver Injury: Severe and sometimes fatal liver damage can occur. Monitoring for symptoms like yellowing of the skin or eyes is common practice.
• Blood Disorders: Dilantin may affect blood cell production, leading to low levels of red blood cells, white blood cells, or platelets.
• Hypersensitivity: A condition called Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) can affect multiple organs and requires immediate medical attention.

Pregnancy and Development

Taking Dilantin during pregnancy may increase the risk of birth defects and can cause life-threatening bleeding problems in the newborn. It may also interfere with the effectiveness of hormonal birth control.

Bone Health

Long-term use of Dilantin can interfere with vitamin D metabolism, potentially leading to softened bones (osteomalacia), decreased bone density, and an increased risk of fractures.

Pregnancy

Taking Dilantin during pregnancy may increase the risk of birth defects or other health problems for the baby. However, having a seizure during pregnancy can also be dangerous for both the parent and the baby. It is important to talk with a healthcare provider about the risks and benefits of continuing this medication while pregnant.

Dilantin can cause a bleeding disorder in newborns. To help prevent this, healthcare providers may recommend taking Vitamin K during the final weeks of pregnancy and giving Vitamin K to the baby immediately after birth.

Do not start or stop taking seizure medication during pregnancy without medical advice. Stopping the medication suddenly can cause severe, long-lasting seizures that could harm the pregnancy.

Breastfeeding

Dilantin passes into breast milk. Because of the potential for side effects in the nursing infant, breastfeeding while taking this medication is generally not recommended. Individuals should discuss their options with a healthcare provider to determine the safest approach for their situation.

Oral Dosage Forms

Dilantin is provided in the following oral formulations:

• Extended-release capsules: These are phenytoin sodium capsules designed to release the medication slowly into the body.
• Chewable tablets: These are phenytoin tablets that can be chewed or swallowed whole.
• Oral suspension: This is a liquid form of phenytoin that must be shaken thoroughly before each dose is measured.

Injectable Form

Dilantin is also available as an injectable solution (phenytoin sodium). This form is typically administered by a healthcare professional in a hospital or clinical setting, often for the treatment of severe or continuous seizures, or when oral administration is not possible.

FDA Approval and Indications

Dilantin is approved by the U.S. Food and Drug Administration (FDA) to treat generalized tonic-clonic (grand mal) seizures and complex partial seizures. It is also indicated for the prevention and treatment of seizures that may occur during or after neurosurgery.

Boxed Warning

The FDA requires a boxed warning for phenytoin injection due to the risk of severe cardiovascular events. If the medication is administered too rapidly via an intravenous (IV) line, it can lead to dangerously low blood pressure and life-threatening heart rhythm changes. Because of these risks, the rate of infusion must be strictly limited, and patients require continuous cardiac monitoring during administration.

Prescription Status

Dilantin is a prescription-only medication. It is available in various formulations, including extended-release capsules, oral suspensions, and injectable solutions, to meet different clinical needs.

Risks of Abrupt Discontinuation

It is critical not to stop taking Dilantin without first consulting a healthcare professional. Suddenly discontinuing this medication can cause seizures to return or happen more frequently. In some cases, stopping the drug abruptly can trigger status epilepticus, a medical emergency where seizures follow one another without a recovery period or last for a long duration.

Safe Withdrawal Process

If Dilantin needs to be discontinued, healthcare providers typically recommend a gradual reduction in dosage rather than stopping all at once. This tapering process helps the body adjust and reduces the risk of withdrawal-related seizures.

• Medical Supervision: Always follow a doctor's specific instructions for lowering the dose.
• Side Effects: Even if you experience side effects or mood changes, do not stop the medication until you have spoken with a healthcare provider.
• Consistency: Maintain your regular dosing schedule until your doctor advises otherwise to ensure seizure control remains stable.