Sabril

Approved Uses

Sabril is primarily used for two specific conditions:

• Infantile Spasms: It is used as a single medication (monotherapy) to treat infants between 1 month and 2 years of age who have infantile spasms.
• Complex Partial Seizures: It is used alongside other medications to treat refractory complex partial seizures in adults and children 2 years of age and older.

Usage Considerations

This medication is typically prescribed only when a patient has not responded well to several other seizure treatments. Because of the potential for serious side effects, healthcare providers must determine that the benefits of seizure control outweigh the risks for the individual patient.

Mechanism of Action

Sabril belongs to a class of medications known as anticonvulsants or antiepileptics. It works by targeting a specific chemical in the brain called gamma-aminobutyric acid (GABA). GABA is a neurotransmitter that helps regulate nerve activity by sending calming signals throughout the central nervous system.

In a typical brain, an enzyme called GABA transaminase breaks down GABA once it has finished its job. Sabril works by permanently blocking this enzyme from functioning. Because the enzyme can no longer break down GABA, the levels of this calming chemical increase in the brain.

By maintaining higher levels of GABA, Sabril helps to:

• Reduce the excessive electrical activity in the brain that causes seizures.
• Stabilize nerve cell activity.
• Prevent the spread of seizure signals to other parts of the brain.

Common Side Effects

Common side effects of Sabril may include:

• Dizziness and drowsiness
• Fatigue or feeling tired
• Headache
• Weight gain
• Joint or muscle pain
• Memory problems or confusion
• Tremors or shaking
• Blurred vision
• Nausea, vomiting, diarrhea, or constipation
• Irritability

In infants and children, common side effects may also include ear infections, cough, and increased sleepiness.

Serious Side Effects

Sabril can cause serious side effects that require immediate medical attention. These include:

• Permanent Vision Loss: Sabril can cause permanent damage to the peripheral vision (side vision). This risk increases with higher doses and longer use, but can occur at any time during treatment.
• Changes in Mood or Behavior: New or worsening depression, anxiety, panic attacks, or thoughts of self-harm.
• Neurological Issues: Difficulty walking, loss of balance, or unusual eye movements.
• Severe Allergic Reactions: Swelling of the face, lips, or tongue, or difficulty breathing.
• Worsening Seizures: An increase in the frequency or severity of seizures.
• Edema: Significant swelling in the arms, hands, legs, or feet.

Permanent Vision Loss

Sabril can cause permanent loss of peripheral vision (side vision). This risk applies to everyone taking the medication, including infants and children. The risk of vision loss increases with higher doses and longer duration of use, but it can occur at any time, even shortly after starting treatment. Because this vision loss is permanent and may not be noticed until it is severe, regular vision testing is required before starting the medication, every three months during treatment, and for six months after stopping.

REMS Program

Due to the risk of vision loss, Sabril is only available through a restricted distribution program called the Vigabatrin REMS Program. Healthcare providers and pharmacies must be certified in this program to prescribe or dispense the medication.

Suicidal Thoughts and Behavior

Anti-seizure medications, including Sabril, may increase the risk of suicidal thoughts or actions in a small number of people. It is important to monitor for changes in mood, behavior, or worsening depression.

Withdrawal and Seizure Risk

Stopping Sabril suddenly can cause serious problems, including seizures that do not stop. If the medication is discontinued, it is typically done gradually under medical supervision.

Other Serious Precautions

• Brain abnormalities: Changes in brain scans (MRI) have been observed in some infants treated for infantile spasms.
• Sleepiness and fatigue: The medication can cause significant drowsiness, which may impair the ability to perform tasks requiring alertness.
• Weight gain and swelling: Some people experience significant weight gain or swelling in the hands, legs, or feet (edema).
• Anemia: Sabril may cause a decrease in red blood cell counts.

Pregnancy

The effects of Sabril on human pregnancy are not fully known, but animal studies suggest that the medication may cause birth defects. It should be used during pregnancy only if the potential benefit to the mother outweighs the potential risk to the fetus.

Women who become pregnant while taking Sabril are often encouraged to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry. This registry monitors the health of babies born to women who take seizure medications during pregnancy.

Breastfeeding

Sabril is known to pass into breast milk. Because the potential for serious side effects in a nursing infant is unknown, a decision should be made whether to discontinue breastfeeding or discontinue the drug, taking into account the importance of the medication to the mother's health.

Available Forms

Sabril is provided in the following oral formulations:

• Oral Tablets: These are film-coated tablets intended to be swallowed.
• Powder for Oral Solution: This form is provided in packets. The powder must be dissolved in water before administration.

FDA Approval and Indications

The U.S. Food and Drug Administration (FDA) first approved Sabril in 2009. It is indicated for two specific uses:

• Treatment of infantile spasms in infants 1 month to 2 years of age, when the potential benefits outweigh the risk of vision loss.
• Add-on treatment for adults and pediatric patients 2 years of age and older with refractory complex partial seizures who have not responded adequately to several alternative treatments.

Boxed Warning and REMS Program

Sabril carries a boxed warning regarding the risk of permanent vision loss. Because of this risk, the drug is only available through a restricted distribution program called the Vigabatrin REMS Program. Both healthcare providers and patients must be enrolled in the program to prescribe or receive the medication.

The REMS program requires regular vision testing before starting treatment, during treatment, and after treatment has ended. However, vision testing may not prevent vision damage, and the loss of vision can be permanent even after the drug is stopped.

Generic Availability

Generic versions of vigabatrin tablets and powder for oral solution have been approved by the FDA and are available on the market.

Risks of Sudden Discontinuation

It is important not to stop taking Sabril abruptly. Doing so can cause withdrawal seizures, which may be more frequent or last longer than the seizures experienced before starting the medication. Even if you notice changes in your vision or other side effects, you should consult your doctor before making any changes to your dosage.

Gradual Dose Reduction

To safely stop taking Sabril, healthcare providers typically recommend a gradual reduction in dosage. This tapering process allows the body to adjust and helps prevent the return or worsening of seizures. Your doctor will determine the appropriate schedule for decreasing the dose based on your specific medical needs.

Medical Guidance

Always follow the specific instructions provided by your healthcare team regarding the discontinuation of this medicine. Do not skip doses or stop the medication entirely without medical supervision, as this increases the risk of serious complications.