WARNING

Cerebyx, or fosphenytoin, is a medication primarily used to prevent and control seizures. Like any medication, it carries certain risks and potential side effects that should be considered:

• Allergic reactions: Some people may experience allergic reactions to Cerebyx, which can range from mild rashes to severe reactions such as anaphylaxis.
• Liver problems: Cerebyx can affect liver function, potentially leading to liver damage or abnormal liver tests. Monitoring liver function is important during treatment.
• Cardiovascular effects: It may cause changes in heart rate or blood pressure, which can be problematic for individuals with pre-existing heart conditions.
• Central nervous system effects: Common side effects include dizziness, drowsiness, and confusion. In some cases, it can cause more serious neurological effects such as ataxia (loss of coordination) or slurred speech.
• Skin reactions: Serious skin reactions like Stevens-Johnson syndrome or toxic epidermal necrolysis are rare but possible with Cerebyx use.
• Bone health: Long-term use of Cerebyx may lead to weakening of bones (osteoporosis), especially in elderly patients or those with other risk factors.
• Drug interactions: Cerebyx can interact with other medications, potentially altering their effects or causing adverse reactions. It’s crucial to inform healthcare providers about all medications being taken.
• Pregnancy and breastfeeding: It may not be safe during pregnancy or breastfeeding, as it can pass into breast milk and affect the fetus or nursing infant.
• Overdose: Taking too much Cerebyx can lead to symptoms such as nausea, vomiting, seizures, and cardiac arrhythmias, which require immediate medical attention.

Patients prescribed Cerebyx should be monitored closely by healthcare providers to manage these risks and ensure the medication’s effectiveness in controlling seizures outweighs potential adverse effects.

Why is this medication prescribed?

Cerebyx (fosphenytoin) is prescribed primarily for the prevention and control of seizures in individuals who have certain types of epilepsy or who are at risk of seizures during neurosurgery. It is a prodrug of phenytoin, meaning it is converted into phenytoin in the body, and it works by stabilizing electrical activity in the brain.

How should this medicine be used?

Here’s how Cerebyx should typically be used:

• Dosage: The dosage of Cerebyx is individualized based on factors such as the patient’s age, weight, medical condition, and response to treatment. It is usually administered intravenously (IV) in hospital settings for acute seizure control or during neurosurgical procedures.
• Administration: Healthcare providers administer Cerebyx as an IV infusion over several minutes to hours, depending on the dose and patient’s condition. It should not be given as a rapid injection due to the risk of adverse effects on blood vessels and heart rhythm.
• Monitoring: During treatment with Cerebyx, patients are closely monitored for signs of therapeutic effectiveness and potential side effects. This includes monitoring of blood levels of the active metabolite (phenytoin) to ensure it stays within the therapeutic range.
• Switching to oral medication: If a patient’s condition stabilizes, they may be switched from Cerebyx IV to oral phenytoin or another oral antiepileptic medication to maintain seizure control.
• Duration of treatment: Treatment duration with Cerebyx varies depending on the individual’s medical condition and response to the medication. It is typically used for short-term seizure control during acute episodes or surgeries.

It’s important for patients and caregivers to follow healthcare providers’ instructions closely regarding the use of Cerebyx to maximize effectiveness and minimize potential risks associated with the medication.

Other uses for this medicine

While Cerebyx is primarily used for seizures, it has also been investigated or used off-label for other conditions such as:

• Status Epilepticus: It is sometimes used as a first-line treatment for status epilepticus, a medical emergency characterized by prolonged seizures.
• Prophylaxis: It may be used to prevent seizures in certain high-risk patients, such as those undergoing neurosurgery.

What special precautions should I follow?

Special precautions to follow when using Cerebyx:

• Monitoring: Regular monitoring of blood levels of the active metabolite phenytoin is necessary to ensure therapeutic levels are maintained. This helps in optimizing seizure control and minimizing the risk of toxicity.
• Kidney and liver function: Cerebyx can affect kidney and liver function. Patients with impaired kidney or liver function may require adjustments in dosage or closer monitoring to prevent potential complications.
• Cardiovascular effects: Due to its potential to cause changes in heart rate and blood pressure, patients with pre-existing heart conditions or hypertension should be closely monitored while on Cerebyx.
• Allergic reactions: Individuals with a history of hypersensitivity reactions to Cerebyx or phenytoin should avoid its use. Allergic reactions can range from mild rash to severe anaphylaxis.
• Pregnancy and breastfeeding: Cerebyx should be used with caution during pregnancy only if the potential benefits outweigh the risks. It can pass into breast milk, so breastfeeding mothers should discuss the risks and benefits with their healthcare provider.
• Drug interactions: Cerebyx can interact with many other medications, including oral contraceptives, anticoagulants, and other antiepileptic drugs. Healthcare providers should be informed about all medications being taken to avoid potential interactions.
• Bone health: Long-term use of Cerebyx may lead to decreased bone density (osteopenia or osteoporosis), particularly in older adults or those with other risk factors. Adequate calcium and vitamin D intake and regular bone density monitoring may be recommended.

Patients should always follow their healthcare provider’s instructions closely regarding the use of Cerebyx, including dosage, monitoring, and any necessary precautions, to ensure safe and effective treatment.

What special dietary instructions should I follow?

• Consistent diet: It’s generally recommended to maintain a consistent diet while taking Cerebyx, as sudden changes in diet can affect the absorption and metabolism of the medication.
• Vitamin supplementation: Some individuals on long-term Cerebyx therapy may benefit from calcium and vitamin D supplementation to support bone health.
• Avoid alcohol: Alcohol can interact with Cerebyx, potentially increasing the risk of side effects such as dizziness and drowsiness. It’s advisable to limit or avoid alcohol consumption.

What should I do if I forget a dose?

• Take it as soon as you remember: If you miss a dose, take it as soon as you remember. However, if it’s almost time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule.
• Do not double up: Do not take a double dose to make up for a missed one. Taking too much Cerebyx at once can increase the risk of side effects and toxicity.
• Consult your healthcare provider: If you’re unsure about what to do when you miss a dose, or if you have missed multiple doses, contact your healthcare provider or pharmacist for guidance.

What side effects can this medication cause?

Cerebyx (fosphenytoin) can cause various side effects, ranging from mild to severe. Not everyone experiences these side effects, and their severity can vary depending on individual factors. Common side effects of Cerebyx include:

• Dizziness: Feeling lightheaded or unsteady.
• Drowsiness: Feeling unusually sleepy or fatigued.
• Nausea and vomiting: Upset stomach with or without vomiting.
• Injection site reactions: Pain, redness, or swelling at the site where the medication is injected.
• Headache: Mild to moderate headaches.
• Blurred vision: Temporary blurring or difficulty focusing vision.
• Low blood pressure: Especially during rapid administration.
• Arrhythmias: Abnormal heart rhythms in some cases.
• Skin rash: Mild rashes to more severe reactions like Stevens-Johnson syndrome (rare but serious).

Less common but more serious side effects may include:

• Allergic reactions: Such as itching, swelling, severe dizziness, or trouble breathing.
• Liver problems: Abnormal liver function tests or, rarely, liver damage.
• Bone problems: Long-term use may lead to weakening of bones (osteopenia or osteoporosis).
• Blood disorders: Such as decreased platelets or white blood cells.

It’s essential to report any unusual or severe side effects to your healthcare provider promptly. Some side effects, like dizziness or drowsiness, may improve as your body adjusts to the medication. However, serious side effects require immediate medical attention.

Patients taking Cerebyx should be monitored regularly by their healthcare providers to manage and minimize these potential side effects while ensuring the medication’s effectiveness in controlling seizures or other conditions for which it is prescribed.

What should I know about storage and disposal of this medication?

Storage of Cerebyx:

• Temperature: Cerebyx should be stored at room temperature, ideally between 20°C to 25°C (68°F to 77°F).
• Protect from light: Keep Cerebyx vials or containers away from direct light.
• Do not freeze: Ensure that Cerebyx is not frozen. Freezing can affect its stability and effectiveness.
• Proper packaging: Keep Cerebyx in its original packaging until ready to use to protect it from moisture and other environmental factors.
• Secure storage: Store Cerebyx out of reach of children and pets, in a secure place where it cannot be accidentally ingested.

Disposal of Cerebyx:

• Unused medication: If there is any leftover Cerebyx that is no longer needed, it should be disposed of properly.
• Local guidelines: Follow local guidelines or consult with your pharmacist on how to dispose of unused medications. Some areas provide drug take-back programs or specific instructions for safe disposal.
• Do not flush: Do not flush Cerebyx down the toilet unless instructed to do so. This is generally not recommended due to potential environmental concerns.

In case of emergency/overdose

• Symptoms: Symptoms of Cerebyx overdose may include severe dizziness, confusion, slurred speech, uncontrollable eye movements, loss of consciousness, and seizures.
• Seek medical help: In case of overdose or if someone has ingested Cerebyx accidentally, seek immediate medical attention or call your local emergency services (such as 911).
• Poison control: You can also contact the Poison Control Center at 1-800-222-1222 for guidance on what to do in case of overdose.

What other information should I know?

• Regular monitoring: Regularly monitor blood levels of phenytoin (the active metabolite of Cerebyx) as recommended by your healthcare provider. This helps ensure that the medication remains within the therapeutic range.
• Follow-up appointments: Attend follow-up appointments with your healthcare provider to assess the effectiveness of Cerebyx and monitor for any potential side effects or complications.
• Medication interactions: Inform your healthcare provider about all medications you are taking, including over-the-counter drugs, vitamins, and supplements. Cerebyx can interact with other medications, potentially affecting their effectiveness or increasing the risk of side effects.
• Patient education: Understand the importance of taking Cerebyx as prescribed and follow your healthcare provider’s instructions carefully. Do not change the dosage or stop taking the medication without consulting your doctor.
• Medical alert bracelet: Consider wearing a medical alert bracelet or carrying a card that identifies you as taking Cerebyx in case of emergencies.

By understanding these guidelines for storage, disposal, emergency procedures, and additional information, you can safely manage your use of Cerebyx and optimize its effectiveness in treating seizures or other conditions for which it is prescribed.