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brivaracetam vs phenytoin

Side-by-side comparison of brivaracetam and phenytoin Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

minor Known Drug Interaction

(7.2) Phenytoin: Because phenytoin concentrations can increase, phenytoin levels should be monitored in patients on concomitant brivaracetam. 7.3 Phenytoin Because brivaracetam can increase plasma concentrations of phenytoin, phenytoin levels should be monitored in patients when concomitant brivaracetam is added to or discontinued from ongoing phenytoin therapy [see Clinical Pharmacology (12.3)] .

Recommendation: Your doctor should check your phenytoin blood levels regularly if you start or stop taking brivaracetam.

Drug Class
brivaracetam Anticonvulsant (SV2A Ligand)
phenytoin Anticonvulsant (Hydantoin)
Type
brivaracetam Prescription
phenytoin Prescription
Summary
brivaracetam

Brivaracetam is a medicine used to treat partial-onset seizures. It helps to reduce the number of seizures you have.

phenytoin

Phenytoin injection is used to treat certain types of seizures. It can also prevent seizures during or after neurosurgery.

What It Treats
brivaracetam

Brivaracetam is used to treat partial-onset seizures. These seizures start in one part of the brain. It can be used alone or with other seizure medicines for people 1 month and older.

phenytoin

This medicine treats generalized tonic-clonic status epilepticus, a type of prolonged seizure. It also helps prevent and treat seizures that may happen during or after brain surgery. Sometimes, it can be used for a short time instead of the oral form of phenytoin when you cannot take the medicine by mouth.

How It Works
brivaracetam

Brivaracetam binds to a protein in the brain called SV2A. This helps to reduce the electrical activity in the brain that causes seizures. It helps to stabilize nerve cells.

phenytoin

Phenytoin works by slowing down the signals in the brain that cause seizures. It stabilizes nerve cell membranes, reducing excessive electrical activity. This helps to prevent seizures from starting or spreading.

Common Side Effects
brivaracetam
  • Feeling sleepy or tired
  • Dizziness
  • Fatigue
  • Nausea or vomiting
phenytoin

No common side effects listed.

FAERS Reports
brivaracetam
  • Seizure 2,902
  • Using the medicine for a condition it's not approved for 1,036
  • The medicine is not working 896
  • Tiredness 518
  • Sleepiness 442
phenytoin
  • The medicine is not working 2,670
  • The medicine is reacting with another medicine 1,547
  • Seizure 1,382
  • Poisoning from different substances 1,353
  • Convulsion 1,260
Serious Warnings
brivaracetam

Brivaracetam can cause suicidal thoughts or actions. Watch for new or worsening depression, suicidal thoughts or behavior, or unusual changes in mood. Tell your doctor right away if you have any of these symptoms. Do not stop taking brivaracetam suddenly, as this may increase your risk of seizures.

phenytoin

This medicine can cause serious heart problems if given too quickly. The injection rate should not be faster than 50 mg per minute for adults, and 1 to 3 mg/kg/min (or 50 mg per minute, whichever is slower) for children. Your heart will be monitored closely during and after the injection.

Pregnancy
brivaracetam

Tell your doctor if you are pregnant or plan to become pregnant. There is a pregnancy registry for women who take brivaracetam during pregnancy. Contact the North American Antiepileptic Drug (NAAED) Pregnancy Registry at 1-888-233-2334.

phenytoin

Taking phenytoin during pregnancy may increase the risk of birth defects. If you are pregnant or plan to become pregnant, talk to your doctor about the risks and benefits of this medicine.

How to Read This brivaracetam vs phenytoin Comparison

brivaracetam is classified in the Anticonvulsant (SV2A Ligand) drug class, while phenytoin sits within the Anticonvulsant (Hydantoin) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, brivaracetam has 5,794 submissions while phenytoin has 8,212. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to brivaracetam can cause the levels of phenytoin in your blood to rise. this happens because brivaracetam interferes with how your body processes and removes phenytoin.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between brivaracetam and phenytoin — always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.