brivaracetam vs phenytoin
PlainMeds reviewed this comparison against our methodology in August 2026. It places FDA and CMS record fields side by side, without recommending either medication.
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)] .
Briviact
Dilantin
Brivaracetam is a medicine used to treat partial-onset seizures. It helps to reduce the number of seizures you have.
Phenytoin injection is used to treat certain types of seizures. It can also prevent seizures during or after neurosurgery.
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.
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.
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 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.
- • Feeling sleepy or tired
- • Dizziness
- • Fatigue
- • Nausea or vomiting
No common side effects listed.
- Seizure 1,810
- Therapy Interrupted 280
- Overdose 233
- Fatigue 230
- Somnolence 216
- Drug Interaction 1,547
- Seizure 1,382
- Toxicity To Various Agents 1,353
- Convulsion 1,262
- Status Epilepticus 791
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.
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.
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.
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 2,769 submissions while phenytoin has 6,335. 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 represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for brivaracetam or phenytoin.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.