dronedarone vs phenytoin

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

moderate Known Drug Interaction

Rifampin and Other CYP3A Inducers Avoid rifampin or other CYP3A inducers such as phenobarbital, carbamazepine, phenytoin, and St.

Drug Class
dronedarone Class III Antiarrhythmic
phenytoin Anticonvulsant (Hydantoin)
Type
dronedarone Prescription
phenytoin Prescription
Summary
dronedarone

Multaq is a medicine that helps lower the risk of needing to stay in the hospital for atrial fibrillation (AFib). It is for people who have a history of AFib and are currently in normal heart rhythm.

phenytoin

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

What It Treats
dronedarone

Multaq is used to lower the risk of hospitalization if you have atrial fibrillation (AFib). AFib is an irregular heartbeat. This medicine is for people who used to have AFib, but are now in a normal heart rhythm.

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
dronedarone

Multaq is an antiarrhythmic drug. It works by changing the electrical signals in the heart. This helps to keep your heart in a normal rhythm and prevent AFib from returning.

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
dronedarone
  • Diarrhea
  • Nausea
  • Abdominal pain
  • Vomiting
  • Feeling weak or tired
phenytoin

No common side effects listed.

FAERS Reports
dronedarone
  • Atrial Fibrillation 1,420
  • Dyspnoea 838
  • Fatigue 615
  • Diarrhoea 477
  • Nausea 472
phenytoin
  • Drug Interaction 1,547
  • Seizure 1,382
  • Toxicity To Various Agents 1,353
  • Convulsion 1,262
  • Status Epilepticus 791
Serious Warnings
dronedarone

Multaq can increase the risk of death, stroke, and heart failure in patients with severe heart failure or permanent AFib. You should not take this medicine if you have severe heart failure that recently required hospitalization or if you have permanent AFib and will not be converted to a normal heart rhythm.

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
dronedarone

Multaq can harm an unborn baby. If you are a woman who could become pregnant, use effective birth control while taking Multaq. Do not breastfeed while taking Multaq and for 5 days after your last dose.

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.

Also Compare, Nearby Drugs

How to Read This dronedarone vs phenytoin Comparison

dronedarone is classified in the Class III Antiarrhythmic 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, dronedarone has 3,822 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 moderate interaction flagged in FDA labeling, attributed to phenytoin causes your body to clear dronedarone out of your system too quickly, making the treatment less effective.. 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 dronedarone or phenytoin.

Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.