What is the difference between Levetiracetam Oral and Phenytoin?

Levetiracetam Oral and Phenytoin are both Anticonvulsants, so they work through the same broad mechanism. They differ in dosing, half-life, side-effect frequency, and how individual patients tolerate them. See the head-to-head sections below for the specifics.

Can Levetiracetam Oral and Phenytoin be used for the same conditions?

Both medications are prescribed for overlapping indications including See full prescribing information. Always verify with your prescriber and the current FDA label before switching.

Is Levetiracetam the same as Phenytoin?

No. Levetiracetam (Levetiracetam Oral) and Phenytoin (Phenytoin) are distinct medications. They are sometimes confused because of similar branding or because they treat overlapping conditions, but they have different active ingredients and different safety profiles.

Which has fewer side effects, Levetiracetam Oral or Phenytoin?

Side-effect frequency varies by individual. The side-effect comparison section on this page shows FAERS-reported events for each drug side by side. FAERS is voluntary reporting, so it reflects what patients and clinicians chose to report, not absolute population risk.

Can I switch from Levetiracetam Oral to Phenytoin?

Switching medications should always be done under prescriber supervision. The "patient stories" section on this page includes accounts from people who have made the switch and what their transition felt like, but those are individual experiences, not protocols.

Levetiracetam Oral vs Phenytoin

Compare Levetiracetam Oral (Levetiracetam) and Phenytoin (Phenytoin), clinical data, side effects, and patient experiences.

Levetiracetam Oral

Levetiracetam · Anticonvulsant

How it works

12.1 Mechanism of Action The precise mechanism(s) by which levetiracetam exerts its antiepileptic effect is unknown. A saturable and stereoselective neuronal binding site in rat br...

Approved for

See full prescribing information

OralTablet

Phenytoin

Phenytoin, Dilantin · Anticonvulsant

How it works

12.1 Mechanism of Action The precise mechanism by which phenytoin exerts its therapeutic effect has not been established but is thought to involve the voltage-dependent blockade of...

Approved for

1 INDICATIONS AND USAGE Phenytoin chewable tablets are indicated for the treatment of generalized tonic-clonic (grand mal) and complex partial (psychomotor

temporal lobe) seizures and prevention and treatment of seizures occurring during or following neurosurgery. ( 1 )

OralTablet

Quick Comparison

Levetiracetam OralPhenytoin

Drug Class

Anticonvulsant

Route

Oral

Half-Life

N/A

FDA Approved

N/A

Side Effect Frequency Comparison

Estimated frequency (%) based on clinical trial data

Side Effects

Levetiracetam Oral

Drug Not Working

>10%

Fatigue

1-10%

Drowsiness

0.1-1%

Falls

0.1-1%

Headache

0.1-1%

Dizziness

0.1-1%

Nausea

0.1-1%

Diarrhea

0.1-1%

Phenytoin

Drug Not Working

>10%

Falls

1-10%

Dizziness

1-10%

Headache

0.1-1%

Nausea

0.1-1%

Fatigue

0.1-1%

Fever

0.1-1%

Rash

0.1-1%

FDA Warnings

Levetiracetam Oral

5 WARNINGS AND PRECAUTIONS • Behavioral abnormalities including psychotic symptoms, suicidal ideation, irritability, and aggressive behavior have been observed; monitor patients for psychiatric signs and symptoms ( 5
3 ) • Serious Dermatological Reactions: Discontinue levetiracetam at the first sign of rash unless clearly not drug related (5
2 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including levetiracetam, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication
Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1

Phenytoin

5 WARNINGS AND PRECAUTIONS • Withdrawal Precipitated Seizure: May precipitate status epilepticus
2 ) • Serious Dermatologic Reactions: Discontinue phenytoin chewable tablets at the first sign of a rash, unless the rash is clearly not drug-related
2 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including phenytoin chewable tablets, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication
Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1

Clinical Trial Data

No head-to-head clinical studies found for Levetiracetam Oral vs Phenytoin.

Levetiracetam Oral vs Phenytoin: What You Should Know

Key Differences

Both Levetiracetam Oral and Phenytoin belong to the Anticonvulsant class. While they share a similar mechanism of action, differences in pharmacokinetics, dosing, and side effect profiles may make one more suitable than the other for individual patients.

Safety Considerations

Levetiracetam Oral carries 4 FDA warnings. Phenytoin carries 4 FDA warnings. Patients should discuss all warnings and contraindications with their healthcare provider before starting or switching medications..

This comparison is for informational purposes only. Always consult a qualified healthcare professional before making medication decisions.

Related Comparisons

Lacosamide vs Levetiracetam Oral→Levetiracetam Oral vs Pregabalin→Levetiracetam Oral vs Phenytoin Sodium→Carbamazepine vs Levetiracetam Oral→Levetiracetam Oral vs Zonisamide→Extended Phenytoin Sodium vs Levetiracetam Oral→

Primary sources

Every figure on this comparison links back to its primary source. See data sources and methodology for the full provenance trail.

Levetiracetam Oral: DailyMed label · FAERS adverse events · ClinicalTrials.gov
Phenytoin: DailyMed label · FAERS adverse events · ClinicalTrials.gov

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Levetiracetam Oral vs Phenytoin

Compare Levetiracetam Oral (Levetiracetam) and Phenytoin (Phenytoin), clinical data, side effects, and patient experiences.

Levetiracetam Oral

Levetiracetam · Anticonvulsant

How it works

12.1 Mechanism of Action The precise mechanism(s) by which levetiracetam exerts its antiepileptic effect is unknown. A saturable and stereoselective neuronal binding site in rat br...

Approved for

See full prescribing information

OralTablet

Phenytoin

Phenytoin, Dilantin · Anticonvulsant

How it works

12.1 Mechanism of Action The precise mechanism by which phenytoin exerts its therapeutic effect has not been established but is thought to involve the voltage-dependent blockade of...

Approved for

1 INDICATIONS AND USAGE Phenytoin chewable tablets are indicated for the treatment of generalized tonic-clonic (grand mal) and complex partial (psychomotor

temporal lobe) seizures and prevention and treatment of seizures occurring during or following neurosurgery. ( 1 )

OralTablet

Quick Comparison

Levetiracetam OralPhenytoin

Drug Class

Anticonvulsant

Route

Oral

Half-Life

N/A

FDA Approved

N/A

Side Effect Frequency Comparison

Estimated frequency (%) based on clinical trial data

Side Effects

Levetiracetam Oral

Drug Not Working

>10%

Fatigue

1-10%

Drowsiness

0.1-1%

Falls

0.1-1%

Headache

0.1-1%

Dizziness

0.1-1%

Nausea

0.1-1%

Diarrhea

0.1-1%

Phenytoin

Drug Not Working

>10%

Falls

1-10%

Dizziness

1-10%

Headache

0.1-1%

Nausea

0.1-1%

Fatigue

0.1-1%

Fever

0.1-1%

Rash

0.1-1%

FDA Warnings

Levetiracetam Oral

5 WARNINGS AND PRECAUTIONS • Behavioral abnormalities including psychotic symptoms, suicidal ideation, irritability, and aggressive behavior have been observed; monitor patients for psychiatric signs and symptoms ( 5
3 ) • Serious Dermatological Reactions: Discontinue levetiracetam at the first sign of rash unless clearly not drug related (5
2 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including levetiracetam, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication
Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1

Phenytoin

5 WARNINGS AND PRECAUTIONS • Withdrawal Precipitated Seizure: May precipitate status epilepticus
2 ) • Serious Dermatologic Reactions: Discontinue phenytoin chewable tablets at the first sign of a rash, unless the rash is clearly not drug-related
2 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including phenytoin chewable tablets, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication
Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1

Clinical Trial Data

No head-to-head clinical studies found for Levetiracetam Oral vs Phenytoin.

Levetiracetam Oral vs Phenytoin: What You Should Know

Key Differences

Safety Considerations

This comparison is for informational purposes only. Always consult a qualified healthcare professional before making medication decisions.