Lamotrigine vs levetiracetam (Keppra): seizure medicines compared
Lamotrigine (Lamictal) and levetiracetam (Keppra) are widely used seizure medicines. Levetiracetam can be started quickly and has few drug interactions but can affect mood; lamotrigine must be increased slowly because of a rare serious rash, and it also treats bipolar disorder.
Updated October 4, 2026
At a glance
- Starting
- Lamotrigine
- Slow increase over several weeks
- Levetiracetam
- Can start at an effective dose quickly
- Drug interactions
- Lamotrigine
- Several, including valproate and estrogen birth control
- Levetiracetam
- Very few
- Notable side effects
- Lamotrigine
- Rare serious rash, dizziness
- Levetiracetam
- Irritability, mood changes, tiredness
- Also used for
- Lamotrigine
- Bipolar disorder (maintenance)
- Levetiracetam
- Seizures only
- Generic
- Lamotrigine
- Yes
- Levetiracetam
- Yes
Lamotrigine Lamictal | Levetiracetam Keppra | |
|---|---|---|
| Starting | Slow increase over several weeks | Can start at an effective dose quickly |
| Drug interactions | Several, including valproate and estrogen birth control | Very few |
| Notable side effects | Rare serious rash, dizziness | Irritability, mood changes, tiredness |
| Also used for | Bipolar disorder (maintenance) | Seizures only |
| Generic | Yes | Yes |
Starting and speed
Levetiracetam can be started at a working dose within days, which helps when seizures need control quickly. Lamotrigine is increased slowly over about six weeks because starting too fast raises the risk of a rare, serious rash; after a gap of several days it is restarted low rather than at the usual dose.
Interactions
Levetiracetam has almost no drug interactions. Lamotrigine levels roughly double with valproate, so the dose is much lower, and fall with estrogen-containing birth control and during pregnancy, so levels may need checking. Some seizure medicines, such as carbamazepine and phenytoin, lower lamotrigine levels.
Side effects
Levetiracetam commonly causes tiredness and can cause irritability, aggression or low mood, which should be reported. Lamotrigine is often well tolerated, but any rash, especially with fever or mouth sores, needs prompt medical attention. Both carry a warning about suicidal thoughts, as all seizure medicines do.
Pregnancy and stopping
Both are among the seizure medicines with lower birth defect risks, which matters for people who may become pregnant; plans should be discussed in advance. Neither is stopped suddenly, because seizures can return.
Cost
Both are generics. Extended-release forms cost more, so ask for a quote on the exact form prescribed.
Missed doses
Take a missed dose when you remember unless the next one is near, and never double up. With lamotrigine, if you miss several days in a row, ask your prescriber before restarting, because restarting at the full dose raises the rash risk.
Questions for your prescriber
- Which suits my seizure type and other conditions?
- How do my other medicines or birth control affect it?
- What mood or skin changes should I report?
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Sources
Written by the Script Unlock editorial team from the sources above. It is general information, not advice for you or your pet; your prescriber decides which medicine is right.
Script Unlock is a marketplace that lets licensed pharmacies quote a cash price on your prescription. It does not prescribe, dispense or sell medication, does not process patient payments, and does not give medical advice. Always follow the instructions of your prescriber and pharmacist and read the medication guide supplied with your medicine.