See the DrugPatentWatch profile for Lacosamide
Are lacosamide and lamotrigine ever used together?
Yes. Lacosamide (Vimpat) and lamotrigine (Lamictal) are commonly prescribed in combination for epilepsy because they work through different mechanisms. Using them together can help control seizures when one drug alone is not enough.
What do they do differently?
Lamotrigine reduces seizure activity by stabilizing neuronal membranes (it blocks voltage-gated sodium channels).
Lacosamide also affects sodium channels, but it has a different binding profile and is described as enhancing slow inactivation of sodium channels. Because both target sodium channels in different ways, the combination can provide additive seizure control for some patients.
Does the combination increase side effects?
Often, the side effects you may see are mostly the sum of each drug’s typical risks rather than one “new” interaction. Common issues that patients ask about include dizziness, sleepiness/fatigue, nausea, headache, and balance problems—especially if doses are increased too quickly.
Lamotrigine has a key safety issue: rash risk, including rare but serious rash (for example, Stevens-Johnson syndrome). Lamotrigine dosing is typically titrated slowly to reduce that risk.
Lacosamide can cause dizziness and problems with coordination (ataxia) in some people; dose changes can make these worse.
Is there a major drug-drug interaction?
A well-known, clinically important interaction is not routinely flagged between lacosamide and lamotrigine the way it is for some other antiseizure medicines. Still, clinicians adjust doses based on the rest of a person’s medication list, liver enzyme effects, kidney function, and seizure control history.
How should lamotrigine be started if it’s being combined?
Lamotrigine is usually started low and titrated gradually. This matters even more when combining with other antiseizure drugs, because the slow ramp is what lowers the chance of serious rash.
If you’re adding lamotrigine to an existing regimen (like lacosamide), the prescriber will set the titration schedule based on whether the patient is taking enzyme-inducing drugs (some other antiseizure medicines can change lamotrigine levels).
What if seizures aren’t controlled on the combination?
If seizure control is still poor, doctors may:
- adjust the lamotrigine and/or lacosamide dose toward target ranges,
- review adherence and triggers (sleep, alcohol, missed doses),
- check whether other medicines are affecting blood levels,
- consider switching one drug or adding a different class of antiseizure therapy.
What should patients watch for and report urgently?
Seek urgent medical care for:
- new rash or rash that spreads, involves mouth/eyes, or comes with fever or blistering (lamotrigine safety concern),
- fainting, severe dizziness, or new/worsening trouble walking (possible lacosamide side effects),
- signs of allergic reaction.
If you tell me the exact doses (mg) and whether you take any other antiseizure medicines (especially carbamazepine, phenytoin, phenobarbital, or primidone), I can explain how the dosing and titration usually changes.