Comparing the pharmacology of lacosamide and levetiracetam
While both lacosamide (Vimpat) and levetiracetam (Keppra) are modern antiepileptic drugs (AEDs), they operate through distinct mechanisms to control seizures. Levetiracetam acts broadly by binding to the synaptic vesicle protein 2A (SV2A), a key protein involved in the release of neurotransmitters. In contrast, lacosamide selectively enhances the slow inactivation of voltage-gated sodium channels, helping to limit excessive neuronal firing during a seizure.
Indications for different seizure types
Levetiracetam's broad-spectrum action makes it effective for a wider range of seizure types, including partial-onset, myoclonic, and generalized tonic-clonic seizures. Lacosamide is primarily approved for partial-onset seizures and as an adjunctive therapy for primary generalized tonic-clonic seizures.
Notable differences in side effect profiles
Levetiracetam is often associated with neuropsychiatric side effects such as mood changes, irritability, and aggression. Other common side effects may include sleepiness and headaches. Lacosamide's common adverse effects are typically neurological, such as dizziness, headaches, and nausea. It also carries a risk of cardiac rhythm abnormalities.
Controlled substance status
Levetiracetam is not a controlled substance. Lacosamide, however, is classified as a Schedule V controlled substance in the United States, meaning it has a lower potential for abuse than Schedule IV drugs but is still subject to stricter regulations.
Cost and accessibility
Generic levetiracetam is generally more affordable than lacosamide, even with the availability of a generic version of lacosamide. Cost can be a significant factor in treatment adherence.
Important considerations for doctors and patients
Selecting between these medications involves considering seizure type, potential side effects, co-morbidities, drug interactions, cost, and treatment history. Levetiracetam may be preferred for its broad spectrum and affordability, while lacosamide offers an alternative, particularly for those with focal seizures or sensitivity to levetiracetam's behavioral effects.
Lacosamide vs. Levetiracetam: A comparison
| Feature | Lacosamide (Vimpat) | Levetiracetam (Keppra) |
|---|---|---|
| Mechanism of Action | Enhances slow inactivation of voltage-gated sodium channels. | Binds to the synaptic vesicle protein 2A (SV2A). |
| Indications | Primarily focal-onset seizures; adjunctive for generalized tonic-clonic. | Partial-onset, myoclonic, and generalized tonic-clonic seizures. |
| Side Effects | Dizziness, headache, nausea, abnormal heartbeats, fainting. | Mood changes, irritability, behavioral issues, sleepiness, weakness. |
| Controlled Status | Schedule V controlled substance. | Not a controlled substance. |
| Drug Interactions | Favorable profile with fewer significant interactions. | Potential interactions, though generally well-tolerated. |
| Cost | More expensive, even in generic form. | Generally more affordable due to wide generic availability. |
| Use in Special Populations | Effective in elderly with focal epilepsy. | Widely used, but behavioral effects in children are a known risk. |
Conclusion
Lacosamide and levetiracetam are distinct antiepileptic medications with different mechanisms, indications, side effects, and controlled substance statuses. Selection depends on individual patient factors. Levetiracetam's broad spectrum and affordability make it a common choice, while lacosamide is a valuable alternative, particularly for certain seizure types or in patients sensitive to levetiracetam's behavioral effects. Consultation with a healthcare provider is essential for effective treatment.
