What is Lacosamide?
Lacosamide is an anticonvulsant medication used to control seizures in people with epilepsy [1.8.1]. It is approved by the FDA for treating partial-onset seizures and as an add-on therapy for primary generalized tonic-clonic seizures in patients of certain ages [1.8.4]. Marketed under the brand name Vimpat, lacosamide works by decreasing abnormal electrical activity in the brain [1.8.1]. It is available as an oral tablet, oral solution, and an intravenous (IV) solution [1.8.1]. As a Schedule V controlled substance, it has a low potential for misuse [1.10.1].
Common and Serious Side Effects
The most common side effects associated with lacosamide include dizziness, headache, nausea, double vision, and fatigue [1.9.3]. Dizziness is a frequent reason for discontinuation [1.9.3]. Less common side effects can include memory impairment, depression, and balance issues [1.9.1].
More serious potential side effects require immediate medical attention. These include:
- Cardiac Issues: Lacosamide can cause an irregular heartbeat, fainting (syncope), and, in rare cases, cardiac arrest. The risk is higher for those with existing heart conditions [1.9.2].
- Suicidal Thoughts: Like other antiepileptic drugs, lacosamide carries a warning for an increased risk of suicidal thoughts or behaviors, affecting about 1 in 500 patients [1.9.2].
- DRESS Syndrome: A rare but serious allergic reaction called Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) can affect multiple organs and is a medical emergency [1.9.1].
It is critical not to stop taking lacosamide suddenly, as this can lead to an increase in seizure frequency. Any discontinuation should be done gradually under a doctor's supervision [1.8.1].
Understanding the Drug Tier System
Prescription drug formularies, or lists of covered drugs, are typically divided into tiers. These tiers determine the patient's out-of-pocket cost for the medication [1.3.1]. While the structure can vary between insurance plans, a common system includes four or five tiers:
- Tier 1: This tier has the lowest copay and usually includes preferred generic drugs [1.3.1, 1.3.5].
- Tier 2: This tier has a medium copay and includes many preferred brand-name drugs and some higher-cost generics [1.3.5].
- Tier 3: With a higher copay, this tier often consists of non-preferred brand-name drugs for which a cheaper alternative exists [1.2.3].
- Tier 4: This tier typically includes high-cost medications, often called specialty drugs. These drugs may be used for complex or chronic conditions [1.3.3]. In some plans, this is the highest-cost tier, while others may have a Tier 5 for non-preferred specialty drugs [1.3.5, 1.2.3].
So, Is Lacosamide a Tier 4 Drug?
The answer is: it depends on the specific insurance plan. Medicare prescription drug plans frequently list lacosamide on Tier 4 of their formularies [1.2.2]. However, coverage under commercial plans varies. For example, some 2025 Cigna plans implement step therapy, requiring patients to try the generic lacosamide (a Step 1 product) before the brand-name Vimpat (a Step 2 product) is covered [1.5.1]. This implies that generic lacosamide is on a more preferred (and lower-cost) tier than the brand version.
The availability of generic lacosamide significantly impacts its tier placement and cost. The generic version is substantially cheaper than the brand-name Vimpat [1.4.1]. Insurers often place generics on lower tiers (like Tier 1 or 2) to encourage their use [1.2.4]. Therefore, while brand-name Vimpat might be a Tier 3 or 4 drug, generic lacosamide is likely to be on a lower, more affordable tier in many 2025 formularies.
Patients should always check their insurance plan's specific formulary to confirm the tier placement and cost for both generic lacosamide and brand-name Vimpat.
Lacosamide vs. Other Antiepileptic Drugs (AEDs)
Lacosamide is one of many options for treating epilepsy. It is considered a newer AED and differs from older drugs like carbamazepine or phenytoin because it acts on the slow inactivation state of sodium channels [1.10.2].
| Feature | Lacosamide (Vimpat) | Levetiracetam (Keppra) | Lamotrigine (Lamictal) |
|---|---|---|---|
| Mechanism | Enhances slow inactivation of sodium channels [1.10.2] | Binds to synaptic vesicle protein SV2A [1.10.3] | Blocks fast inactivation of sodium channels [1.10.2] |
| Primary Use | Partial-onset seizures, adjunctive for primary generalized tonic-clonic seizures [1.8.1] | Partial-onset, myoclonic, and generalized tonic-clonic seizures [1.10.1] | Partial and generalized seizures, Bipolar I disorder |
| Common Side Effects | Dizziness, headache, nausea, double vision [1.9.3] | Sleepiness, weakness, headache, mood changes [1.10.1] | Dizziness, headache, rash (can be serious), insomnia |
| Controlled Substance? | Yes, Schedule V [1.10.1] | No [1.10.1] | No |
| Serious Risk | Cardiac rhythm changes, syncope [1.9.2] | Mood and behavioral issues [1.10.1] | Serious skin rashes (Stevens-Johnson syndrome) |
Studies suggest that lacosamide can be a reasonable alternative to other AEDs like levetiracetam and valproate [1.10.4]. The choice of medication depends on the seizure type, patient's medical history, potential side effects, and cost.
Cost and Affordability
Without insurance, lacosamide can be very expensive. The average retail price for 60 tablets of generic 100mg lacosamide is over $1,000, while the brand-name Vimpat is even more [1.4.4]. However, there are ways to reduce this cost:
- Generic Version: Choosing generic lacosamide is the most effective way to lower costs. GoodRx coupons can bring the price down to as low as $27 for a month's supply [1.4.5].
- Insurance: Most insurance plans cover generic lacosamide, with copays varying based on the drug's tier [1.4.2].
- Patient Programs: The manufacturer, UCB, offers a direct-to-patient program for brand-name Vimpat for those without insurance coverage, allowing them to purchase the medication for a significantly reduced cash price [1.4.3].
Conclusion
Lacosamide's classification as a Tier 4 drug is most common under Medicare plans, but its tier can vary significantly across different insurance formularies, especially with the availability of a generic version [1.2.2]. Generic lacosamide is typically placed on a lower, more cost-effective tier than its brand-name counterpart, Vimpat. Due to its unique mechanism of action, lacosamide is an important therapeutic option for managing certain types of seizures, but its potential for cardiac side effects and dizziness must be considered. Patients should consult their doctor and review their insurance plan's specific 2025 formulary to understand their coverage and out-of-pocket costs.
For more information on epilepsy and its treatments, you can visit CURE Epilepsy.
