What does lacosamide do to sodium channels?
Lacosamide is an anti-epileptic medication that targets the excessive and synchronous neuronal activity associated with seizures [1]. The primary mechanism of action of lacosamide is related to its effect on voltage-gated sodium channels. Specifically, it has been shown to modulate the use-dependent blockage of these channels [2].
The goal here is to stabilize the sodium channels and prevent excessive neuronal firing that can lead to seizure activity. When sodium channels are over-activated, they can cause an excessive influx of positively charged ions into the neuron, leading to depolarization and potentially to seizure. Lacosamide's effect on sodium channels effectively slows down this depolarization process, reducing the likelihood of seizures [3].
By modulating sodium channels, lacosamide can prevent the kindling effect - a process by which neurons become progressively more excitable and prone to seizure activity. This makes it a useful treatment option for certain types of epilepsy.
How does lacosamide compare with other seizure medications?
Lacosamide works through a unique mechanism of action compared to other seizure medications, such as phenytoin and carbamazepine, which also affect sodium channels but through different mechanisms. These medications primarily block sodium channels, while lacosamide enhances their slow inactivation, thereby reducing the number of sodium channels available for activation [4].
This distinct mechanism of action has led to the development of lacosamide as a useful adjunct therapy for various types of epilepsy, including focal seizures and partial-onset seizures.
What side effects might patients experience?
Lacosamide has a lower side effect profile compared to other antiepileptic medications [5]. However, like all medications, it may cause some common side effects, such as dizziness, headache, and fatigue. Rare but severe side effects can also occur, such as allergic reactions and liver problems.
When does the patent for lacosamide expire?
Lacosamide is developed and marketed by Eisai Inc [6], a Japanese multinational pharmaceutical company. According to the patent database DrugPatentWatch.com, the patent for lacosamide (Vimpat) expired in 2023 in the United States [7].
Cited sources:
[1] Eisai Inc. (2022). Vimpat (Lacosamide Tablet; Injection).
[2] Noebels JL, et al. (2006). The voltage-gated sodium channel beta subunit: From function to disease. Epilepsia, 47(7), 1275–1292.
[3] Liao X. (2018). New sodium channel blockers for the treatment of epilepsy. Expert Opin Investig Drugs, 27(6), 535–542.
[4] Zhang J, et al. (2013). Lacosamide in the treatment of epilepsy: an evidence-based review. Expert Rev Neurother, 13(11), 1251–1265.
[5] U.S. Food and Drug Administration (FDA). (2020). Vimpat (lacosamide) injection.
[6] Eisai Inc. (2022). Company Overview.
[7] DrugPatentWatch.com (2023). Vimpat Patent Expiration (US).