Lacosamide (Vimpat®) for epilepsy

What is Lacosamide?

Epilepsy is not an easy condition to live with. The sudden unexpected onset of seizures makes one’s social life very difficult. However, it can be controlled with drug treatment. Though we have good drugs on the market such as levetiracetam or phenytoin, newer drugs are being discovered each year. Lacosamide is one of them. It was discovered in 1996 and approved by the US FDA in 2008. It was called Vimpat commercially, but recently since its patent expired, it is now available in the generic form, thus increasing its accessibility. Lacosamide is FDA approved for focal seizures in children 1 month of age and older, and as an add-on for primary generalized epilepsy in patients 4 years of age and older, as well as for status epilepticus. 

How does Lacosamide work and how is it given?

Epilepsy occurs when the neurons in your brain are hyper-excitable and suddenly send powerful uncontrolled impulses. The circuits in your brain depend on ion channels in the neurons. Lacosamide causes a slow inactivation of voltage-dependent sodium ion channels, thus preventing repetitive and powerful electrical activity. It also binds to the collapsin response mediator protein 2 (CRMP2) which is thought to play a role in causing epilepsy.

Lacosamide is given to patients as

• tablets
• oral solutions
• intravenous forms

The IV form is especially convenient for hospitals. The dose is generally 50 mg twice a day for one week, and it can be increased to 100 mg twice a day and can be increased further if tolerated, or a slower dose if side effects arise. In kidney or liver failure, Lacosamide is fine, however it is recommended that you take 75% of the normal dose. For patients on dialysis, it is recommended to retake an extra 50% of the dose after the dialysis procedure as the drug gets filtered out. So if you take 50 mg twice a day, take an extra 25 mg after each dialysis session.

What are the side effects of Lacosamide?

Common side effects of Lacosamide include

• dizziness
• nausea
• vertigo
• abnormal coordination
• ataxia

Most of which disappear with continued drug treatment. However the side effects may increase if it is used in combination with another sodium channel blocker such as phenytoin or carbamazepine. If you are at risk of heart conditions like arrhythmias, heart block, Brugada Syndrome or heart failure, it is better to monitor the patient with an EKG as the drug can elongate the PR interval in an EKG. There is also a risk of suicidal ideas emerging. However despite all of these, it is generally well tolerated by most patients.

Sometimes Lacosamide might not work if you do not adhere to the proper dosage instructions. This is alarming as it can lead to breakthrough seizures. Drugs may be wonderful, but they are nothing without discipline. Do not miss doses or take a lower dose. If you miss a dose, you should make it up right away during the day, or take double the dose at night. Make sure that you don’t give up too early, as it may take around 3 to 6 months to see the full effect. Even despite adhering to a perfect regimen, around 25% of people experience what is called as drug-resistant epilepsy, where they don’t answer to two or more anti-seizure drugs.

If you feel dizzy with Lacosamide, it is better not to drive vehicles for your own safety. Alcohol worsens the effects of dizziness and drowsiness.

It can also be used in older patients, however at a lower dose to prevent dizziness and other side effects.

Is Lacosamide safe in pregnancy and breastfeeding?

The good news is that the data so far shows that Lacosamide is safe in pregnancy, but more studies are needed to better understand the effects of Lacosamide in pregnancy.

Lacosamide is considered safe in breastfeeding, however the levels need to be monitored and the baby should be monitored for any effects such as drowsiness.

Can I stop Lacosamide if it is not working for me?

Like other anti-seizure drugs, we don’t suddenly stop giving Lacosamide because withdrawal seizures can occur, unless it’s an absolute allergic emergency. It is slowly tapered down over a few weeks to make the body more comfortable to the change.

Can I switch from Vimpat to a generic Lacosamide?

Though Lacosamide is now available in the generic form instead of purely as Vimpat, it is better to check the drug levels before and after switching brands to make sure that the transition is smooth.

What are the best cases to use Lacosamide in?

Since it is relatively safe, Lacosamide is used for patients who do not tolerate other anti-seizure medications such as levetiracetam, especially psychiatric patients, as the psychiatric side effects of Lacosamide are less. It is also beneficial in fast seizure control. 

Lacosamide is a good choice for patients who have focal epilepsy and generalized epilepsy as well, can be given in the hospital with fast titration and is available in IV form. Always watch for dizziness when you are on Lacosamide and watch for the effects on slowing the heart rate.