Anti-Seizure Medications

Anti-seizure medications (formerly also called “antiepileptic drugs”) are the cornerstone of epilepsy treatment. These medications don't “cure” epilepsy; but by suppressing the brain's excessive electrical activity, they prevent seizures from happening. This chapter introduces the most commonly used medications and what you need to know about them.

Read This First: How to Use This Chapter

The information below is for general introduction only; only your doctor can determine which medication, and at which dose, is right for your child.

Dose information is deliberately not given here, because the dose varies in every child according to age, weight, seizure type, and other medications.

Seeing something on a medication's “side effect” list does not mean your child will necessarily experience it. Most children tolerate the medications well. These lists are so you know what to watch for.

How Do the Medications Work?

Anti-seizure medications act through different mechanisms. Some slow down the ion channels (such as sodium or calcium channels) that let neurons fire excessively. Some strengthen the effect of GABA, the brain's natural calming agent. Others reduce the excitatory substances released from nerve endings. The mechanism by which a medication works determines which seizure type it will help with; this is exactly why the right seizure diagnosis means the right medication.

Commonly Used Anti-Seizure Medications

Below we introduce some of the medications commonly used in children, along with when they are preferred and the points to watch for. This list is not comprehensive and is constantly growing.

Levetiracetam

It is one of the most commonly used anti-seizure medications in children today. It is effective in both focal and some generalized seizures, allows quick dose adjustment, and has little interaction with the liver. Its most commonly reported side effects are behavioral ones: irritability, restlessness, outbursts of anger, and mood changes. These effects are not seen in most children, or are mild; but if you notice them, be sure to tell your doctor, because they can be reduced with a dose adjustment or a vitamin supplement (B6).

Valproic Acid (Sodium Valproate)

It is a powerful medication with a very broad range of action that has been in use for many years; it is quite effective in many generalized seizure types and in some syndromes. Its possible side effects include weight gain, changes in appetite, hair loss, tremor, and rarely effects on the liver and pancreas. A very important caution: valproic acid is a medication to be avoided when possible in girls and young women of childbearing age, because of the risk of harming the baby in pregnancy (teratogenicity). We cover this topic in detail in Chapter 44.

Lamotrigine

It is a medication used in both focal and generalized seizures that is usually well tolerated; it can also have positive effects on mood. Its most important feature is that it requires a very slow dose increase. The reason for this is the risk of a serious skin rash that can appear with a rapid increase. So if you see any rash in a child taking lamotrigine, contact your doctor without delay and follow the dose-increase schedule to the letter.

Carbamazepine and Oxcarbazepine

These are well-established medications that are effective especially in focal seizures. However, because they affect the sodium channel, they can worsen absence and myoclonic seizures; for this reason they are not used in these seizure types. Their side effects include drowsiness, balance problems, low sodium in the blood (especially with oxcarbazepine), and rarely skin reactions. In some backgrounds, a genetic test may be recommended before starting, to check for the risk of a serious skin reaction.

Ethosuximide

It is one of the first-choice medications especially in childhood absence epilepsy and is very effective in absence seizures. However, it works only in absence seizures; it has no effect on tonic-clonic seizures. Its side effects can include nausea, loss of appetite, and drowsiness.

Other and Newer Medications

Beyond these, many medications such as topiramate, zonisamide, lacosamide, clobazam, phenobarbital, phenytoin, vigabatrin, and gabapentin are used in specific situations. In addition, new molecules developed specifically for certain syndromes and options such as cannabidiol have joined the treatment in recent years (see Chapter 26). The choice of medication is made carefully, based on the seizure type, the syndrome, the child's age, other health conditions, and possible side effects.

Changing Brands and Generic Medications

When the pharmacy gives you a different brand of your medication, consult your doctor first. In some children, brand changes can affect seizure control.

Learn and write down the medication's active ingredient name; brand names vary from country to country and pharmacy to pharmacy, but the active ingredient is the same.

A Summary Comparison of Commonly Used Medications

The table below summarizes which seizure types some commonly used medications are preferred in and the points to watch for. This table is for general information only; the choice of medication is always specific to the child and is made by the doctor.

• Medication
• Commonly Used For
• Point to Watch For
• Levetiracetam
• Focal and generalized seizures
• Mood/behavior change; B6 may help
• Valproic acid
• Broad spectrum, generalized seizures
• Weight, liver; caution in girls
• Lamotrigine
• Focal and generalized seizures
• Very slow dose increase; watch for rash
• Carbamazepine/Oxcarbazepine
• Focal seizures
• Not used in absence/myoclonic; low sodium
• Ethosuximide
• Childhood absence epilepsy
• Effective only in absence; nausea
• Clobazam
• Add-on treatment, various types
• Drowsiness; effect may fade over time
• Topiramate
• Focal/generalized, add-on treatment
• Reduced appetite, word-finding difficulty, fluid intake

Medication Forms: Syrup, Tablet, Drops

Anti-seizure medications can come in different forms: syrup (suspension), tablet, capsule, chewable tablet, or granules. In young children, syrup or measurable liquid forms are usually preferred; as they grow, they may switch to tablets. With syrup forms, it is very important to shake the bottle well before each use and to measure the medication accurately with the measuring spoon/syringe provided; measuring with a kitchen spoon leads to the wrong dose. If tablets need to be split or crushed, ask your pharmacist whether that is appropriate for that medication; some tablets lose their effect when split.

Practical Ways Not to Miss Medication Times

• Tie the medication times to a daily routine (breakfast, brushing teeth, bedtime); this makes it harder to forget.
• Set a daily alarm on your phone or use a medication reminder app.
• Using a weekly pill box lets you see whether that day's dose has been given.
• As soon as you notice the medication running low, refill the prescription right away; keep a few days' supply on hand so the medication never runs out.
• If a caregiver or school is involved, clearly establish who is responsible for the medication, so a dose isn't given twice or not at all.

Don't Confuse Drug Resistance With “False Resistance”

If seizures continue, the problem is not always that the medication is ineffective. The most commonly overlooked cause is doses not being given regularly.

Be honest: if you are having difficulty sticking to the medication, share this with your doctor. This information prevents unnecessary medication changes and helps find the right solution.