13 When Medication Isn’t Working
Finding out that your child’s seizures have not responded to medication is difficult news. It can feel like a setback, or like running out of options. It is neither. Most children in this situation still have real, effective paths forward, and understanding what “drug-resistant” actually means is the first step toward finding the right one.
13.1 What Does “Drug-Resistant Epilepsy” Mean?
Doctors use the term drug-resistant epilepsy when seizures have not been controlled after trying two appropriate antiseizure medications (ASMs), each at an adequate dose and for a fair length of time1. This definition was established by the International League Against Epilepsy (ILAE) and is now used consistently across epilepsy centres worldwide.
Two medications is a meaningful threshold. Research has shown that each new medication tried after the first two failures has a progressively lower chance of achieving full seizure control2. This does not mean further medications are useless, but it does mean that continuing to cycle through drugs alone is unlikely to be the answer, and that other options deserve serious consideration.
Roughly one in three people with epilepsy will develop drug-resistant epilepsy2. It is one of the most common and consequential challenges in epilepsy care.
13.2 Why Do Some Children Not Respond to Medication?
There is no single explanation for why some children respond to medications and others do not. Several factors are known to play a role.
The underlying cause of the epilepsy matters greatly. Children with a structural cause, such as a brain malformation or a scar from an injury or infection, are more likely to have drug-resistant epilepsy than children with genetic generalized epilepsies, many of which respond well to medication3. The epilepsy syndrome itself is also important. Some syndromes, such as Dravet syndrome or epilepsy associated with tuberous sclerosis complex, are known from the outset to carry a high risk of medication resistance.
In some cases, what looks like drug resistance turns out to have a different explanation. Before concluding that medications have truly failed, your epilepsy team will want to be sure of a few things: that the diagnosis of epilepsy is correct, that the right medication was chosen for the seizure type, that the doses were adequate, and that the medication was being taken consistently. These are not criticisms, they are important questions, because the answer changes the path forward.
If seizures are continuing despite medication, it is worth revisiting the diagnosis with your neurologist. Some events that look like seizures are not epileptic in origin. Getting the diagnosis right is the most important step before considering any treatment change.
13.3 What Happens Next?
When epilepsy is confirmed as drug-resistant, the conversation shifts from “which medication should we try next” to “what is the best overall treatment strategy for this child.” That is a broader question, and answering it well usually requires evaluation at a comprehensive epilepsy centre.
Several treatment paths exist beyond continuing to add or switch medications. Epilepsy surgery can offer seizure freedom for children whose seizures start from a single identifiable area of the brain. Dietary therapies, such as the ketogenic diet, help some children, particularly those with certain epilepsy syndromes. Neuromodulation devices, including vagus nerve stimulation, responsive neurostimulation, and deep brain stimulation, are options for children who are not candidates for resective surgery. Each works differently, but all aim to reduce seizure frequency by modulating abnormal electrical activity in the brain.
Newer and targeted medications continue to be developed. For some epilepsy syndromes, disease-specific treatments have become available in recent years. Fenfluramine (Fintepla) and cannabidiol (Epidiolex) are examples of medications developed specifically for Dravet syndrome and Lennox-Gastaut syndrome. If your child has a specific diagnosis, it is worth asking your neurologist whether any syndrome-specific treatments apply.
13.4 Staying Involved in Your Child’s Care
Drug-resistant epilepsy is a marathon, not a sprint, and the path forward often involves trying more than one approach over time. It can be exhausting and discouraging. At the same time, the options available today are meaningfully better than they were even a decade ago, and research continues to advance.
A few things help families navigate this period well. Keeping an accurate seizure diary gives your team the information they need to judge whether treatments are helping. Asking questions at every appointment, including whether there are clinical trials your child might qualify for, keeps you informed and engaged. And seeking a second opinion at a specialized epilepsy centre, if you have not already, is always appropriate when seizures remain uncontrolled.
If your child has tried two or more medications without adequate seizure control, ask your neurologist about referral to a Level 3 or Level 4 epilepsy centre. These centres are equipped to perform surgical evaluations and offer the full range of treatment options. Finding one near you is possible through the National Association of Epilepsy Centers at naec-epilepsy.org.
13.5 Key Takeaways
- Drug-resistant epilepsy is defined as seizures that continue after two appropriate medications have been tried at adequate doses1.
- About one in three people with epilepsy will have drug-resistant epilepsy. The cause of the epilepsy strongly influences the likelihood of medication resistance3.
- Before concluding that epilepsy is truly drug-resistant, it is important to confirm the diagnosis is correct and that medications were given a fair trial.
- Drug-resistant epilepsy is not untreatable. Surgery, dietary therapies, neurostimulation, and targeted medications are all options that can make a meaningful difference.
- Evaluation at a comprehensive epilepsy centre is an important step for any child whose seizures are not controlled by medication.