Effectiveness of low-dose perampanel in focal epilepsy patients aged twelve or older in Southern China: an observational study

Why this study matters to families and patients

For people living with epilepsy, finding a medicine that calms seizures without causing troublesome side effects is a constant balancing act. This study from Southern China looked at how well small daily doses of the drug perampanel helped teenagers and adults with focal epilepsy control their seizures in everyday clinic settings, and which kinds of patients seemed to benefit the most.

A closer look at the people in the study

The research team followed 190 patients aged twelve or older who all had focal epilepsy, a form in which seizures start in one area of the brain. Most already had hard to treat epilepsy and had tried other drugs. Everyone received perampanel in addition to their usual medicines, but at relatively low daily doses of 2, 4, or 6 milligrams. Doctors chose the final long term dose for each person and then kept it steady for months, tracking how often seizures occurred, whether patients stayed on the drug, and which side effects appeared.

How well low doses cut seizure numbers

Across all three dose groups, seizure frequency dropped compared with the months before starting perampanel. After one year, the median seizure reduction reached 100 percent in the 2 milligram group, 91 percent in the 4 milligram group, and 82.5 percent in the 6 milligram group, meaning that many patients had far fewer seizures and some became seizure free. When the researchers looked at the share of patients whose seizures fell by at least half, they found rates between about 45 and 67 percent across the dose range. The overall differences between doses were not statistically strong, but there were hints that some subgroups responded better to the higher dose.

Who seemed to benefit the most

The team dug deeper into the data to see how factors such as how long a person had lived with epilepsy, brain scan findings, and the number of other seizure medicines used might shape response. People who had lived with epilepsy for less than five years tended to do better over the long term, regardless of the exact dose between 2 and 6 milligrams. Using fewer other antiseizure drugs at the same time was linked to a better early response at six months. Among patients with a longer disease history or only focal seizures without spread to both sides of the body, those taking 6 milligrams showed a higher chance of improvement than those on 2 milligrams.

Side effects and staying on treatment

Because perampanel can sometimes trigger mood or behavior changes, the study paid close attention to safety. Overall, side effects were reported in about one in five dose periods, and most were relatively mild, with dizziness the most common complaint and some psychiatric symptoms such as irritability and agitation. The lowest dose, 2 milligrams, had the fewest reported side effects, while 4 and 6 milligrams had slightly higher rates and more people who experienced more than one problem. Even so, the fraction of patients who had to stop the drug because of side effects remained below about one in seven across all doses, which is lower than in many earlier reports from Europe.

What this means for everyday care

To patients and families, the findings suggest that in this Southern Chinese population, modest daily doses of perampanel can provide meaningful seizure control with a tolerable safety profile. Starting with a low dose and using it early, either alone or added to just one other medicine, may offer a good balance between benefit and side effects, especially for people whose epilepsy is still in its first few years. For those with longer lasting or drug resistant epilepsy, somewhat higher low doses like 6 milligrams may be needed. Because this was an observational study rather than a strict drug trial, the authors caution that it cannot prove one dose is best, but it does support aiming for the lowest dose that keeps seizures in check over time.

Citation: Lu, X., Deng, Y., Shi, X. et al. Effectiveness of low-dose perampanel in focal epilepsy patients aged twelve or older in Southern China: an observational study. Sci Rep 16, 14826 (2026). https://doi.org/10.1038/s41598-026-43441-8

Keywords: epilepsy, focal seizures, perampanel, antiseizure medication, tolerability