This group comprises preparations used in the treatment of epilepsy and related conditions (e.g. seizures).
Combined preparations are classified at separate 5th levels using the corresponding 50-series.
The group is subdivided according to chemical structure.

Clonazepam is classified in this group.
All other benzodiazepines are classified as anxiolytics in N05B (e.g. diazepam) or hypnotics/sedatives in N05C (e.g. midazolam).