Which anticonvulsant is most likely to elicit a generalized seizure if rapidly removed?

Phenobarbital is recognized as an anticonvulsant that is particularly associated with the risk of seizure recurrence when there is a rapid discontinuation. This medication works by enhancing the effects of the neurotransmitter GABA, which helps to stabilize neuronal activity.

When phenobarbital is taken for a prolonged period, the body adapts to its presence, leading to a certain level of dependence. Abruptly stopping it can lead to a rebound effect, whereby the decreased inhibitory tone from GABA results in excitatory neuronal activity, potentially triggering generalized seizures.

This evidence aligns with clinical observations that indicate a higher likelihood of withdrawal seizures when phenobarbital is suddenly removed, especially compared to other anticonvulsants listed. Other medications like phenytoin, carbamazepine, and valproate may have their own withdrawal effects, but they typically do not present the same heightened risk for generalized seizures upon rapid discontinuation as phenobarbital does.