The present invention features compounds having the Formula (Ia) and (Ib) (e.g., a compound of any of Formulas ((Ia-2)-(Ia-21)), including other tautomers, stereoisomers, E/Z stereoisomers, prodrugs, pharmaceutically acceptable salts, and compositions thereof. The invention also features methods for treating or preventing pain (e.g., neuropathic pain), inflammation, or epilepsy in a patient by administering an effective amount of a compound of Formula (Ia) or (Ib). The invention also features a method for treating or preventing pain (e.g., neuropathic pain), inflammation, or epilepsy in a patient that includes administering to a patient in need thereof an effective amount of a compound of Formula (IIa) or (IIb) (e.g., a compound of any of Formulas ((IIa-2)-(IIa-6)). The compounds described herein (e.g., a compound of Formulas (Ia), (Ib), (IIa), or (IIb)) can also be used as anticonvulsants.