Which medication, when used long-term for seizure management, is known to cause facial coarsening, excessive hair growth, gum enlargement, and bone softening?

Explanation

Phenytoin, a commonly used antiepileptic drug, is associated with side effects such as coarsening of facial features, hirsutism, gingival hyperplasia, and osteomalacia when used over extended periods. These adverse effects are less commonly seen with other anticonvulsants like valproate, carbamazepine, or ethosuximide.