Which of the following medications is an anti-epileptic?

Dilantin, also known by its generic name phenytoin, is classified as an anti-epileptic medication. It is primarily used to control seizures in patients with epilepsy and belongs to a group of drugs known as hydantoins. Dilantin works by stabilizing neuronal membranes and decreasing the excitability of the neurons in the brain, which helps to prevent seizure activity.

The other medications listed serve different therapeutic purposes. For instance, tramadol is an analgesic used to manage moderate to moderately severe pain. Cyclobenzaprine is a muscle relaxant commonly prescribed for muscle spasms. Azithromycin is an antibiotic used to treat various bacterial infections. Understanding the specific uses of each medication is key to applying pharmacological knowledge in practice, especially in differentiating between classes of drugs and their therapeutic indications.