Which medication is classified as an analgesic?

The classification of a medication as an analgesic signifies its primary use in relieving pain. Tramadol fits this definition perfectly, as it is commonly prescribed for moderate to severe pain relief. It works by binding to the brain's opioid receptors and inhibiting the reuptake of neurotransmitters, effectively dampening the perception of pain.

In contrast, cyclobenzaprine is classified as a muscle relaxant, primarily used to relieve muscle spasms, rather than directly targeting pain. Azithromycin is an antibiotic, used to treat bacterial infections and has no analgesic properties. Dilantin, or phenytoin, is an anticonvulsant medication used to control seizures and is not classified as an analgesic either. Thus, Tramadol stands out as the medication specifically intended for pain relief within the given options.