What is a class of drugs that relieve pain called?

An analgesic or painkiller is any member of the group of drugs used to achieve analgesia, relief from pain.

Analgesic choice is also determined by the type of pain: For neuropathic pain, traditional analgesics are less effective, and there is often benefit from classes of drugs that are not normally considered analgesics, such as tricyclic antidepressants and anticonvulsants.

Analgesics are typically classified based on their mechanism of action.

Paracetamol, is a medication used to treat pain and fever. It is typically used for mild to moderate pain. In combination with opioid pain medication, paracetamol is now used for more severe pain such as cancer pain and after surgery.

Nonsteroidal anti-inflammatory drugs are a drug class that groups together drugs that decrease pain and lower fever and, in higher doses, decrease inflammation. The most prominent members of this group of drugs, aspirin, ibuprofen and naproxen.