An analgesic (colloquially known as painkiller) is any member of the diverse group of drugs used to relieve pain. Analgesic drugs include the nonsteroidal anti-inflammatory drugs (NSAIDs) such as the salicylates, narcotic drugs such as morphine, and synthetic drugs with narcotic properties such as tramadol. Other classes of drugs not normally considered analgesics are used to treat neuropathic pain syndromes; these include tricyclic antidepressants and anticonvulsants.