An<unk>  (colloquially known as a painkiller) is any member of the diverse group of drugs used to relieve pain (achieve<unk> .  The word<unk>  derives from Greek an- ("without") and -algia ("pain").<unk>  drugs act in various ways on the peripheral and central nervous systems; they include paracetamol (acetaminophen), the non-steroidal anti-inflammatory drugs (NSAIDs) such as the salicylates, narcotic drugs such as morphine, synthetic drugs with narcotic properties such as tramadol, and various others.  Some other classes of drugs not normally considered<unk> s are used to treat neuropathic pain syndromes; these include tricyclic antidepressants and anticonvulsants.
Analgesic
Steroid
Local anesthetic
Antimicrobial
Antibiotic
Mood stabilizer
Stimulant
Non-steroidal anti-inflammatory drug