In a very broad sense, an analgesic is a “painkiller,” so an analgesic is intended to work on the nervous system in order to relieve pain due to injury, muscle strain or overuse, or a disease state that causes nervous system difficulties. read more
In context|pharmacology|lang=en terms the difference between analgesic and tranquilizer is that analgesic is (pharmacology) any medicine, such as aspirin, that reduces pain without inducing unconsciousness while tranquilizer is (pharmacology) a drug used to reduce anxiety or tension; a sedative. read more
A painkiller refers to anything from aspirin and NSAIDs (acetaminophen, naproxen, etc.), all the way to opiate medications (hydrocodone, oxycodone, morphine, etc.), whereas a tranquilizer can refer to so-call minor ones, such as benzodiazepines, to major ones, which are in the antipsychotic classes of medications. read more