include  paracetamol  (para-acetylaminophenol, also known in the US as acetaminophen), the  non-steroidal anti-inflammatory drugs (NSAIDs) such as the  salicylates , and  opioid  drugs such as  morphine  and opium.. Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. It is the feeling