Understanding analgesic drugs.
D000700:Analgesics / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use; D006801:Humans; D009020:Morphine / Q000627:therapeutic use; D010146:Pain / Q000188:drug therapy*; D011957:Receptors, Opioid / Q000502:physiology
D000700:Analgesics; D011957:Receptors, Opioid; D009020:Morphine; D001241:Aspirin