Opioid drugs in chronic non-malignant pain?
D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D002908:Chronic Disease; D006801:Humans; D010146:Pain / Q000188:drug therapy*; D051381:Rats; D012646:Self Administration; D019966:Substance-Related Disorders / Q000517:prevention & control / Q000523:psychology
D000701:Analgesics, Opioid