Opioids ease neuropathic pain, but...
D000701:Analgesics, Opioid / Q000009:adverse effects / Q000627:therapeutic use*; D002908:Chronic Disease; D004361:Drug Tolerance; D006801:Humans; D007981:Levorphanol / Q000009:adverse effects / Q000627:therapeutic use*; D009422:Nervous System Diseases / Q000188:drug therapy* / Q000209:etiology; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D016032:Randomized Controlled Trials as Topic
D000701:Analgesics, Opioid; D007981:Levorphanol