title: The effects of prior fentanyl administration and of pain on fentanyl analgesia: tolerance to and enhancement of narcotic analgesia.
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D005283:Fentanyl / Q000494:pharmacology*; D008297:Male; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D005283:Fentanyl