Increased naloxone reversibility in fentanyl dose-dose discrimination.
Two groups of rats were trained to discriminate 0.04 mg/kg of fentanyl from saline (drug-saline discrimination) or from 0.02 mg/kg of fentanyl (dose-dose discrimination). The ED50 of naloxone for antagonizing the discriminative effects of 0.04 mg/kg fentanyl was 0.05 and 0.0062 mg/kg, respectively. This 8.1 fold difference in naloxone reversibility suggests that dose-dose discrimination yields higher pharmacological specificity than the commonly used drug-saline discrimination.
D000818:Animals; D004192:Discrimination, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005283:Fentanyl / Q000037:antagonists & inhibitors*; D005795:Generalization, Stimulus / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D009270:Naloxone; D005283:Fentanyl