ArticlePsychopharmacology2015
Self-administration of cocaine and remifentanil by monkeys under concurrent-access conditions.
Article in Psychopharmacology, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
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Who cites it
7 citing papers in PubMed.
- Polydrug abuse: Choice between drugs as a function of concurrent nonindependent ratio sizes.Journal of the experimental analysis of behavior · 2025Article
- Choice between food and cocaine or fentanyl reinforcers under fixed and variable schedules in female and male rhesus monkeys.Psychopharmacology · 2023Article
- Choice between food and cocaine reinforcers under fixed and variable schedules in female and male rhesus monkeys.Experimental and clinical psychopharmacology · 2023Article
- Bidirectional influence of heroin and cocaine escalation in persons with dual opioid and cocaine dependence diagnoses.Experimental and clinical psychopharmacology · 2022Article
- Modeling Stimulant and Opioid Co-use in Rats Provided Concurrent Access to Methamphetamine and Fentanyl.Frontiers in psychiatry · 2022Article
- One Is Not Enough: Understanding and Modeling Polysubstance Use.Frontiers in neuroscience · 2020Review
- Choice between variable and fixed cocaine injections in male rhesus monkeys.Psychopharmacology · 2017Article
Corrections and comments
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Authors and funding
3 authors.
Funding
Abstract
rationaleCocaine and opioids are often co-abused. Laboratory research has focused largely on the reinforcing effects of mixtures of drugs relative to the drugs alone. Less research has examined drug mixing by the subject under concurrent-access conditions.
objectiveSelf-administration of various doses of cocaine and remifentanil was examined under concurrent-access conditions. It was hypothesized that if cocaine and opioid combinations were more effective reinforcers than the single drugs, subjects would mix the two drugs by adjusting their responding to cocaine and an opioid alternative to maintain an optimal ratio of cocaine/remifentanil intake.
methodThree male rhesus monkeys were allowed to self-administer cocaine (0.05-0.2 mg/kg/inj) or saline on one lever and remifentanil (0.05-0.4 μg/kg/inj) or saline on the other lever under concurrent fixed-ratio (FR) 10 schedules. Daily sessions lasted 2 h, and there was a 1-s timeout after every 10-s injection.
resultsWhen saline and drug were concurrently available, responding on the saline-associated lever was low relative to the drug alternative. When cocaine and remifentanil were concurrently available, both drugs were self-administered above saline levels. Cocaine intake decreased, and remifentanil intake increased as a function of the remifentanil dose that was available. Conversely, cocaine intake and remifentanil intake did not change systematically as a function of the cocaine dose that was available.
conclusionMonkeys will mix cocaine and an opioid when the two drugs are available concurrently. However, there was no indication that monkeys titrated drug intake to maintain an optimal ratio of intake of the two compounds.
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Registered trials
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