Experimental and clinical psychopharmacology
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Exp Clin Psychopharmacol · Apr 2018
Naltrexone maintenance fails to alter amphetamine effects on intracranial self-stimulation in rats.
Pharmacotherapy to treat stimulant use disorders continues to be an unmet medical need. Some evidence supports both the role of opioids in mediating abuse-related amphetamine effects and the potential utility of opioid antagonists as therapeutic candidates for treating amphetamine abuse. This study used intracranial self-stimulation (ICSS) to evaluate effects of exposure to and termination of naltrexone maintenance on rewarding amphetamine effects in an ICSS procedure in rats. ⋯ Additionally, dose-effect curves for morphine and amphetamine were determined again 24 hr after pump removal. Our results suggest that (a) exposure to and termination of naltrexone maintenance do not affect baseline ICSS responding, (b) naltrexone doses sufficient to antagonize morphine did not alter amphetamine or cocaine effects, and (c) termination of naltrexone treatment produced weak evidence for increased morphine sensitivity but no change in amphetamine effects. Our results do not support naltrexone as a pharmacotherapy for amphetamine and cocaine abuse and also suggest that termination from chronic naltrexone does not increase sensitivity to abuse-related morphine or amphetamine effects in ICSS. (PsycINFO Database Record
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Exp Clin Psychopharmacol · Apr 2018
An assessment of concurrent cannabidiol and Δ⁹-tetrahydrocannabinol administration in place aversion and taste avoidance conditioning.
Rising interest in medical marijuana has prompted research into its phytocannabinoid constituents, particularly Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). Coadministration of CBD with THC has been shown to modulate a number of THC's effects, including its negative stimulus properties (e.g., anxiety, paranoia, psychosis) in a clinical setting. The present series of experiments extended these analyses by examining the ability of CBD to impact the aversive effects of THC as assessed in a combined taste and place conditioning procedure. ⋯ Similar to the initial assessment, CBD had no effect on THC-induced place or taste conditioning at either dose ratio. These results may reflect the specific phytocannabinoid dose ratios examined or species differences in cannabinoid action. The current findings further suggest that altering CBD content in medicinal cannabis will likely have minimal effects in terms of tolerability. (PsycINFO Database Record