Effects of haloperidol on the behavioral, subjective, cognitive, motor, and neuroendocrine effects of Delta-9-tetrahydrocannabinol in humans.
Psychopharmacology (Berl)
; 198(4): 587-603, 2008 Jul.
Article
em En
| MEDLINE
| ID: mdl-18228005
ABSTRACT
INTRODUCTION:
Cannabinoids produce a spectrum of effects in humans including euphoria, cognitive impairments, psychotomimetic effects, and perceptual alterations. The extent to which dopaminergic systems contribute to the effects of Delta-9-tetrahydrocannabinol (Delta-9-THC) remains unclear. This study evaluated whether pretreatment with a dopamine receptor antagonist altered the effects of Delta-9-THC in humans. MATERIALS ANDMETHODS:
In a 2-test-day double-blind study, 28 subjects including healthy subjects (n = 17) and frequent users of cannabis (n = 11) were administered active (0.057 mg/kg) or placebo oral haloperidol in random order followed 90 and 215 min later by fixed order intravenous administration of placebo (vehicle) and active (0.0286 mg/kg) Delta-9-THC, respectively.RESULTS:
Consistent with previous reports, intravenous Delta-9-THC produced psychotomimetic effects, perceptual alterations, and subjective effects including "high." Delta-9-THC also impaired verbal recall and attention. Haloperidol pretreatment did not reduce any of the behavioral effects of Delta-9-THC. Haloperidol worsened the immediate free and delayed free and cued recall deficits produced by Delta-9-THC. Haloperidol and Delta-9-THC worsened distractibility and vigilance. Neither drug impaired performance on a motor screening task, the Stockings of Cambridge task, or the delayed match to sample task. Frequent users had lower baseline plasma prolactin levels and blunted Delta-9-THC induced memory impairments.CONCLUSIONS:
The deleterious effects of haloperidol pretreatment on the cognitive effects of Delta-9-THC are consistent with the preclinical literature in suggesting crosstalk between DAergic and CBergic systems. However, it is unlikely that DA D(2) receptor mechanisms play a major role in mediating the psychotomimetic and perceptual altering effects of Delta-9-THC. Further investigation is warranted to understand the basis of the psychotomimetic effects of Delta-9-THC and to better understand the crosstalk between DAergic and CBergic systems.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Dronabinol
/
Antipsicóticos
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Comportamento
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Cognição
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Alucinógenos
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Haloperidol
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Atividade Motora
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Sistemas Neurossecretores
Tipo de estudo:
Clinical_trials
Limite:
Adolescent
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Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article