Psychopharmacology
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Randomized Controlled Trial Comparative Study
Miotic and subject-rated effects of therapeutic doses of tapentadol, tramadol, and hydromorphone in occasional opioid users.
Tapentadol is a novel analgesic that activates mu-opioid receptors and blocks norepinephrine reuptake. There is very little information available regarding the non-analgesic pharmacodynamic effects of tapentadol. ⋯ The highest tested dose of tapentadol produced a profile of positive effects comparable to that of hydromorphone, whereas tramadol produced positive and negative subject-rated effects. The mixed findings for tramadol are consistent with previous findings indicating that it has a distinct profile of effects relative to prototypic opioids. Future research should examine the effects of higher tapentadol doses, as well as the factors contributing to the different subject-rated profile of effects observed for tramadol relative to tapentadol and hydromorphone.
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Randomized Controlled Trial
Effects of three therapeutic doses of codeine/paracetamol on driving performance, a psychomotor vigilance test, and subjective feelings.
Some recent pharmacoepidemiological studies revealed an elevated risk of driving accidents after opioid analgesics uses. Among analgesics, codeine is often associated with paracetamol in numerous pharmaceutical specialties. ⋯ This study did not reveal any significant impairment in performance due to the three therapeutic doses used in healthy young volunteers. However, the relationships between drug blood concentration and behavioral measures suggest that an inter-subject variability in blood concentration may influence the power of the observed drug effect.
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Randomized Controlled Trial
Acute effects of THC on time perception in frequent and infrequent cannabis users.
Cannabinoids have been shown to alter time perception, but existing literature has several limitations. Few studies have included both time estimation and production tasks, few control for subvocal counting, most had small sample sizes, some did not record subjects' cannabis use, many tested only one dose, and used either oral or inhaled administration of Δ⁹-tetrahydrocannabinol (THC), leading to variable pharmacokinetics, and some used whole-plant cannabis containing cannabinoids other than THC. Our study attempted to address these limitations. ⋯ A psychoactive dose of THC increases internal clock speed as indicated by time overestimation and underproduction. This effect is not dose related and is blunted in chronic cannabis smokers who did not otherwise have altered baseline time perception.
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Randomized Controlled Trial
Human pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) after repeated doses taken 2 h apart.
3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is one of the most abused recreational drugs. Its usual pattern of misuse includes repeated doses taken over a short time period that could influence MDMA pharmacology and toxicity. ⋯ MDMA pharmacokinetics and metabolic disposition following two doses separated by 2 h show that the contribution of the first dose to the MDMA-induced mechanism-based metabolic inhibition was already apparent. The concentrations of MDMA after the second dose were slightly higher than expected. The effects on blood pressure and temperature after the second administration were slightly higher than those following the first, but for heart rate and subjective variables these were lower than expected considering the MDMA concentrations achieved, suggesting a possible tolerance phenomenon.
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Randomized Controlled Trial
Docosahexaenoic acid-concentrated fish oil supplementation in subjects with mild cognitive impairment (MCI): a 12-month randomised, double-blind, placebo-controlled trial.
Epidemiological studies have suggested a beneficial effect of fish oil supplementation in halting the initial progression of Alzheimer's disease. However, it remains unclear whether fish oil affects cognitive function in older people with mild cognitive impairment (MCI). ⋯ This study suggested the potential role of fish oil to improve memory function in MCI subjects. Studies with larger sample sizes, longer intervention periods, different fish oil dosages and genetic determinations should be investigated before definite recommendations can be made.