Good Drug Effect Research Articles

Safety pharmacology of acute psilocybin administration in healthy participants

Psilocybin is being studied for its therapeutic potential in various mental health disorders, such as depression, anxiety, and addiction. Initial studies suggested that psilocybin is generally safe when used under controlled conditions, but more research is needed to better understand its safety profile. We report safety pharmacology data from a pooled analysis of three randomized crossover studies that included 85 healthy participants and 113 single-dose administrations of psilocybin. Single oral doses included 15 mg, 20 mg, 25 mg, and 30 mg psilocybin dihydrate. We investigated subjective effects, blood pressure, heart rate, body temperature, acute and subacute adverse effects, reports of flashbacks, and liver and kidney function before and after the studies. The 20, 25, and 30 mg doses of psilocybin produced stronger effects than the 15 mg dose. Psilocybin at all doses induced higher “good drug effects” than “bad drug effects.” Only the 25 and 30 mg doses increased anxiety. Psilocybin elevated autonomic effects only moderately. Tachycardia (>100 beats/min) was observed with 7% of all psilocybin administrations. Body temperature >38° was reached in 7%, 9%, 17%, and 32% of the participants with the 15, 20, 25, and 30 mg doses, respectively. Kidney and liver function parameters were unaltered at the end of the study. Five participants (6%) reported transient flashback phenomena. No serious adverse reactions occurred. These findings suggest that a single administration of psilocybin is safe with regard to acute psychological and physical harm in healthy participants in a controlled research setting.

OR17-01 Novel Provocation Test With MDMA (‘Ecstasy’) Reveals Oxytocin Deficiency As A New Pituitary Entity In Patients With Central Diabetes Insipidus - A Randomized Placebo-Controlled Trial

Abstract Disclosure: C. Atila: None. F. Holze: None. R. Murugesu: None. N. Rommers: None. N. Hutter: None. N. Varghese: None. C.O. Sailer: None. A. Eckert: None. M. Heinrichs: None. M. Liechti: None. M. Christ-crain: None. Introduction: Despite adequate treatment, patients with arginine vasopressin deficiency (AVP-D), known as central diabetes insipidus (cDI), often report psychological symptoms such as heightened anxiety levels, difficulties describing emotions, and depressed mood. Given the anatomical proximity, disruptions of the hypothalamic-pituitary axis causing an AVP-D could also disturb the oxytocin (OXT) system. OXT regulates socio-emotional functioning, including fear reduction, attachment, emotion recognition, and empathy. Therefore, these psychological symptoms may be caused by an additional OXT deficiency. However, OXT deficiency has not been established as a pituitary entity, as no provocation test for OXT is currently available. Here, we aimed to investigate the OXT system stimulator 3,4-Methylenedioxymethamphetamine (MDMA, ‘ecstasy’) as a novel biochemical and psychoactive provocation test to reveal an OXT deficiency in patients with cDI. Methods: Randomized, placebo-controlled, double-blind, cross-over study in 15 patients with cDI and 15 matched healthy controls. Participants underwent a psychological baseline evaluation, including the assessment of anxiety levels using the State-Trait Anxiety Inventory (STAI), mood using the Beck’s Depression Inventory (BDI), and alexithymia using the Toronto Alexithymia Scale (TAS). Participants were randomized to receive either a single oral dose of MDMA (100 mg) or placebo first. OXT samples were collected at 0, 90, 120, 150, 180, and 300 minutes after drug intake. Subjective effects in response to MDMA were assessed throughout the experiment. The primary outcome was the area under the plasma OXT concentration curve (AUC) after MDMA intake. Results: Already at baseline, patients compared with healthy controls, showed significantly higher scores in anxiety (STAI: 41 points [IQR 34-48] vs. 28 points [24-31]; p=0.02), alexithymia (TAS: 47 points [38-59] vs. 30 points [29-37; p=0.04), and depression symptoms (BDI: 6 points [3-17] vs. 1 point [0-2]; p=0.04). In response to MDMA stimulation, in patients, there was only a minimal OXT change with 66 pg/ml [16-94], while in healthy controls, OXT increased by 658 pg/ml [355-914]. The AUC was 15.8 times (1485%), i.e., 85,678 pg/ml (95%-CI [-10,800 to -63,356], p<0.001), lower in patients compared with healthy controls. This lack of OXT in patients was associated with lower subjective effects such as ‘good drug effect,’ ‘feeling high,’ ‘satisfaction,’ ‘happy,’ ‘trust,’ ‘talkative,’ ‘openness,’ and ‘fear reduction’ compared with healthy controls. Conclusion: These results lay the groundwork for OXT deficiency as a hypothalamic-pituitary entity. In patients with cDI, this lack in OXT was associated with reduced pro-social, empathic, and anxiolytic effects. Presentation: Saturday, June 17, 2023

Perceived effects of cannabis: Generalizability of changes in driving performance

Objective The objective of this analysis was to determine the generalizability of the relationship between different samples of a driver’s perceived state after cannabis use and related performance while operating a motor vehicle. Methods Data were collected from 52 subjects in a study examining the effects of cannabis on driving performance. Data were analyzed using the SAS GLM Select procedure, using stepwise selection, with subjective effects, dosing condition (placebo vs. 6.18% delta-9-tetrahydrocannabinol [THC]), and driving context as independent measures. Correlation matrices of measures of driving performance against subjective responses and dosing condition used Pearson’s and Spearman’s test statistics, respectively. Results were compared to a prior study from a sample of 10 subjects. Results Subjective perceptions of acute cannabis impairment remain significant predictors of driving performance and explain individual variability in driving performance degradation as well as the data, beyond that which can be explained by acute use of cannabis alone. However, the significant subjective predictors of driving performance differ between the current and prior studies. To better understand these differences, correlations between subjective effects and performance measures were evaluated, which revealed that most correlations matched directionally (e.g., an increase in “good drug effect” was correlated with an increase in standard deviation of lane position [SDLP]). When there was a mismatch, 1 or more correlations were insignificant. Dosing condition and “stoned” were perfectly consistent; “high” and “sedated” contained 1 mismatch; and “anxious,” “good drug effect” and “restless” contained 3 or more mismatches. Conclusions The results indicate that across both studies, differences in the perceived effects of cannabis are reflected in changes in both lateral and longitudinal control beyond the acute effects of cannabis, which may help explain individual variability in response to acute intoxication. However, the generalizability of these findings is lacking, as shown by inconsistencies in when and where subjective effects were significant. Other factors such as frequency of use, usage type, the evolving profile of a cannabis user, as well as other individual differences should be considered to explain this additional variability.

The Relationship Between Circulating Endogenous Cannabinoids and the Effects of Smoked Cannabis.

Background: The endogenous cannabinoid system (ECS), including the endocannabinoids (eCBs), anandamide (AEA), and 2-arachidonoylglycerol (2-AG), plays an integral role in psychophysiological functions. Although frequent cannabis use is associated with adaptations in the ECS, the impact of acute smoked cannabis administration on circulating eCBs, and the relationship between cannabis effects and circulating eCBs are poorly understood. Methods: This study measured the plasma levels of AEA, 2-AG, and Δ-9-tetrahydrocannabinol (THC), subjective drug-effects ratings, and cardiovascular measures at baseline and 15-180 min after cannabis users (n=26) smoked 70% of a cannabis cigarette (5.6% THC). Results: Cannabis administration increased the ratings of intoxication, heart rate, and plasma THC levels relative to baseline. Although cannabis administration did not affect eCB levels relative to baseline, there was a significant positive correlation between baseline AEA levels and peak ratings of "High" and "Good Drug Effect." Further, baseline 2-AG levels negatively correlated with frequency of cannabis use (mean days/week) and with baseline THC metabolite levels. Conclusions: In a subset of heavy cannabis smokers: (1) more frequent cannabis use was associated with lower baseline 2-AG, and (2) those with lower AEA got less intoxicated after smoking cannabis. These findings contribute to a sparse literature on the interaction between endo- and phyto-cannabinoids. Future studies in participants with varied cannabis use patterns are needed to clarify the association between circulating eCBs and the abuse-related effects of cannabis, and to test whether baseline eCBs predict the intoxicating effects of cannabis and are a potential biomarker of cannabis tolerance.

Safety pharmacology of acute LSD administration in healthy subjects

RationaleLysergic acid diethylamide (LSD) is used in psychiatric and psychological research and investigated as a potential treatment for medical and psychiatric disorders, including depression, anxiety, and cluster headache.ObjectivesSafety data on clinical safety are available from small studies but not from larger samples. We report safety pharmacology data from a large pooled study sample on acute effects of LSD in healthy subjects.MethodsWe conducted a pooled analysis of four double-blind, randomized, placebo-controlled, crossover studies that included a total of 83 healthy subjects and 131 single-dose administrations of LSD. LSD administrations were matched to dose groups according to measured LSD peak plasma concentrations to adjust for uncertainties in the correct LSD dose in some studies. Single doses were 25, 50, 100, and 200 µg of LSD base. We investigated subjective effects (self-rated any drug effect, good drug effect, bad drug effect, and anxiety), blood pressure, heart rate, body temperature, duration of the acute LSD response, acute (12 h) and subacute (24 h) adverse effects, reports of flashbacks, and liver and kidney function before and after the studies.ResultsLSD dose-dependently increased subjective, physiologic, and adverse effects. The dose–response curves for the proportions of subjects with a certain amount of a subjective effect were steeper and reached a higher maximum for positive acute subjective effects compared with negative acute subjective effects. Maximal ratings of > 50% good drug effects were reached in 37%, 91%, 96%, and 91% of the LSD administrations at 25, 50, 100, and 200 µg. Maximal ratings of > 50% bad drug effects were reached in 0%, 9%, 27%, 31% at 25, 50, 100, and 200 µg, respectively. Mean ratings of Oceanic Boundlessness were 10%, 25%, 41%, and 44%, and mean ratings of Anxious Ego-Dissolution were 3.4%, 13%, 20%, and 22% at 25, 50, 100, and 200 µg, respectively. The physiologic effects of LSD were moderate. None of the subjects had systolic blood pressure > 180 mmHg at any time. Peak heart rate > 100 beats/min was observed in 0%, 6%, 20%, and 25% of the subjects at 25, 50, 100, and 200 µg, respectively. Maximal heart rates of 129 and 121 beats/min were observed in one subject at the 50 and 200 µg doses, respectively. Peak body temperature > 38° was observed in 0%, 11%, 7%, and 34% at 25, 50, 100, and 200 µg, respectively. Mean acute adverse effect scores on the List of Complaints were 5.6, 9.2, 12, and 13 at 25, 50, 100, and 200 µg, respectively. Kidney and liver function parameters were unaltered. Six subjects reported transient flashback phenomena.ConclusionsThe single-dose administration of LSD is safe in regard to acute psychological and physical harm in healthy subjects in a controlled research setting.

Pharmacokinetics and Pharmacodynamics of Lysergic Acid Diethylamide Microdoses in Healthy Participants.

"Microdoses" of lysergic acid diethylamide (LSD) are used recreationally to enhance mood and cognition. Increasing interest has also been seen in developing LSD into a medication. Therefore, we performed a pharmacokinetic-pharmacodynamic study using very low doses of LSD. Single doses of LSD base (5, 10, and 20µg) and placebo were administered in a double-blind, randomized, placebo-controlled crossover study in 23 healthy participants. Test days were separated by at least 5days. Plasma levels of LSD and subjective effects were assessed up to 6hours after administration. Pharmacokinetic parameters were determined using compartmental modeling. Concentration-subjective effect relationships were described using pharmacokinetic-pharmacodynamic modeling. Mean (95% confidence interval) maximal LSD concentrations were 151pg/mL (127-181), 279pg/mL (243-320), and 500pg/mL (413-607) after 5, 10, and 20µg LSD administration, respectively. Maximal concentrations were reached after 1.1hours. The mean elimination half-life was 2.7hours (1.5-6.2). The 5µg dose of LSD elicited no significant acute subjective effects. The 10µg dose of LSD significantly increased ratings of "under the influence" and "good drug effect" compared with placebo. These effects began an average of 1.1hours after 10µg LSD administration, peaked at 2.5hours, and ended at 5.1hours. The 20µg dose of LSD significantly increased ratings of "under the influence," "good drug effects," and "bad drug effects." LSD concentrations dose-proportionally increased at doses as low as 5-20µg and decreased with a half-life of 3hours. The threshold dose of LSD base for psychotropic effects was 10µg.

Acute dose-dependent effects of lysergic acid diethylamide in a double-blind placebo-controlled study in healthy subjects

Growing interest has been seen in using lysergic acid diethylamide (LSD) in psychiatric research and therapy. However, no modern studies have evaluated subjective and autonomic effects of different and pharmaceutically well-defined doses of LSD. We used a double-blind, randomized, placebo-controlled, crossover design in 16 healthy subjects (eight women, eight men) who underwent six 25 h sessions and received placebo, LSD (25, 50, 100, and 200 µg), and 200 µg LSD 1 h after administration of the serotonin 5-hydroxytryptamine-2A (5-HT2A) receptor antagonist ketanserin (40 mg). Test days were separated by at least 10 days. Outcome measures included self-rating scales that evaluated subjective effects, autonomic effects, adverse effects, plasma brain-derived neurotrophic factor levels, and pharmacokinetics up to 24 h. The pharmacokinetic-subjective response relationship was evaluated. LSD showed dose-proportional pharmacokinetics and first-order elimination and dose-dependently induced subjective responses starting at the 25 µg dose. A ceiling effect was observed for good drug effects at 100 µg. The 200 µg dose of LSD induced greater ego dissolution than the 100 µg dose and induced significant anxiety. The average duration of subjective effects increased from 6.7 to 11 h with increasing doses of 25–200 µg. LSD moderately increased blood pressure and heart rate. Ketanserin effectively prevented the response to 200 µg LSD. The LSD dose–response curve showed a ceiling effect for subjective good effects, and ego dissolution and anxiety increased further at a dose above 100 µg. These results may assist with dose finding for future LSD research. The full psychedelic effects of LSD are primarily mediated by serotonin 5-HT2A receptor activation.

Distinct acute effects of LSD, MDMA, and d-amphetamine in healthy subjects

Lysergic acid diethylamide (LSD) is a classic psychedelic, 3,4-methylenedioxymethamphetamine (MDMA) is an empathogen, and d-amphetamine is a classic stimulant. All three substances are used recreationally. LSD and MDMA are being investigated as medications to assist psychotherapy, and d-amphetamine is used for the treatment of attention-deficit/hyperactivity disorder. All three substances induce distinct acute subjective effects. However, differences in acute responses to these prototypical psychoactive substances have not been characterized in a controlled study. We investigated the acute autonomic, subjective, and endocrine effects of single doses of LSD (0.1 mg), MDMA (125 mg), d-amphetamine (40 mg), and placebo in a randomized, double-blind, cross-over study in 28 healthy subjects. All of the substances produced comparable increases in hemodynamic effects, body temperature, and pupil size, indicating equivalent autonomic responses at the doses used. LSD and MDMA increased heart rate more than d-amphetamine, and d-amphetamine increased blood pressure more than LSD and MDMA. LSD induced significantly higher ratings on the 5 Dimensions of Altered States of Consciousness scale and Mystical Experience Questionnaire than MDMA and d-amphetamine. LSD also produced greater subjective drug effects, ego dissolution, introversion, emotional excitation, anxiety, and inactivity than MDMA and d-amphetamine. LSD also induced greater impairments in subjective ratings of concentration, sense of time, and speed of thinking compared with MDMA and d-amphetamine. MDMA produced greater ratings of good drug effects, liking, high, and ego dissolution compared with d-amphetamine. d-Amphetamine increased ratings of activity and concentration compared with LSD. MDMA but not LSD or d-amphetamine increased plasma concentrations of oxytocin. None of the substances altered plasma concentrations of brain-derived neurotrophic factor. These results indicate clearly distinct acute effects of LSD, MDMA, and d-amphetamine and may assist the dose-finding in substance-assisted psychotherapy research.

Drug liking and wanting, not impulsive action or reflection is increased by 4-fluoroamphetamine

BackgroundNew psychoactive substances (NPS) are chemical analogues designed to mimic the effects of various classic recreational drugs of abuse including MDMA, LSD, and cannabis. NPS use is associated with concern about the acute and longer-term effects particular substances might have, with abuse and addiction as potential consequences. Impulsivity and sensitivity to the rewarding effects of drugs have been considered as risk factors for drug abuse. In light of the popularity of 4-fluoroamphetamine (4-FA), it is important to assess whether 4-FA can lead to subjective drug liking and wanting, and impulsive behavior, all factors contributing to the abuse likelihood of a substance.MethodsA placebo-controlled 2-way crossover study in 12 healthy poly-drug using participants was conducted to test subjective and behavioral effects of 4-FA (100 mg). 4-FA concentrations were determined in serum up to 12 h after administration and two impulsivity tasks and two drug experience questionnaires assessing drug liking and wanting, and good and bad drug effect, were administered between 1 and 11 h post-administration.ResultsFindings showed that 4-FA did not affect impulsive behavior. Self-ratings of drug liking and wanting and good drug effect were increased 1 h after administration; this effect was absent 11 h after drug intake.Discussion and conclusionTo conclude, 4-FA (single dose) increased self-rated liking and wanting, which is known to contribute to the abuse likelihood of a substance; however, it left another factor impulsive behavior unaffected. It has to be noted that the current picture is limited and might change with increased sample size, and/or different 4-FA doses.Clinical trial registrationTrial acronym: 4-FA. URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6164. Registration number: NTR6164 (Dutch clinical trial registry number).

Intranasal abuse potential of an abuse-deterrent oxycodone formulation compared to oxycodone immediate release and placebo in nondependent, recreational opioid users

To assess the intranasal (IN) human abuse potential of ELI-200, a novel immediate-release (IR) oxycodone formulation containing sequestered naltrexone. Randomized, double-blind, double-dummy, active and placebo-controlled, five-way crossover study. Pharmacodynamics, safety, and pharmacokinetics (PKs) were evaluated for up to 36 hours postdose. Single site in Canada (INC Research Toronto). Healthy male and female nondependent recreational opioid users underwent a naloxone challenge and drug discrimination qualification test. Single IN dose of ground ELI-200 (30-mg oxycodone hydrochloride [HCl]/3-mg naltrexone HCl), crushed 30-mg oxycodone HCl IR (Roxicodone®), placebo, fixed placebo, and single oral dose of intact ELI-200 (30mg/3mg). Peak effect (Emax) for bipolar Drug Liking (0-100 point visual analog scale). Of the 44 randomized subjects, 37 completed all five treatment periods. All active treatments showed significantly higher (p<0.001) median Drug Liking Emax relative to placebo. Significant reductions (p<0.001) in median Drug Liking [Emax] were observed for IN ELI-200 [56.0] compared to IN oxycodone IR [100.0]. Secondary positive or objective measures (High, Good Drug Effects, Overall Drug Liking, Take Drug Again, and maximum pupil constriction) showed significantly lower Emax for IN ELI-200 (p<0.001) compared to IN oxycodone IR. IN administration of ELI-200 demonstrated significantly decreased effects on subjective and physiologic measures, and greater nasal irritation, compared to IN oxycodone IR. These findings, along with the PK profile of naltrexone, demonstrated that when ELI-200 capsules were ground and administered intranasally, the naltrexone component was rapidly released and conferred meaningful abuse-deterrent properties.

Human abuse potential of brivaracetam in healthy recreational central nervous system depressant users

BackgroundBrivaracetam is a new antiepileptic drug indicated for adjunctive treatment of focal seizures in adults at a dose of 50–200mg/day taken in two equal doses. The objective of this study was to evaluate the abuse potential of brivaracetam compared with alprazolam (positive control), placebo, and levetiracetam. MethodsThis was a randomized, double-blind, triple-dummy, crossover study in healthy male and female recreational central nervous system (CNS) depressant users aged 18–55years, who could distinguish between the subjective effects of alprazolam 2mg and placebo. All participants received single doses of brivaracetam (50 [therapeutic dose], 200, 1000mg [supratherapeutic doses]), alprazolam (1.5, 3mg), placebo, and levetiracetam (4000mg) in random order each separated by 7–10days. Subjective Visual Analogue Scales (VAS) and Addiction Research Center Inventory (ARCI) scales were completed at intervals up to 24h postdose. Primary endpoints were Drug Liking (at this moment) VAS, Overall Drug Liking VAS, Feeling High VAS, and ARCI Pentobarbital Chlorpromazine Alcohol Group (PCAG, sedation) maximum effect (Emax). Maximum effect values on each scale were analyzed using a mixed-effect model (per protocol population, N=44). ResultsThe maximum effect for both alprazolam doses was significantly greater versus placebo for six designated endpoints, confirming study validity. Drug Liking (at this moment) VAS Emax was significantly lower for brivaracetam 50mg than alprazolam (both doses); there were no significant differences between brivaracetam 200mg and alprazolam (both doses), and brivaracetam 1000mg and alprazolam 1.5mg. Brivaracetam 1000mg (supratherapeutic single dose) had significantly higher Drug Liking (at this moment) VAS Emax than alprazolam 3mg. Overall, Drug Liking VAS Emax for brivaracetam 50 and 200mg was not significantly different from alprazolam (both doses). Brivaracetam 1000mg had significantly higher Overall Drug Liking VAS Emax than alprazolam 1.5mg, but was not significantly different from alprazolam 3mg. Feeling High VAS Emax was lower versus alprazolam with brivaracetam 50 and 200mg, while brivaracetam 1000mg was comparable with alprazolam (both doses). Addiction Research Center Inventory PCAG Emax for brivaracetam (all doses) was significantly lower than alprazolam (both doses). On the secondary/supportive endpoints, compared with alprazolam, brivaracetam had fewer positive effects (ARCI Morphine Benzedrine Group [euphoria]; Good Drug Effects VAS [50mg]) and fewer negative effects (Bad Drug Effects VAS; ARCI Lysergic Acid Diethylamide [dysphoria]). Brivaracetam was not significantly different from alprazolam for Take Drug Again VAS (50, 200mg). For most endpoints, brivaracetam (50–200mg) was not significantly different from levetiracetam (4000mg). ConclusionThis study in healthy recreational CNS depressant users showed that single doses of brivaracetam 50mg (therapeutic single dose) had lower sedative, positive, and negative drug effects than alprazolam, while brivaracetam 200 and 1000mg (supratherapeutic single doses) were more similar to alprazolam. The subjective profile of brivaracetam appeared to be similar to that of levetiracetam, but further evaluation using a range of levetiracetam doses would be needed to confirm similar abuse potential.

Direct comparison of the acute subjective, emotional, autonomic, and endocrine effects of MDMA, methylphenidate, and modafinil in healthy subjects

Rationale3,4-Methylenedioxymethamphetamine (MDMA) is used recreationally and investigated as an adjunct to psychotherapy. Methylphenidate and modafinil are psychostimulants that are used to treat attention-deficit/hyperactivity disorder and narcolepsy, respectively, but they are also misused as cognitive enhancers. Little is known about differences in the acute effects of equally cardiostimulant doses of these stimulant-type substances compared directly within the same subjects.MethodsWe investigated the acute autonomic, subjective, endocrine, and emotional effects of single doses of MDMA (125 mg), methylphenidate (60 mg), modafinil (600 mg), and placebo in a double-blind, cross-over study in 24 healthy participants. Acute drug effects were tested using psychometric scales, the Facial Emotion Recognition Task (FERT), and the Sexual Arousal and Desire Inventory (SADI).ResultsAll active drugs produced comparable hemodynamic and adverse effects. MDMA produced greater increases in pupil dilation, subjective good drug effects, drug liking, happiness, trust, well-being, and alterations in consciousness than methylphenidate or modafinil. Only MDMA reduced subjective anxiety and impaired fear recognition and led to misclassifications of emotions as happy on the FERT. On the SADI, only MDMA produced sexual arousal-like effects. Only MDMA produced marked increases in cortisol, prolactin, and oxytocin. In contrast to MDMA, methylphenidate increased subjective anxiety, and methylphenidate and modafinil increased misclassifications of emotions as angry on the FERT. Modafinil had no significant subjective drug effects but significant sympathomimetic and adverse effects.ConclusionsMDMA induced subjective, emotional, sexual, and endocrine effects that were clearly distinct from those of methylphenidate and modafinil at the doses used.

Safety pharmacology of acute MDMA administration in healthy subjects.

3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) is being investigated in MDMA-assisted psychotherapy. The present study characterized the safety pharmacology of single-dose administrations of MDMA (75 or 125 mg) using data from nine double-blind, placebo-controlled, crossover studies performed in the same laboratory in a total of 166 healthy subjects. The duration of the subjective effects was 4.2 ± 1.3 h (range: 1.4-8.2 h). The 125 mg dose of MDMA produced greater 'good drug effect' ratings than 75 mg. MDMA produced moderate and transient 'bad drug effect' ratings, which were greater in women than in men. MDMA increased systolic blood pressure to >160 mmHg, heart rate >100 beats/min, and body temperature >38°C in 33%, 29% and 19% of the subjects, respectively. These proportions of subjects with hypertension (>160 mmHg), tachycardia, and body temperature >38°C were all significantly greater after 125 mg MDMA compared with the 75 mg dose. Acute and subacute adverse effects of MDMA as assessed by the List of Complaints were dose-dependent and more frequent in females. MDMA did not affect liver or kidney function at EOS 29 ± 22 days after use. No serious adverse events occurred. In conclusion, MDMA produced predominantly acute positive subjective drug effects. Bad subjective drug effects and other adverse effects were significantly more common in women. MDMA administration was overall safe in physically and psychiatrically healthy subjects and in a medical setting. However, the risks of MDMA are likely higher in patients with cardiovascular disease and remain to be investigated in patients with psychiatric disorders.

Sex-dependent effects of cannabis-induced analgesia

BackgroundPreclinical studies demonstrate that cannabinoid-mediated antinociceptive effects vary according to sex; it is unknown if these findings extend to humans. MethodsThis retrospective analysis compared the analgesic, subjective and physiological effects of active cannabis (3.56–5.60% THC) and inactive cannabis (0.00% THC) in male (N=21) and female (N=21) cannabis smokers under double-blind, placebo-controlled conditions. Pain response was measured using the Cold-Pressor Test (CPT). Participants immersed their hand in cold water (4°C); times to report pain (pain sensitivity) and withdraw the hand (pain tolerance) were recorded. Subjective drug ratings were also measured. ResultsAmong men, active cannabis significantly decreased pain sensitivity relative to inactive cannabis (p<0.01). In women, active cannabis failed to decrease pain sensitivity relative to inactive. Active cannabis increased pain tolerance in both men women immediately after smoking (p<0.001); a trend was observed for differences between men and women (p<0.10). Active cannabis also increased subjective ratings of cannabis associated with abuse liability (‘Take again,’ ‘Liking,’ ‘Good drug effect’), drug strength, and ‘High’ relative to inactive in both men and women (p<0.01). ConclusionsThese results indicate that in cannabis smokers, men exhibit greater cannabis-induced analgesia relative to women. These sex-dependent differences are independent of cannabis-elicited subjective effects associated with abuse-liability, which were consistent between men and women. As such, sex-dependent differences in cannabis’s analgesic effects are an important consideration that warrants further investigation when considering the potential therapeutic effects of cannabinoids for pain relief.

An Exploratory Human Laboratory Experiment Evaluating Vaporized Cannabis in the Treatment of Neuropathic Pain From Spinal Cord Injury and Disease.

Using 8-hour human laboratory experiments, we evaluated the analgesic efficacy of vaporized cannabis in patients with neuropathic pain related to injury or disease of the spinal cord, most of whom were experiencing pain despite traditional treatment. After obtaining baseline data, 42 participants underwent a standardized procedure for inhaling 4 puffs of vaporized cannabis containing either placebo, 2.9%, or 6.7% delta 9-THC on 3 separate occasions. A second dosing occurred 3hours later; participants chose to inhale 4 to 8 puffs. This flexible dosing was used to attempt to reduce the placebo effect. Using an 11-point numerical pain intensity rating scale as the primary outcome, a mixed effects linear regression model showed a significant analgesic response for vaporized cannabis. When subjective and psychoactive side effects (eg, good drug effect,feeling high, etc) were added as covariates to the model, the reduction in pain intensity remained significant above and beyond any effect of these measures (all P<.0004). Psychoactive and subjective effects were dose-dependent. Measurement of neuropsychological performance proved challenging because of various disabilities in the population studied. Because the 2 active doses did not significantly differ from each other in terms of analgesic potency, the lower dose appears to offer the best risk-benefit ratio in patients with neuropathic pain associated with injury or disease of the spinal cord. A crossover, randomized, placebo-controlled human laboratory experiment involving administration of vaporized cannabis was performed in patients with neuropathic pain related to spinalcord injury and disease. This study supports consideration of future research that would include longer duration studies over weeks to months to evaluate the efficacy of medicinal cannabis in patients with central neuropathic pain.

Pharmacodynamic effects and relationships to plasma and oral fluid pharmacokinetics after intravenous cocaine administration

BackgroundNo controlled cocaine administration data describe cocaine and metabolite disposition in oral fluid (OF) collected with commercially-available collection devices, OF-plasma ratios, and pharmacodynamic relationships with plasma and OF cocaine and metabolite concentrations. MethodsEleven healthy, cocaine-using adults received 25mg intravenous cocaine. Physiological and subjective effects (visual analogue scales), and plasma were collected one hour prior, and up to 21h post-dose. OF was collected with the Quantisal™ device up to 69h post-dose. Cocaine, benzoylecgonine (BE) and ecgonine methyl ester were quantified in plasma by liquid chromatography-tandem mass spectrometry; cocaine and BE were quantified in OF by two dimensional-gas chromatography-mass spectrometry. ResultsIncreases in heart rate, blood pressure and positive subjective effects occurred within the first 15min, persisting up to 1h (“Rush”), with clockwise hysteresis observed for plasma and OF concentrations and some subjective measures. Peak subjective effects (“Rush,” “Good drug effect” and “Bad drug effect”) occurred prior to peak OF cocaine concentration, whereas observed peak plasma concentrations and subjective measures occurred simultaneously, most likely due to significantly earlier plasma Tmax compared to OF Tmax.Tlast was generally longer in OF (12.5h cocaine; 33.0h BE) than plasma (9.5h cocaine; >21h BE, cutoffs 1μg/L); 8 and 10μg/L OF cocaine confirmatory cutoffs yielded detection times similar to cocaine’s impairing effects, suggesting usefulness for DUID testing. ConclusionsOF offers advantages as an alternative matrix to blood and plasma for identifying cocaine intake, defining pharmacokinetic parameters at different confirmation cutoffs, and aiding different drug testing programs to best achieve their monitoring goals.

The effects of pioglitazone, a PPARγ receptor agonist, on the abuse liability of oxycodone among nondependent opioid users

AimsActivation of PPARγ by pioglitazone (PIO) has shown some efficacy in attenuating addictive-like responses in laboratory animals. The ability of PIO to alter the effects of opioids in humans has not been characterized in a controlled laboratory setting. The proposed investigation sought to examine the effects of PIO on the subjective, analgesic, physiological and cognitive effects of oxycodone (OXY). MethodsDuring this investigation, nondependent prescription opioid abusers (N=17 completers) were maintained for 2–3weeks on ascending daily doses of PIO (0mg, 15mg, 45mg) prior to completing a laboratory session assessing the aforementioned effects of OXY [using a within-session cumulative dosing procedure (0, 10, and 20mg, cumulative dose=30mg)]. ResultsOXY produced typical mu opioid agonist effects: miosis, decreased pain perception, and decreased respiratory rate. OXY also produced dose-dependent increases in positive subjective responses. Yet, ratings such as: drug “liking,” “high,” and “good drug effect,” were not significantly altered as a function of PIO maintenance dose. DiscussionThese data suggest that PIO may not be useful for reducing the abuse liability of OXY. These data were obtained with a sample of nondependent opioid users and therefore may not be applicable to dependent populations or to other opioids. Although PIO failed to alter the abuse liability of OXY, the interaction between glia and opioid receptors is not well understood so the possibility remains that medications that interact with glia in other ways may show more promise.

Correlation of Subjective Effects with Systemic Opioid Exposure from Fixed-Dose Combinations of Oxycodone/Acetaminophen in Recreational Users of Prescription Drugs.

To correlate abuse-related pharmacodynamic measures and pharmacokinetic measures after administering immediate-release/extended-release and immediate-release oxycodone/acetaminophen fixed-dose combination analgesicsDesign. Randomized, double-blind, active- and placebo-controlled, 7-way crossover studySetting. Contract research organizationSubjects. Nondependent recreational users of prescription opioids. Participants received single doses of intact immediate-release/extended-release and immediate-release oxycodone/acetaminophen 15/650 mg, intact immediate-release/extended-release and immediate-release oxycodone/acetaminophen 30/1,300 mg, crushed immediate-release/extended-release and immediate-release oxycodone/acetaminophen 30/1,300 mg, and placebo. Measures of pharmacodynamics (pupillometry, drug liking, drug high, good drug effects) and pharmacokinetics were assessed predose and up to 24 hours postdose, and correlations between pharmacokinetic parameters and pharmacodynamic data were explored. Of 61 participants, 55 completed all 7 treatments. Intact immediate-release/extended-release oxycodone/acetaminophen produced 50% lower oxycodone peak plasma concentration (Cmax) than immediate-release oxycodone/acetaminophen. Median oxycodone time to Cmax (tmax) was significantly longer (P<0.001) for intact immediate-release/extended-release oxycodone/acetaminophen than immediate-release oxycodone/acetaminophen. The pharmacokinetics of crushed immediate-release/extended-release and immediate-release oxycodone/acetaminophen (30/1,300 mg) followed a similar pattern. Crushing did not shorten the median oxycodone tmax for immediate-release/extended-release oxycodone/acetaminophen (30/1,300 mg). Strong correlations were observed between oxycodone Cmax and area under the curve from time 0 to time x peak effects and area under the subjective effect curve from time 0 to time x for all subjective effects (R2=0.711-0.997). Immediate-release/extended-release oxycodone/acetaminophen produced lower oxycodone Cmax and longer tmax than immediate-release oxycodone/acetaminophen. Lower oxycodone concentrations, particularly at earlier time points, were strongly correlated with lesser positive subjective drug effects.

Human abuse potential of immediate-release/extended-release versus immediate-release hydrocodone bitartrate/acetaminophen: a randomized controlled trial in recreational users of prescription opioids

Background. The abuse potential of prescription opioids is well established. This study compared positive, subjective drug effects of single, equal doses of biphasic immediate release (IR)/extended release (ER) hydrocodone bitartrate (HB)/acetaminophen (acetyl-p-aminophenol [APAP]) 7.5/325 mg tablets versus IR HB/APAP 7.5/325-mg tablets and placebo. Methods: Healthy adult recreational users of prescription opioids entered this randomized, double-blind, double-dummy, active- and placebo-controlled, seven-way crossover study. Participants received single, total doses of IR/ER HB/APAP 22.5/975 mg (intact; three active tablets) and 45/1950 mg (intact and crushed [encapsulated]; six active tablets), IR HB/APAP 22.5/975 mg (intact; three active tablets) and 45/1950 mg (intact and crushed [encapsulated]; six active tablets), and placebo. Peak subjective effects (Emax); time to peak effects (TEmax); and area under the drug–effect curves for drug liking, high, and good drug effects were measured using visual analog scales. Median values with 95% confidence interval (CI) were compared using analysis of variance. Results: Among completers (n = 52), IR/ER HB/APAP produced delayed and lower peak effects compared to equal doses of IR HB/APAP. Comparing intact tablets, the drug liking Emax (median [95% CI]) was significantly lower for IR/ER HB/APAP 45/1950 mg (78.0 [73.0, 81.0]) than an equal dose of IR HB/APAP (89.5 [85.0, 93.0]; difference, –8.5 [–12.0, –6.0]; P < 0.001). Similar results were observed for intact IR/ER HB/APAP and IR HB/APAP 22.5/975 mg. Crushing IR/ER HB/APAP 45/1950 mg delayed these effects compared with an equal dose of crushed IR HB/APAP and intact IR/ER HB/APAP. Conclusion. IR/ER HB/APAP resulted in lower subjective positive drug effects than an equal dose of IR HB/APAP. Crushing IR/ER HB/APAP also delayed the onset of subjective effects compared with intact IR/ER HB/APAP. These findings suggest that biphasic IR/ER HB/APAP has lower abuse potential than IR HB/APAP in single equal doses. Registration: This Phase I clinical trial conducted in the USA was not registered.

Comparison of Subjective Effects of Extended-Release Versus Immediate-Release Oxycodone/Acetaminophen Tablets in Healthy Nondependent Recreational Users of Prescription Opioids: A Randomized Trial

Background: Prescription opioids have substantial abuse potential. This study compared the positive subjective drug effects of a newly developed extended-release (ER) oxycodone (OC)/acetaminophen (acetyl-para-aminophenol [APAP]) formulation with those of immediate-release (IR) OC/APAP. Methods: This randomized, double-blind, active- and placebo-controlled, 7-way crossover study enrolled healthy volunteers who were recreational prescription opioid users. The protocol was approved by an institutional review board and all participants provided written informed consent. Participants received single doses of intact ER and IR OC/APAP 15/650 mg, intact ER and IR OC/APAP 30/1300 mg, crushed ER and IR OC/APAP 30/1300 mg, and placebo. Peak subjective effects (Emax), time to Emax, and area under the drug-effect curves for drug liking, drug high, and good drug effects were measured using visual analogue scales. Least squares means with 95% confidence interval were compared using analysis of variance. Results: Among completers (N = 55), intact ER OC/APAP produced delayed and lower peak effects versus IR OC/APAP. Comparing intact tablets, the drug liking Emax (least squares means [95% confidence interval]) was significantly lower for OC/APAP 30/1300 mg (76.4 [72.8 to 80.0]) than for IR OC/APAP 30/1300 mg (85.6 [81.9 to 89.2]; difference, −9.2 [−13.1 to −5.2]; P < 0.001). Similar results were observed for intact ER and IR OC/APAP (15 mg/650 mg). Crushing ER OC/APAP 30/1300 mg further delayed these effects compared with the same dose of crushed IR OC/APAP and intact ER OC/APAP. Conclusions: Extended-release OC/APAP produced lower subjective drug effects than IR OC/APAP. Crushing ER OC/APAP further delayed onset of subjective effects compared with intact ER OC/APAP. The ER OC/APAP may be less attractive for abuse than IR OC/APAP. Clinical trial registration: This phase 1 study conducted in the United States was not registered.