Psychedelics: Science sabotaged by Social Media

The substantial challenges facing high and low dose psychedelic drug development to achieve regulatory approval have been documented in the scientific literature. These limitations have not deterred drug developers and social media from repeatedly misleading patients, the public and health professionals. Developing "micro doses" of psychedelics overcomes many of the scientific and regulatory challenges of high dose psychedelics. If micro-dosing could be shown to be efficacious and safe for long term use, it could be administered in the typical model for treatment of mental disorders. Such a model would be more cost effective than the high dose/intense psychotherapy model currently described and could be readily available to all individuals who need another medication option. Outpatient psychotherapeutic agents have a clear route for approval and would be unlikely to be burdened by the extensive Risks Evaluation and Mitigation Strategy needed for high dose use. There may be a different therapeutic role for both high and low dose psychedelic agents. This article is part of the Special Issue on "National Institutes of Health Psilocybin Research Speaker Series".

Studies with psychedelic drugs in human volunteers

Scientific curiosity and fascination have played a key role in human research with psychedelics along with the hope that perceptual alterations and heightened insight could benefit well-being and play a role in the treatment of various neuropsychiatric disorders. These motivations need to be tempered by a realistic assessment of the hurdles to be cleared for therapeutic use. Development of a psychedelic drug for treatment of a serious psychiatric disorder presents substantial although not insurmountable challenges. While the varied psychedelic agents described in this chapter share some properties, they have a range of pharmacologic effects that are reflected in the gradation in intensity of hallucinogenic effects from the classical agents to DMT, MDMA, ketamine, dextromethorphan and new drugs with activity in the serotonergic system. The common link seems to be serotonergic effects modulated by NMDA and other neurotransmitter effects. The range of hallucinogens suggest that they are distinct pharmacologic agents and will not be equally safe or effective in therapeutic targets. Newly synthesized specific and selective agents modeled on the legacy agents may be worth considering. Defining therapeutic targets that represent unmet medical need, addressing market and commercial issues, and finding treatment settings to safely test and use such drugs make the human testing of psychedelics not only interesting but also very challenging. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.

Categorization of Abuse Potential-Related Adverse Events

All drugs with central nervous system activity must undergo an assessment of their abuse potential, and these data must be included in a New Drug Application. Part of this assessment is an analysis of treatment-emergent adverse events that occur during clinical development. Using an iterative consensus strategy, we evaluated and grouped an available list of 213 flag terms for abuse potential from the Food and Drug Administration, into categories and assessed the relevance of the terms to primary abuse behavior. Consequences of abuse (28%) were most common, followed by diagnoses (19%), altered thoughts (18%), cognitive effects (10%), stimulation/anxiety (9%), central nervous system depression (9%), and mood elevation (1%). The vast majority of abuse potential-related terms reflects treatment-emergent adverse events, not behaviorally motivating features to abuse a drug. Almost 30% of terms are related to altered perception or altered cognition. These are serious consequences in the context of abusable psychoactive drugs. Only 20% of terms were rated as definitely or probably reflecting intrinsic behavioral reinforcing potential, and 30% were assessed as having weak predictive utility. Sponsors need to have an explicit strategy for collecting, interpreting, and analyzing abuse-related adverse event information completely and accurately.

Update on tamper-resistant drug formulations

An expert panel convened in 2005 by the College on Problems of Drug Dependence (CPDD) to consider strategies to reduce the risk of prescription medication abuse concluded that drug formulation plays a significant role in determining risk of abuse. Efforts on the part of the pharmaceutical industry to develop drugs that deter abuse have focused primarily on opioid formulations resistant to common forms of tampering, most notably crushing or dissolving the tablet to accelerate release. Several opioid formulations developed to be tamper resistant have been approved, but the US Food and Drug Administration has not approved explicit label claims of abuse deterrence and has stated that any such claim will require substantial postmarketing data. Drug development efforts in this area raise questions about the relative impact of abuse-deterrent formulations, not only on individuals who might abuse a medication, but also on patients who are compliant with therapy. This review discusses progress since the 2005 CPDD meeting with an emphasis on opioids. Articles cited in the review were identified via a PubMed search covering the period between January 1, 2000, and October 5, 2011. Scientific work presented by the authors and their colleagues at meetings held through May 2012 also was included. Published literature suggests that development of abuse-deterrent products will require broad public health support and continued encouragement from regulatory authorities so that such products will become the expected standard of care for certain drug classes.

Oral ketamine as a positive control in human abuse potential studies

The selection of a relevant and appropriate positive control is of key importance in the design of a clinical abuse potential study. Ketamine is a N-methyl-d-aspartate receptor antagonist used clinically as an anaesthetic, yet also abused for its euphoric and perceptual properties. The current study sought to identify 2 doses of oral ketamine that are safe and produce subjective effects that would make them suitable for use as positive controls in abuse potential studies. A single-center, partially double-blind, placebo-controlled, ascending dose (65, 100 and 150 mg) study was carried out in 11 healthy recreational polydrug users who first passed a pharmacologic qualification session to ensure they could distinguish and like the effects of a psychoactive drug (20mg d-amphetamine) compared to placebo. Subjective data were collected through questionnaires (e.g., Addiction Research Center Inventory [ARCI] scales) and visual analog scales (VAS). Generally, oral ketamine was well tolerated and could be used safely at 65 mg and 100mg. Peak responses to ketamine were significantly different (p<0.05) from placebo on measures of positive (e.g., drug liking VAS), perceptual (e.g., VAS of floating, detached, hallucinating) and sedative (e.g., ARCI phenobarbital-chlorpromazine-alcohol group scale) effects. Effects were generally not dose-dependent, though significant differences for some subjective effects measures were observed between 65 mg and 100mg ketamine. The current study indicates that oral ketamine doses of 65 mg and 100mg are useful positive controls for future abuse potential studies of compounds with a similar mechanism of action, or with possible perception-altering and euphoric effects.

A randomized, double-blind, placebo-controlled, crossover study to evaluate the subjective abuse potential and cognitive effects of nabiximols oromucosal spray in subjects with a history of recreational cannabis use

OBJECTIVE

This study aimed to evaluate the abuse potential and cognitive effects of nabiximols (Sativex, GW Pharma Ltd. Salisbury, UK), an oromucosal spray primarily containing delta‐9‐tetrahydrocannabinol (THC) and cannabidiol (CBD).

METHODS

This was a single‐dose, randomized, double‐blind, crossover study comparing nabiximols (4, 8, and 16 consecutive sprays: 10.8, 21.6, and 43.2 mg THC, respectively) with dronabinol 20 and 40 mg (synthetic THC: Marinol, Solvay Pharmaceuticals, Brussels, Belgium) and matching placebos in 23 recreational cannabis users. Subjective and cognitive/psychomotor measures were administered over 24 h post‐dose.

RESULTS

Dronabinol was significantly different from placebo on abuse potential measures, thereby confirming study validity. Nabiximols 10.8 mg was not significantly different from placebo on primary measures but was different on some secondary measures. Nabiximols 21.6 mg was significantly greater than placebo on some primary/secondary measures, whereas nabiximols 43.2 mg showed significant effects on most measures. Nabiximols 10.8 mg was significantly lower than dronabinol doses on most measures ( p < 0.05). Dronabinol 20 mg effects were numerically higher than nabiximols 21.6 mg but were statistically significant only for some measures. Dronabinol 40 mg and nabiximols 43.2 mg were generally not statistically different.

CONCLUSIONS

Both dronabinol and nabiximols had significant abuse potential compared with placebo at higher doses. Nabiximols showed similar or slightly less abuse potential compared with dronabinol. Therefore, the abuse potential of nabiximols should be no higher than that of dronabinol.

Effect of eslicarbazepine acetate and oxcarbazepine on cognition and psychomotor function in healthy volunteers

The results of two single-blind studies conducted to evaluate the cognitive and psychomotor effects of eslicarbazepine acetate and oxcarbazepine following single and repeated administration in healthy volunteers are reported. The cognitive and psychomotor evaluation consisted of several computerized and paper-and-pencil measures. Eslicarbazepine acetate and oxcarbazepine had similar overall cognitive profiles and did not cause clinically relevant cognitive impairment. The incidence of adverse events was lower with eslicarbazepine acetate than with oxcarbazepine.

Pharmacotherapy of alcohol and drug problems

Substantial progress has been made in the pharmacotherapy of withdrawal syndromes and organic complications of alcohol and drug abuse. Diazepam loading (alcohol withdrawal), phenobarbital loading (barbituate withdrawal) and diazepam tapering (benzodiazepine discontinuation) have considerably simplified treatment of withdrawal syndromes and have enhanced efficacy. Propylthiouracil shows considerable promise in the out-patient treatment of alcoholic liver disease. New medications, particularly those modifying serotonergic function, have efficacy in decreasing alcohol consumption and show considerable therapeutic potential. Human pharmacology and pharmacotherapy should be a central part of training programmes in the field in order that further advances can be made.

Relative abuse potential of opioid formulations in Canada: a structured field study

INTRODUCTION

While prescription opioids can improve quality of life through pain relief they are susceptible to misuse. This field study characterizes the relative susceptibility and attractiveness of a new analgesic patch, with fentanyl embedded in a matrix material, compared to other opioid dose formulations.

METHODS

Recreational opioid abusers (N = 42; 31 male, 1 female)from three Canadian sites participated in structured interviews. They were presented with nine products, some of which were hypothetical (fentanyl [F], hydromorphone [H], and oxycodone [O] in each of three formulations: matrix patch [M], reservoir-type gel patch [G], and tablet [T]). The attractiveness and tampering potential of each product was ranked using two 7-point Likert scales (Value of Product and Likelihood to Tamper), an index representing the product of the two scales, a 17-item Opiate Attractiveness Scale (OAS), relative street value, and rank order of overall desirability. Non-parametric analyses were used to compare each product to the FM.

RESULTS

The FT, HT, and FM were highly valued and most likely to be tampered with. The products were ranked in decreasing order of desirability as follows: FT > HT > FM > FG > OT > HM > HG > OM > OG. On the OAS, FM was more attractive than all gel-patch products (p < 0.001), and OT was most attractive overall. FM was statistically similar to OT, FT, OM, and HT. Of the 42 subjects, 25 (60 percent) preferred the matrix patch to the gel patch. Of the 17 subjects who preferred the gel patch, 10 (59 percent) were from a region generally unfamiliar with that formulation.

CONCLUSIONS

Fentanyl is attractive to opioid abusers regardless of formulation. In Canada, a fentanyl matrix patch may be at higher risk for diversion, tampering, and abuse than other transdermal opioid formulations. These findings should be confirmed by epidemiological studies. Comparative risk management programs should be part of the development of any new narcotic delivery system.

3alpha-reduced neuroactive steroids and their precursors during pregnancy and the postpartum period

Allopregnanolone (ALLO) and pregnanolone (PREG), the 3alpha-reduced metabolites of progesterone (PROG), are potent modulators of gamma-aminobutyric acid type A receptors that may function as endogenous anxiolytics. They are purported to be involved in the etiology or expression of clinical depression. In the present study we quantified ALLO and PREG, as well as PROG, 5alpha-dihydroprogesterone (5alpha-DHP), 5beta-dihydroprogesterone (5beta-DHP), epiallopregnanolone and pregnenolone (PREGNEN), in plasma from healthy women at five time points during pregnancy and the postpartum period. Analysis was by gas chromatography/electron capture - negative chemical ionization - mass spectrometry. Neuroactive steroids increased significantly from 10 to 36 weeks of pregnancy, except for 5beta-DHP and PREGNEN which did not change significantly. PROG was the most abundant steroid throughout pregnancy, followed by 5alpha-DHP and ALLO. Metabolite to precursor ratios differed depending on the enzyme and substrate: the turnover of PROG to 5alpha-DHP (catalyzed by 5alpha-reductase) was stable while the conversion of PROG to 5beta-DHP (catalyzed by 5beta-reductase) decreased later in pregnancy. 3alpha-Hydroxysteroid oxidoreductase-mediated turnover of 5alpha- and 5beta-DHP to their metabolites ALLO and PREG, respectively, rose during pregnancy, but the turnover of 5alpha-DHP to ALLO dropped at the late prenatal visit. At 6 weeks postpartum all steroids were significantly reduced compared with late prenatal values, with 5alpha-DHP being the most abundant postpartum steroid. These results provide the basis for further study of neuroactive steroids in psychiatric conditions of pregnancy and the postpartum period.

EMD 281014, a specific and potent 5HT2 antagonist in humans: a dose-finding PET study

While serotonin 5HT2-receptors have been implicated in the etiology and pharmacological treatment of a number of neuropsychiatric conditions, there are few potent and specific agents available for use in human clinical studies. EMD 281014 is a highly specific 5HT2-receptor antagonist that is currently under development. To find optimal doses for early clinical studies, we conducted a PET study using [18F]setoperone in nine healthy subjects scanned at baseline and following the administration of 1, 3, and 7 mg EMD 281014. The study drug was well tolerated by all study participants, and all doses resulted in > or =70% occupancy at frontal 5HT2-receptors 3 h after drug administration. The data suggest that daily dosing of > or =3 mg EMD 281014 should be sufficient to provide sustained high levels of 5HT2-receptor occupancy in future clinical trials.

Mood changes during pregnancy and the postpartum period: development of a biopsychosocial model

OBJECTIVE

Women are vulnerable to mood changes during pregnancy and the postpartum period. We set out to empirically test the hypothesis that biological and psychosocial variables interact to result in this vulnerability.

METHOD

Using structural equation modeling techniques, we developed an integrative model of perinatal mood changes from clinical, psychosocial, hormone and mood data collected from 150 women in late pregnancy and at 6-weeks postpartum.

RESULTS

In the prenatal model, biological variables had no direct effect on depressive symptoms. However, they did act indirectly through their significant effects on psychosocial stressors and symptoms of anxiety. The same model did not fit the postpartum data, suggesting that different causal variables may be implicated in postpartum mood.

CONCLUSION

This model demonstrates the importance of considering both biological and psychosocial variables in complex health conditions such as perinatal mood disorders.

Measurement issues in postpartum depression part 1: anxiety as a feature of postpartum depression

We investigated the contribution of anxiety symptoms to scores on the Edinburgh Postnatal Depression Scale (EPDS) between 36 weeks gestation and 16 weeks postpartum in 150 women. The 3-item anxiety subscale of the EPDS accounted for 47% of the total score in late pregnancy, and 38% of the total score in the postpartum period. Two categories of anxiety were common in the perinatal period: subsyndromal, situational anxiety (in particular during the last weeks of pregnancy); and clinically significant comorbid anxiety, which was experienced by nearly 50% of clinically depressed pregnant and postpartum women. The close relationship between anxiety and depression raises questions about whether symptoms of anxiety might be more common in the perinatal period than in other depressions. A strong role for anxiety symptoms in postpartum depression, and implications for its etiology and treatment, are discussed.

Measurement issues in postpartum depression part 2: assessment of somatic symptoms using the Hamilton Rating Scale for Depression

Assessment of the somatic symptoms of depression in perinatal women has been debated due to potential overlap with normal physical complaints of pregnancy and childbirth. We investigated the properties of the 17-item Hamilton Rating Scale for Depression (HAMD), which includes somatic items, between 36 weeks gestation and 16 weeks postpartum in 150 women. Scores on the HAMD were highly correlated with scores on measures that avoid somatic items. Scores on somatic items were not well correlated with the total HAMD score in pregnancy, but the correlations increased at 6 weeks postpartum. In contrast, scores on HAMD item 1 ("Depression") were less well correlated with the total score at 6 weeks postpartum than prenatally, suggesting that postpartum women may be less likely to articulate their difficulties as "depression", and more likely to describe somatic complaints such as low energy or insomnia. Implications for the assessment of depression in this population are discussed.

Naltrexone in the treatment of alcohol dependence: a Canadian trial

OBJECTIVES

Alcohol dependence is a prevalent psychiatric disorder affecting approximately 12% of the adult population at some point in their lifetime. Psychosocial treatments are associated with only modest success rates. The first Canadian clinical trial with naltrexone, an opiate antagonist, was conducted to evaluate its safety and usefulness as an adjunctive treatment in the management of alcohol dependence.

METHODS

One hundred twenty alcohol-dependent individuals were assessed to receive treatment with 50 mg of naltrexone orally for 12 weeks in an open-label trial. Patients were seen biweekly and received a concurrent psychosocial intervention. Treatment was conducted at multiple sites in Canada.

RESULTS

Fifty-four per cent of subjects completed the entire 12 weeks of treatment. During the study, 39% of patients abstained, while of the individuals reporting drinking at baseline, 86% were consuming less alcohol by their final visit. These reductions were accompanied by a significant decrease in craving for alcohol at week 12, as measured by the Obsessive Compulsive Drinking Scale (P<0.01). Naltrexone was well tolerated and no serious adverse events were experienced.

CONCLUSIONS

The data lend support to the hypothesis that endogenous opioid activity is involved in the regulation of alcohol intake, and that antagonists of endogenous opioids decrease craving and drinking. Opiate antagonists such as naltrexone are a new strategy in the treatment of alcohol dependence. Naltrexone can be safely given to female and male alcoholics, is acceptable to patients, and plays a role in reducing alcohol consumption and preventing relapse to heavy drinking.

Treatment of codeine dependence with inhibitors of cytochrome P450 2D6

Codeine is O-demethylated by cytochrome P450 2D6 (CYP2D6) to form the more potent drug morphine, accounting for much of codeine's analgesic and dependence-producing properties. Because morphine production can be decreased by inhibition of CYP2D6, the authors hypothesized that CYP2D6 inhibition could be used to treat codeine dependence. A randomized, double-blind, placebo-controlled trial was conducted. All patients received brief behavioral therapy. Two weeks of baseline monitoring were followed by 8 weeks of daily treatment with fluoxetine or quinidine (two potent CYP2D6 inhibitors) or placebo. Thirty patients were assessed (all white, age 40 + 12 years using 127 + 79 mg/day of codeine [mean + SD]), and 17 entered treatment. Eight patients remained in the study by treatment week 8. Quinidine > fluoxetine > placebo inhibited CYP2D6 as reflected in the change of the O-demethylation of dextromethorphan, a specific CYP2D6 probe. At treatment week 8, placebo, quinidine, and fluoxetine reduced mean daily codeine intake by 57%, 56%, and 51% of baseline intake respectively; there was no difference among treatment groups. In this small sample, CYP2D6 inhibitors did not appear to have a useful role in the treatment of codeine dependence.

Efficacy of dexfenfluramine in the treatment of alcohol dependence

BACKGROUND

A substantial body of evidence supports a role for serotonin in modulating alcohol intake, which suggests that this neurotransmitter represents a promising target for pharmacotherapy development for alcohol use disorders. Dexfenfluramine. a serotonin releaser and reuptake inhibitor, decreases alcohol self-administration by rats. Its greater potency and several mechanisms of action suggest it should be more effective in treating alcohol dependence than drugs that only inhibit serotonin reuptake.

METHODS

We conducted an 11 week, randomized, double-blind trial that compared oral placebo and dexfenfluramine 7.5, 15, 22.5, and 30 mg bid in 136 alcohol-dependent patients. A brief behavioral intervention was offered concurrently.

RESULTS

The majority of subjects were male (72%), and the age of the group was 44 +/- 1 years (mean +/- SD). Both placebo- and drug-treated groups significantly reduced alcohol consumption compared with baseline (a 55% decrease in mean drinks per day; p < 0.01), but there were no significant differences between drug and placebo groups or dose effects for most outcome measures.

CONCLUSIONS

Our results with dexfenfluramine are further evidence that serotonergic medications on their own do not significantly reduce alcohol consumption in alcohol-dependent individuals. Combination pharmacotherapy with agents that act on different receptors or neurotransmitter systems (e.g., naltrexone plus dexfenfluramine) may be one way to enhance serotonergic effects on drinking behavior and should be considered in future medication development clinical trials.

Inhibition of cytochrome P450 2D6 modifies codeine abuse liability

Oral codeine preparations, widely used for analgesia and cough suppression, are abused by some individuals for their mood-altering properties. The enzymatic O-demethylation of codeine is catalyzed by cytochrome P450 2D6 (CYP2D6), leading to the production of metabolites (morphine, morphine-6-glucuronide) that are pharmacologically more potent than codeine. A placebo-controlled, single-blind study was conducted to characterize the subjective effects of codeine associated with abuse liability and to determine the importance of metabolic O-demethylation to codeine abuse liability. Twelve non-drug-dependent subjects received oral administration of placebo and codeine 60, 120, and 180 mg, and a favorite dose (FD) was determined for each subject. The FD was readministered after pretreatment with placebo, 50 mg of quinidine (a specific, selective CYP2D6 inhibitor) once, or 50 mg of quinidine given four times a day for 4 days. Single-dose quinidine pretreatment significantly decreased the recovery of O-demethylated metabolites in plasma (p < 0.01) and resulted in a decrease in the positive (e.g., "high," p < 0.05) and negative (e.g., nausea, p < 0.05) subjective effects of codeine in both the FD120 and FD180 groups. Short-term quinidine pretreatment inhibited codeine O-demethylation more than did single-dose quinidine pretreatment (p < 0.01), and it decreased positive codeine effects in the FD120 group (N = 7), but unexpectedly not in the FD180 group (N = 5). These results suggest that the O-demethylated metabolites contribute substantially to the subjective effects and abuse liability of codeine.

Cytochrome P450 2D6 and treatment of codeine dependence

Oral opioid analgesics such as codeine are used extensively worldwide and are frequently misused. Codeine is a substrate of CYP2D6, a genetically polymorphic P450 enzyme, and is metabolized to the more potent drug morphine. CYP2D6 activity can be inhibited by fluoxetine, and the inhibition of morphine formation may help individuals reduce their use of codeine. Fourteen long-term users of oral opiates (principally codeine) were assessed for an open-label pilot treatment study of fluoxetine 20 mg/day combined with a brief behavioral intervention and structured tapering of the opiate. Eight subjects entered and completed the 8-week treatment. Opiate use decreased by 30% to 100% of baseline use (p < 0.0001) in parallel with a decrease in CYP2D6 activity. Fluoxetine may have a role in the treatment of opiate dependence by decreasing opiate-reinforcing properties.

Attenuation of the euphoric effects of cocaine by the dopamine D1/D5 antagonist ecopipam (SCH 39166)

BACKGROUND

The subjective and reinforcing effects of cocaine in humans are associated with the enhancement of endogenous dopamine function in the mesolimbic system. This study examined the role of dopamine D1-like receptors in the behavioral and mood effects of cocaine by evaluating the effects of the selective D1/D5 antagonist ecopipam (SCH 39166) on subjective responses to intravenous cocaine in 11 subjects with cocaine dependence as defined by DSM-IV.

METHODS

Subjects were pretreated in a randomized double-blind fashion with either placebo or 10 mg, 25 mg, or 100 mg of ecopipam orally on 4 separate occasions. Two hours later a single intravenous injection of 30 mg of cocaine was administered. Subjective and cardiovascular responses were measured and blood samples for pharmacokinetic evaluation were obtained prior to cocaine dosing and at various times after dosing.

RESULTS

The euphoric (P = .004) and stimulating (P = .03) effects of cocaine were attenuated in a dose-dependent manner by ecopipam, while ratings of desire to take cocaine were diminished (P = .02). Ecopipam in combination with cocaine was safe and well tolerated.

CONCLUSION

These data indicate a potentially important role for D1-like receptors in the acute mood-altering and rewarding effects of cocaine in humans.

Risk of drug dependence and abuse posed by barbiturate-containing analgesics

Concern has been raised that the barbiturate component of barbiturate-containing analgesics constitutes a public and individual health problem because of information from literature before 1966 concerning preclinical and clinical abuse liability, and the dependence risk of barbiturates. The safety of barbiturates alone and in combination in analgesics was reviewed. In addition, information from manufacturers of combination products were evaluated. A meta-analysis was not possible because of the paucity of formal clinical trials. Even though barbiturates have a narrow margin of safety and substantial abuse potential, there is no evidence that barbiturate-containing analgesics without codeine represent a public health or social problem because of their abuse potential. However, proper studies to confirm this theory have not been performed. In the absence of better data concerning efficacy and lack of dependence potential, barbiturate-containing analgesics are not first-line medications for the initiation of treatment for pain. Codeine-containing combination analgesics have the potential to be a more important public health problem than those with only barbiturate in the combination.

Characteristics of dependent and nondependent regular users of codeine

Although codeine is a widely used medication, the problems of codeine abuse and dependence have not been well-studied. This study characterized regular codeine users (using at least 3 days per week for 6 months, excluding those using codeine for the treatment of cancer pain) through a self-completed questionnaire. Recruitment through newspaper advertisements resulted in a total of 339 eligible questionnaires. Thirty-seven percent of subjects met DSM-IV criteria for codeine dependence. Dependent subjects (mean age, 40 +/- 10 years) were using an average of 179 (+/-171) mg of codeine per day. Codeine was predominantly used in the form of combination products with acetaminophen. Dependent subjects identified specific problems causally related to their codeine use such as depression (23%), anxiety (21%), and gastrointestinal disturbances (13%). The dependent subjects reported problems with other drugs more than did nondependent users (alcohol, 57% vs. 26%; cannabis, 23% vs. 5%; sedative/hypnotics, 33% vs. 12%; and heroin, 11% vs. 2%, respectively). Most were taking codeine primarily for a chronic pain problem (81%), although the dependent subjects currently found codeine less effective for treating pain than did the nondependent subjects and were more likely to use codeine for pleasurable effects, to relax, or to prevent withdrawal symptoms. This study showed that dependence is associated with the regular use of codeine. Pain is a key issue with these users; however, they are probably not receiving optimal treatment. There is a need to identify individuals experiencing problems with their codeine use and to develop optimal prevention and treatment strategies.

Long-term codeine use is associated with depressive symptoms

A community survey was conducted among long-term (>6 months) users of codeine-containing products to characterize chronic use of these extensively consumed medications. Respondents recruited through newspaper advertisements completed a mailed questionnaire. Three hundred thirty-nine completed questionnaires were obtained, yielding a response rate of 70%. Codeine dependence/abuse as defined by DSM-IV criteria was present in 41% of the respondents. Two thirds of the subjects had sought help for mental health problems, most often depression (70%). Scores on the Symptom Checklist-90 subscales were modestly elevated, particularly on the Depression subscale (1.2 +/- 0.9). Long-term codeine use is strongly associated with dependence. Depression and depressive symptoms are common. These data suggest that dysphoric mood states may be significant in maintaining long-term codeine use.

A controlled trial of ondansetron, a 5-HT3 antagonist, in benzodiazepine discontinuation

Serotonin is implicated in the etiology of anxiety disorders and in the anxiolytic actions of benzodiazepines. Preclinical studies with 5-HT3 receptor antagonists, including ondansetron, show they have anxiolytic properties and that ondansetron suppresses withdrawal anxiety after abrupt discontinuation of chronic benzodiazepine treatment. We evaluated the efficacy of ondansetron as an adjunctive medication in the discontinuation of benzodiazepines in long-term users. One hundred eight patients who had used alprazolam or lorazepam regularly for > 3 months entered, and 97 completed a randomized double-blind discontinuation treatment program during which they received either ondansetron 2 mg twice daily or placebo and flexibly tapered their benzodiazepine over a 6-week period. There were no significant differences between the patients who had entered and completed treatment. Three weeks postmedication, 63% of the patients discontinued use of benzodiazepine. The percentage of reduction of benzodiazepine daily dosage at all time points in the treatment trial was similar for the ondansetron and placebo groups. Ondansetron had no significant effects on severity of withdrawal symptoms or levels of anxiety. High placebo response may have prevented detection of an ondansetron effect. At 1 year follow-up, 68% of patients reported that they stopped using benzodiazepine. Patient characteristics were more important than ondansetron in tapered benzodiazepine discontinuation.

CYP2D6 inhibition in patients treated with sertraline

Sertraline, a selective serotonin reuptake inhibitor used to treat depression, inhibits CYP2D6 in vitro (Ki = 1.2 microM) less potently than fluoxetine (Ki = 0.15 microM). To determine the extent and time course of CYP2D6 inhibition in patients, six males (mean age: 40 years, range: 29-64 years), who were starting treatment for depression with sertraline, were phenotyped on five occasions (once before treatment and approximately 3, 7, 14, and 21 days later). Phenotype status was determined using oral dextromethorphan (30 mg) by calculating the urinary ratio of O-demethylated metabolites to parent drug (i.e., log ODMR). CYP2D6 genotype was determined by leukocyte DNA analysis using polymerase chain reaction amplification. Compliance was confirmed by sertraline plasma levels. Daily sertraline dosages ranged from 50 to 150 mg. Genotype results indicated all subjects were extensive metabolizers (four homozygous wild type [wt], two heterozygous wt/B mutation). Phenotype results showed that CYP2D6 inhibition in patients treated with sertraline appeared to be related to baseline CYP2D6 activity and sertraline dosage. Some patients with high CYP2D6 activity can demonstrate inhibition with sertraline dosages as low as 50 mg.

Multiple drug use and psychiatric comorbidity in patients admitted to the hospital with severe benzodiazepine dependence

This study aimed to evaluate the concurrent and lifetime psychiatric comorbidity and drug use patterns in patients admitted to the hospital for detoxification from benzodiazepines. Psychiatric assessments using the Structured Clinical Interview for DSM-III-R with a psychosis screening module (SCID-P and II) were conducted in 30 inpatients admitted to the medical unit treatment unit of the Clinical Research and Treatment Institute of the Addiction Research Foundation for the treatment of severe benzodiazepine dependence. Patients (mean age, 36 years; range, 22-58; number of DSM-III-R criteria met for benzodiazepine substance dependence, > or = 7 out of 9 [73%], all 9 criteria [40%]) used benzodiazepines and other drugs over prolonged periods of time at high doses, and their daily functioning was substantially impaired (Mean Global Assessment of Functioning Score, 48; range, 31-60). The most common lifetime psychiatric diagnoses were major depression (33%), other psychoactive drug dependence (100%) (opioids, 77%; alcohol, 53%), and panic disorder (30%). Current psychiatric diagnoses in addition to benzodiazepine dependence included other psychoactive substance use disorders (83%) (opioids, 67%; cocaine, 13%; multiple concurrent substance use, 17%), panic disorder (13%), and generalized anxiety disorder, (20%). Personality disorders included antisocial (42%), avoidant (25%), and borderline (17%). These findings demonstrate that in patients severely dependent on benzodiazepines, additional psychoactive substance use and mental disorders are prominent. The pattern of drug use and psychiatric comorbidity differentiates these patients from therapeutic-dose benzodiazepine users.

Clinical efficacy of the 5-HT3 antagonist ondansetron in alcohol abuse and dependence

Medications that act on the serotonergic system have been found to be of benefit in the treatment of alcohol-dependent individuals. In a randomized, placebo-controlled study, the efficacy of 6 weeks of ondansetron, a 5-HT3 antagonist (0.25 mg bid or 2.0 mg bid), in the treatment of 71 nonseverely alcohol-dependent males was tested. The results showed reduction of drinking differences were steadily increasing toward the end of the treatment period approached significance at week 7 in the 0.25 mg group (p = 0.06). Twice as many patients in this group showed > or = 2 standard deviations decrease in drinking compared with the other groups. When patients drinking > 10 drinks/drinking day at baseline (n = 11) were excluded from the analysis, significant group differences were found at both treatment and follow-up, with the lower ondansetron dose producing the greatest reduction from baseline (i.e., 2.8 standard drinks; -35% compared with baseline and -21% compared with placebo; p < 0.02-0.001). Within this group, there was an almost 4-fold greater number of patients showing a clinically meaningful decrease in drinking. Lower baseline drinking and higher level of education were significant and strong predictors of drinking reduction during treatment. Ondansetron was very well tolerated; hence, further long-term studies with 5-HT3 antagonists alone or in combination with other treatment components may offer promise for treatment of alcoholism.

Alprazolam and benzodiazepine dependence

The incidence of nonmedical use of alprazolam is very low relative to its widespread legitimate medical use; in fact, given the millions of patients who have received this medication, the incidence is remarkably small. In particular, among patients with anxiety disorders, dependence does not appear to be a clinically important problem. Alprazolam abuse and dependence represent only a small fraction of the large and serious nonmedical use problem in the United States, and when they occur, are among individuals who abuse other drugs. For example, a serious problem of alprazolam abuse may exist among patients in methadone maintenance treatment. A similar problem exists with diazepam. Alcohol abusers and alcohol-dependent individuals are another group among whom concern about benzodiazepine and alprazolam abuse exists. However, more and better information about the extent and nature of this use is needed. Many patients with alcohol or drug abuse also have anxiety disorders for whom effective pharmacotherapy may be needed. In the interim, caution but not prohibition to use should prevail in prescribing alprazolam to such patients. To the extent that nonmedical alprazolam use exists, evidence suggests that the vast majority of such use is the consequence of the inappropriate prescribing of the medication by a small number of physicians. One way to reduce the inappropriate use of benzodiazepines in methadone programs is to drug test the methadone-maintenance patients and to link positive urine tests to contingency-management strategies. The available data provide some support to the idea that alprazolam and diazepam have more abuse liability than other benzodiazepines.

Characteristics of long-term alprazolam users in the community

The widespread use of benzodiazepines remains a source of concern to the medical profession and the general public, especially as newer compounds come on the market. Our goal was to characterize long-term alprazolam users in the community and to determine whether such use represented abuse or behavioural dependence. We conducted three community surveys to learn about the natural history of long-term alprazolam use. Current long-term alprazolam users (those using the drug for 3 months or longer) were recruited on three separate occasions 1 year apart by identical newspaper advertisements in the metropolitan Toronto area. All respondents were mailed a questionnaire with a stamped, addressed return envelope. Our data from 312 respondents show that: (1) the majority of patients have a substantial history of prior medication use for symptom control (65%), (2) dose escalation is not a characteristic of long-term use, (3) patients change their initial pattern of regular use to one of symptom control only when required, (4) most physicians do not discuss discontinuation of the drug with their patients, (5) patients frequently try to stop their drug use (with a median of 2 attempts) and often report symptoms upon discontinuation, and (6) patients perceive a need for medication use and indicate that alprazolam is effective (75%). We conclude that some patients persistently use alprazolam but that this use does not represent abuse or behavioral dependence.

Comparative drug effects and abuse liability of lorazepam, buspirone, and secobarbital in nondependent subjects

The pharmacologic effects of lorazepam (2 mg), buspirone (20 mg, 10 mg), secobarbital (100 mg), and placebo were compared in 15 male, experienced, intermittent nontherapeutic drug users. All drugs produced a "drug effect," however, buspirone 20 mg was significantly less liked than were lorazepam, secobarbital, or buspirone 10 mg (p less than .05) but not placebo. Lorazepam was liked better than were other drugs only at 1 hour and only compared with buspirone 20 and placebo. Compared with other drugs, lorazepam drug effects were greater and resulted in more prolonged impairment of a motor tracking task, standing steadiness, and memory. Buspirone 20 mg significantly impaired memory at 1 hour compared with placebo. Subjects were more likely to identify buspirone as unfamiliar. Because buspirone 20 mg was less liked than were other drugs, dose escalation as part of drug abuse is not likely to occur. Lorazepam also was not particularly liked and was not different from placebo on most subjective abuse-relevant measures.

Opportunities for treatment of psychoactive substance use disorders with serotonergic medications

The authors review both the preclinical and the clinical evidence for a role of serotonin (5-HT) systems in the regulation of drug-taking behavior. Animal studies show that pharmacologic treatments that enhance 5-HT function, notably selective reuptake inhibitors, reduce the self-administration of a variety of substances of abuse, including ethanol and cocaine. These treatments also tend to suppress consummatory behavior in general. In contrast to the broad spectrum of suppression following 5-HT enhancement, selective antagonists at the 5-HT3 receptor subtype have been reported to reduce ethanol but not cocaine or food intake. Although essentially limited to alcohol abusers, clinical studies seem to support the preclinical findings that a number of 5-HT reuptake inhibitors decrease interest in and intake of alcohol in mild-moderate ethanol-dependent individuals. Furthermore, other serotonergic drugs may show utility in the treatment of alcohol abuse. Another way in which serotonergic medications can be used in treating substance abuse is by the treatment of comorbid psychoactive illness for which such drugs are already known to be effective, e.g., depression and anxiety disorders.

Management of the alcohol withdrawal syndrome

People who suffer acute alcohol withdrawal should be admitted to a hospital if they have a concurrent medical or surgical complication or severe symptoms. Careful assessment, supportive care, and pharmacotherapy, especially loading with a long half-life benzodiazepine such as diazepam, are the essential components of treatment. Patients with milder withdrawal can be managed effectively and safely on an out-patient basis or with nonmedical treatment. The need for pharmacotherapy should be determined on an individual basis. The management of alcohol withdrawal includes offering and initiating long-term treatment to reduce alcohol consumption.

Methadone binding to orosomucoid (alpha 1-acid glycoprotein): determinant of free fraction in plasma

The distribution of basic drugs in blood differs qualitatively from that of acidic drugs. The binding of racemic, d-methadone, and l-methadone to human plasma and isolated protein fractions was studied by equilibrium dialysis at 37 degrees. In plasma samples from 29 healthy subjects free fraction of dl-methadone was (mean% +/- SD) 10.62 +/- 1.43. There were significant variations among subjects (p less than 0.001). The free fraction of the d-isomer was 9.24 +/- 1.61% and of the l-isomer, 12.44 +/- 1.53%. Plasma albumin concentration and degree of binding do not correlate, but in normal hypoalbuminemic subjects the free fraction of dl-methadone correlates negatively with the concentration of alpha 1-acid glycoprotein (alpha 1-AGP), an acute-phase reactant protein. Percentage dl-methadone bound to purified human serum albumin (HSA) (4.1 mg/dl) was 36.60% (mean +/- SD). Isolated alpha 1-AGP bound dl-methadone more avidly. As the alpha 1-AGP increased from 0.05 to 2.0 gm/l, free fraction fell from 92.40% to 8.80%. Addition of alpha 1-AGP (0.05 to 2.0 gm/l) to a physiologic concentration of purified HSA or to whole plasma progressively increased methadone binding. In eight monozygotic twin pairs, within-pair differences in binding of dl-methadone were less than in eight dizygotic twin pairs. Less than 20% of naloxone, codeine, morphine, heroin, pentazocine, and diphenoxylate bound to alpha 1-AGP. Elevations of alpha 1-AGP that occur in a variety of diseases may alter the kinetic and pharmacologic activity of methadone.

Inter- and intrasubject variation in diazepam free fraction

The extent of intersubject variation in diazepam free fraction was measured in fasting plasma of 74 unrelated subjects. Free fraction differences between subjects were significant and ranged from 0.97% to 1.99%. Diazepam free fraction in 29 males was normally distributed about a mean of 1.25% (range, 1.05% to 1.47%), but the distribution in females was skewed to higher free fractions and 40% had values above the highest in males. Albumin concentration (r = -0.27, p less than 0.002) and age (r = 0.44, p less than 0.001) only accounted for a small part of the variation. Within-pair variances were not greater in 11 dizygotic than in 18 monozygotic twin pairs, indicating a greater contribution of environmental than of genetic factors to diazepam binding. The prehemodialysis free fractions of diazepam in 9 uremic patients ranged from 3.44% to 6.69%, and decreased (p less than 0.005) in 7 after 6 hr of hemodialysis. In 10 subjects determination of intrasubject variation in diazepam free fraction between 14-hr fasting and 2-hr postprandial plasma samples indicated that because subjects differ in their pattern of change in free fraction (p less than 0.001), the overall decrease in mean free fraction did not achieve statistical significance (p = 0.10). The mean relative percent change in free fraction within subjects after feeding was 15.2%.