Psychedelic Drugs as Therapeutics: No Illusions About the Challenges.

Interest in the potential therapeutic benefits of psychedelic agents has recently increased. In addition to psilocybin, a wide variety of agents with psychedelic properties have been proposed and partially tested. However, the challenges of obtaining approval to market a restricted psychotomimetic agent are formidable.

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'.

Abuse liability measures for use in analgesic clinical trials in patients with pain: IMMPACT recommendations.

Assessing and mitigating the abuse liability (AL) of analgesics is an urgent clinical and societal problem. Analgesics have traditionally been assessed in randomized clinical trials (RCTs) designed to demonstrate analgesic efficacy relative to placebo or an active comparator. In these trials, rigorous, prospectively designed assessment for AL is generally not performed. The Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) convened a consensus meeting to review the available evidence and discuss methods for improving the assessment of the AL of analgesics in clinical trials in patients with pain. Recommendations for improved assessment include: (1) performing trials that include individuals with diverse risks of abuse; (2) improving the assessment of AL in clinical trials (eg, training study personnel in the principles of abuse and addiction behaviors, designing the trial to assess AL outcomes as primary or secondary outcome measures depending on the trial objectives); (3) performing standardized assessment of outcomes, including targeted observations by study personnel and using structured adverse events query forms that ask all subjects specifically for certain symptoms (such as euphoria and craving); and (4) collecting detailed information about events of potential concern (eg, unexpected urine drug testing results, loss of study medication, and dropping out of the trial). The authors also propose a research agenda for improving the assessment of AL in future trials.

Core outcome measures for opioid abuse liability laboratory assessment studies in humans: IMMPACT recommendations.

A critical component in development of opioid analgesics is assessment of their abuse liability (AL). Standardization of approaches and measures used in assessing AL have the potential to facilitate comparisons across studies, research laboratories, and drugs. The goal of this report is to provide consensus recommendations regarding core outcome measures for assessing the abuse potential of opioid medications in humans in a controlled laboratory setting. Although many of the recommended measures are appropriate for assessing the AL of medications from other drug classes, the focus here is on opioid medications because they present unique risks from both physiological (e.g., respiratory depression, physical dependence) and public health (e.g., individuals in pain) perspectives. A brief historical perspective on AL testing is provided, and those measures that can be considered primary and secondary outcomes and possible additional outcomes in AL assessment are then discussed. These outcome measures include the following: subjective effects (some of which comprise the primary outcome measures, including drug liking; physiological responses; drug self-administration behavior; and cognitive and psychomotor performance. Before presenting recommendations for standardized approaches and measures to be used in AL assessments, the appropriateness of using these measures in clinical trials with patients in pain is discussed.

Research design considerations for clinical studies of abuse-deterrent opioid analgesics: IMMPACT recommendations.

Opioids are essential to the management of pain in many patients, but they also are associated with potential risks for abuse, overdose, and diversion. A number of efforts have been devoted to the development of abuse-deterrent formulations of opioids to reduce these risks. This article summarizes a consensus meeting that was organized to propose recommendations for the types of clinical studies that can be used to assess the abuse deterrence of different opioid formulations. Because of the many types of individuals who may be exposed to opioids, an opioid formulation will need to be studied in several populations using various study designs to determine its abuse-deterrent capabilities. It is recommended that the research conducted to evaluate abuse deterrence should include studies assessing: (1) abuse liability, (2) the likelihood that opioid abusers will find methods to circumvent the deterrent properties of the formulation, (3) measures of misuse and abuse in randomized clinical trials involving pain patients with both low risk and high risk of abuse, and (4) postmarketing epidemiological studies.

Risk management of drug products and the U.S. Food and Drug Administration: evolution and context.

This paper summarizes the background and origins of pharmaceutical risk management and minimization principles and approaches as reflected in FDA statute, policy, and practice. It describes the history of early "risk management" programs, such as the patient package inserts (PPIs) introduced for oral contraceptives in 1976 and medication guides developed for products with safety concerns over the past decade. Exemplary products and programs that include restricted distribution systems such as the early clozapine "blood for drug" program are discussed. The principles and tools described in the US Food and Drug Administration (FDA) risk management guidances of 2005 are likely to be relied upon as the REMS (Risk Evaluation and Mitigation Strategies) mandated by the FDA Amendments Act (FDAAA) of 2007 are implemented.

Cocaine Rapid Efficacy Screening Trial (CREST): a paradigm for the controlled evaluation of candidate medications for cocaine dependence.

AIM: Development of effective medications for the treatment of cocaine dependence remains a major priority for the National Institute on Drug Abuse (NIDA) at the National Institutes of Health. The Cocaine Rapid Efficacy Screening Trial (CREST) paradigm was developed by the Division of Treatment Research and Development (DT R&D) at NIDA with the goal of enhancing pilot clinical trial validity when systematically assessing a range of medications and drug classes for potential utility in treatment of cocaine dependence. DESIGN: CREST utilizes a randomized, controlled, parallel group, blinded methodology for comparing one or more marketed medications against a standard, pharmaceutical grade placebo. The trial design is comprised of a flexible 24-week screening/baseline period followed by randomization to an 8-week treatment period. MEASURES: Standard measures of outcomes for the CREST included urinary benzoylecgonine (primary metabolite of cocaine), retention, cocaine craving, depression, clinical global impression and HIV-risk behaviors. In order to facilitate comparisons of data from the CREST studies across sites, drug classes and time, standardized procedures, measures and psychosocial counseling were used. RESULTS: A total of 19 medications were evaluated in out-patient treatment research clinics in Boston, Cincinnati, Los Angeles, New York and Philadelphia. CONCLUSIONS: Findings supported decisions to move forward three medications (cabergoline, reserpine, tiagabine) using full-scale, adequately powered, randomized placebo-controlled trial designs. Lessons learned from the CREST experience continue to shape cocaine pharmacotherapy trial design and execution.

Efficacy screening trials of paroxetine, pentoxifylline, riluzole, pramipexole and venlafaxine in cocaine dependence.

AIMS: The two studies presented here were conducted to assess the efficacy of paroxetine, pentoxifylline, riluzole, venlafaxine and pramipexole as medications for the treatment of cocaine dependence. DESIGN: A multi-arm, modified blinded, placebo-controlled design was used. SETTING: The studies were conducted at the Boston VA Healthcare System and the Boston University School of Medicine Medication Development Research Unit (MDRU). PARTICIPANTS: Participants met criteria for cocaine dependence during a 2-week screening period. INTERVENTION: Following random assignment to one of the treatment groups, subjects received active medication or placebo for 8 weeks in combination with cognitive behavioral counseling. In the first study the efficacy of the antidepressant paroxetine (20 mg daily), the phosphodiesterase inhibitor pentoxifylline (1200 mg daily) and the glutamate release inhibitor riluzole (100 mg daily) was assessed. The antidepressant venlafaxine (150 mg daily) and the dopamine agonist pramipexole (1.5 mg daily) were evaluated in the second study. MEASUREMENTS: Urine benzoylecgonine (BE) concentrations, self-report of cocaine use and global impression scores served as primary outcome measures. Secondary measures included assessments of cocaine craving and psychiatric functioning. Adverse events were monitored during the treatment period. FINDINGS: None of the active medications produced greater reductions in urine BE concentrations over the treatment period than did placebo. There were trends for BE levels to become reduced in the pentoxifylline group during the first 4 weeks of treatment and for Addiction Severity Index (ASI) drug composite scores to be lower in the pentoxyfylline group at end-point compared to the placebo group. Significant within-group reductions in reported cocaine use and craving were found for all treatment groups, but none of the active medications were superior to placebo on these measures. The accuracy of self-reported cocaine use declined over the study period. Overall, the active medications were well tolerated. CONCLUSIONS: This study does not support the use of paroxetine, pentoxifylline, riluzole, venlafaxine or pramipexole for the treatment of cocaine dependence. However, these results need to be interpreted with caution because of the small size and lack of homogeneity of the experimental groups.

A medication screening trial evaluation of reserpine, gabapentin and lamotrigine pharmacotherapy of cocaine dependence.

AIMS: To conduct a preliminary evaluation of the safety and efficacy of reserpine, gabapentin or lamotrigine versus an unmatched placebo control as a treatment for cocaine dependence. DESIGN: A 10-week out-patient study using the Cocaine Rapid Efficacy and Safety Trial (CREST) study design. SETTING: The study was conducted at the Cincinnati Medication Development Research Unit (MDRU). PARTICIPANTS: Participants met Diagnostic and Statistical Manual version IV (DSM-IV) criteria for cocaine dependence. Sixty participants were enrolled, with 50 participants completing the final study measures. INTERVENTION: The targeted daily doses of medication were reserpine 0.5 mg, gabapentin 1800 mg and lamotrigine 150 mg. All participants received 1 hour of manualized individual cognitive behavioral therapy on a weekly basis. MEASUREMENTS: Primary outcome measures of efficacy included urine benzoylecgonine (BE) level, Cocaine Clinical Global Impression scale--observer and self-report of cocaine use. Safety measures included adverse events, electrocardiograms (ECGs), vital signs and laboratory tests. FINDINGS: Subjective measures of cocaine dependence indicated significant improvement for all study groups. Urine BE results indicated a significant improvement for the reserpine group (P < 0.05) and non-significant changes for the other study groups. No pattern of physical or laboratory abnormalities attributable to treatment with any of the medications was identified. There were three serious adverse events reported, none of which were related to study procedures. The medications appeared to be tolerated well. CONCLUSIONS: The present findings suggest that reserpine may be worthy of further study as a cocaine dependence treatment.

A placebo-controlled screening trial of tiagabine, sertraline and donepezil as cocaine dependence treatments.

AIMS: To conduct a preliminary evaluation of the safety and efficacy of tiagabine, sertraline or donepezil versus an unmatched placebo control as a treatment for cocaine dependence. DESIGN: A 10-week out-patient study was conducted using the Cocaine Rapid Efficacy and Safety Trial (CREST) study design. SETTING: This study was conducted at the Cincinnati Medication Development Research Unit (MDRU) and at an affiliated site in Dayton, Ohio. PARTICIPANTS: Participants met Diagnostic and Statistical Manual version IV (DSM-IV) criteria for cocaine dependence. Sixty-seven participants were enrolled with 55 completing final study measures. INTERVENTION: The targeted daily doses of medication were tiagabine 20 mg, sertraline 100 mg and donepezil 10 mg. All participants received 1 hour of manualized individual cognitive behavioral therapy on a weekly basis. MEASUREMENTS: Primary outcome measures of efficacy included urine benzoylecgonine (BE) level, Cocaine Clinical Global Impression Scale-Observer and self-report of cocaine use. Safety measures included adverse events, ECGs, vital signs and laboratory tests. FINDINGS: Subjective measures of cocaine dependence indicated significant improvement for all study groups. Generalized estimating equations analysis indicated that the tiagabine group showed a trend toward a significant decrease in urine BE level from baseline to weeks 5-8 (P = 0.10) and non-significant changes for the other study groups. No pattern of physical or laboratory abnormalities attributable to treatment with any of the medications was identified. There were three serious adverse events reported, none of which were related to study procedures. CONCLUSIONS: The present findings suggest that tiagabine may be worthy of further study as a cocaine dependence treatment.

Safety and health policy considerations related to the use of buprenorphine/naloxone as an office-based treatment for opiate dependence.

Opiate dependence remains a fundamental challenge confronting health delivery systems and is often characterized as a social and moral issue. The impact of this disorder on healthcare policy is changing with the increased incidence of HIV, hepatitis C, and tuberculosis infections in opiate-dependent patients. These medical illnesses have substantial effect on escalating healthcare costs, and, therefore, also affect healthcare policy priorities, which are responsive to these costs. Pharmacological treatments for opiate dependence have had limited success; often the consequence of limited access to care. Hence, there is a need to develop new pharmacotherapies for opiate dependence that extend the range of clinical options, including new first-line treatment approaches. This paper will focus on the safety and health policy considerations related to the use of buprenorphine and buprenorphine/naloxone based on data derived from clinical trials and post-marketing surveillance that provide evidence for the use of the medications as first-line treatments in an office-based environment. The evaluation of this evidence formed the basis by the National Institute on Drug Abuse to support and pursue the evaluation and registration of buprenorphine/naloxone and buprenorphine in a public/private sector cooperative effort to become an office-based, first-line treatment for opiate dependence.