Eric C. Strain

Buprenorphine versus methadone in the treatment of opioid dependence : self-reports, urinalysis, and addiction severity index

This article reports results for patients who completed the 16-week maintenance phase of a double-blind clinical trial comparing buprenorphine (N = 43; average dose = 9.0 mg/day sublingually) with methadone (N = 43; average dose = 54 mg/day orally) in the outpatient treatment of opioid dependence. In addition to pharmacotherapy, treatment during the clinical trial included individual counseling, weekly group therapy, and on-site medical services. Patients in both medication groups showed significant and substantial improvements over time in areas of psychosocial functioning, as assessed by the Addiction Severity Index, rates of urinalysis tests positive for opioids, and self-reports of opioid withdrawal symptoms, illicit opioid use, and cocaine use. Buprenorphine and methadone produced very similar outcomes on the wide array of outcome measures assessed, and improvements for both groups were large and occurred rapidly after treatment entry. A trend toward continued improvement in opioid-positive urines over time was noted for the buprenorphine but not the methadone group. These results provide further evidence of the efficacy of buprenorphine in the treatment of opioid dependence and provide a characterization of the time course of effects for buprenorphine and methadone. In addition, these results demonstrate the benefits of drug abuse treatment, both for drug and alcohol use and in other areas of psychosocial functioning.

Decreased frontal white-matter volume in chronic substance abuse

There is quite a body of work assessing functional brain changes in chronic substance abuse, much less is known about structural brain abnormalities in this patient population. In this study we used magnetic resonance imaging (MRI) to determine if structural brain differences exist in patients abusing illicit drugs compared to healthy controls. Sixteen substance abusers who abused heroin, cocaine and cannabis but not alcohol and 16 age-, sex- and race-matched controls were imaged on a MRI scanner. Contiguous, 5-mm-thick axial slices were acquired with simultaneous T2 and proton density sequences. Volumes were estimated for total grey and white matter, frontal grey and white matter, ventricles, and CSF using two different methods: a conventional segmentation and a stereological method based on the Cavalieri principle. Overall brain volume differences were corrected for by expressing the volumes of interest as a percentage of total brain volume. Volume measures obtained with the two methods were highly correlated (r=0.65, p<0.001). Substance abusers had significantly less frontal white-matter volume percentage than controls. There were no significant differences in any of the other brain volumes measured. This difference in frontal lobe white matter might be explained by a direct neurotoxic effect of drug use on white matter, a pre-existing abnormality in the development of the frontal lobe or a combination of both effects. This last explanation might be compelling based on the fact that newer concepts on shared aspects of some neuropsychiatric disorders focus on the promotion and inhibition of the process of myelination throughout brain development and subsequent degeneration.

Clustering of multiple substance use and psychiatric diagnoses in opiate addicts

Using a standardized psychiatric interview, the prevalence of and interrelationships among various substance use diagnoses and non-substance use psychiatric diagnoses were examined in a population of opiate addicts (n = 66) enrolled in methadone maintenance treatment. Multiple substance use disorders were found in these patients, and more substance use disorders were found in those patients with, versus without, a non-substance use psychiatric diagnosis. Certain substance use disorders were found to cluster. These results suggest that opiate addicts should be evaluated for multiple substance use disorders as well as for non-substance use disorders, and that certain subpopulations may be at increased risk for multiple substance use disorders.

Enhancement of cocaine's abuse liability in methadone maintenance patients

The present study was conducted to determine whether methadone maintenance alters the pharmacodynamic effects of single doses of cocaine. Twenty-two current users of IV cocaine who were not seeking treatment for their illicit cocaine use participated while living on a research unit. Eleven were maintained on methadone 50 mg PO daily as treatment for their opioid abuse; 11 were opioid abusers who were not physically dependent on opioids and who provided opioid-free urines throughout the study. Each subject received acute cocaine challenge doses of 0, 12.5, 25, and 50 mg intravenously in random order under double-blind conditions in separate test sessions. Physiologic and subject-rated responses were measured before injection and for 2 h after. In the methadone maintenance group, cocaine challenge sessions occurred 15.5 h after the daily methadone dose. There were significant differences between the methadone-dependent and nondependent groups: 1) baseline differences related to chronic methadone administration and not associated with cocaine administration (lower respiration rates and pupil diameter; higher skin temperature) and 2) differences in response to cocaine administration; cocaine-induced increases in subject ratings of Drug Effect, Rush, Good Effects, Liking, and Desire for Cocaine and in heart rate were greater in the methadone maintenance patients compared to the non-dependent group. These results indicate that the positive subjective effects and some physiological effects of cocaine are enhanced in methadone-maintained individuals, suggesting a pharmacological basis for the high rates of cocaine abuse among methadone maintenance patients.

Induction of opioid-dependent individuals onto buprenorphine and buprenorphine/naloxone soluble-films

A sublingual soluble‐film formulation of buprenorphine/naloxone (B/N) has been approved by the US Food and Drug Administration for the treatment of opioid dependency. This preparation provides unit‐dose, child‐resistant packaging amenable to tracking and accountability, offers more rapid dissolution, and has a potentially preferred taste vs. tablets. This study compared the ability of buprenorphine (B) and B/N films to suppress spontaneous withdrawal in opioid‐dependent volunteers. Participants were maintained on morphine and underwent challenge sessions to confirm sensitivity to naloxone‐induced opioid withdrawal. Subjects were randomized to receive either B (16 mg, n = 18) or B/N (16/4 mg, n = 16) soluble films for 5 days. The primary outcome measure was the Clinical Opiate Withdrawal Scale (COWS) score. Thirty‐four subjects completed induction onto soluble films. There was a significant decrease in COWS scores but no significant differences between the groups. The results support the use of B and B/N soluble films as safe and effective delivery methods for opioid induction.

The association between outpatient buprenorphine detoxification duration and clinical treatment outcomes: A review

BACKGROUND The association between buprenorphine taper duration and treatment outcomes is not well understood. This review evaluated whether duration of outpatient buprenorphine taper is significantly associated with treatment outcomes. METHODS Studies that were published in peer-reviewed journals, administered buprenorphine as an outpatient taper to opioid-dependent participants, and provided data on at least one of three primary treatment outcome measures (opioid abstinence, retention, peak withdrawal severity) were reviewed. Primary treatment outcomes were evaluated as a function of taper duration using hierarchical linear regressions with pre-taper maintenance duration as a cofactor. RESULTS Twenty-eight studies were reviewed. Taper duration significantly predicted percent of opioid-negative samples provided during treatment, however pre-taper maintenance period predicted percent participants abstinent on the final day of treatment. High rates of relapse were reported. No significant association between taper duration and retention in treatment or peak withdrawal severity was observed. CONCLUSION The data reviewed here suggest taper duration is associated with opioid abstinence achieved during detoxification but not with other markers of treatment outcome. The reviewed studies varied widely on several parameters (e.g., frequency of urinalysis testing, provision of ancillary medications) that may influence treatment outcome and thus could have interfered with the ability to identify relationships between taper duration and outcomes. Future studies evaluating opioid detoxification should utilize rigorous experimental methods and report a wider range of outcome measures in order to help advance our understanding of the association between taper duration and treatment outcomes.

A randomized controlled trial of fluoxetine in the treatment of cocaine dependence among methadone-maintained patients

BACKGROUND Cocaine abuse and dependence continue to be widespread. Currently, there are no pharmacotherapies shown to be effective in the treatment of cocaine dependence. METHODS A 33-week outpatient clinical trial of fluoxetine (60 mg/day, po) for cocaine dependence that incorporated abstinence-contingent voucher incentives was conducted. Participants (N = 145) were both cocaine and opioid dependent and treated with methadone. A stratified randomization procedure assigned subjects to one of four conditions: fluoxetine plus voucher incentives (FV), placebo plus voucher incentives (PV), fluoxetine without vouchers (F), and placebo without vouchers (P). Dosing of fluoxetine/placebo was double blind. Primary outcomes were treatment retention and cocaine use based on thrice-weekly urine testing. RESULTS The PV group had the longest treatment retention (M = 165 days) and lowest probability of cocaine use. The adjusted predicted probabilities of cocaine use were 65% in the P group, 60% in the F group, 56% in the FV group, and 31% in the PV group. CONCLUSIONS Fluoxetine was not efficacious in reducing cocaine use in patients dually dependent on cocaine and opioids.

Sublingual buprenorphine/naloxone for chronic pain in at-risk patients: Development and pilot test of a clinical protocol

OBJECTIVE Sublingual buprenorphine/naloxone (Bup/Nx) is approved for addiction treatment and may be useful for pain management, particularly in opioid-treated patients with pain with nonadherence behaviors. The transition of opioid-treated patients with pain to buprenorphine carries the risk of precipitated withdrawal and increased pain. This study convened pain and addiction specialists to develop and pilot a clinical protocol for safe transitioning to Bup/Nx. DESIGN The protocol was revised three times based on outside expert review and pilot study observations. The pilot was conducted with a prospective cohort of 12 patients with moderate to severe chronic pain, who were receiving long-term opioid therapy with any full m-agonist drug, and had exhibited one or more aberrant drug-related behaviors. Patients were followed up for 3-6 months with the expectation that they would experience few adverse events (AEs) and report lower pain severity. RESULTS The three patients on the highest baseline opioid dose (equivalent to 303-450 mg of oral morphine) and the three on the lowest doses (≤20 mg) had early AEs when switched to Bup/Nx and did not complete the trial. Of the remaining six, one withdrew due to AEs; one responded well, then withdrew; and four completed a 3-month trial. A mixed-effects model controlling for dropouts found that average and worst pain significantly decreased after the switch to Bup/Nx (both p < 0.01). CONCLUSION Based on this experience, the protocol recommends Bup/Nx for pain only when baseline opioid doses are within bounds that reduce AEs at transition and incorporates dose flexibility to further reduce risks. This protocol warrants further testing.

Correlates of nonmedical use of stimulants and methamphetamine use in a national sample

BACKGROUND Despite chemical similarities, ADHD stimulants and methamphetamine have distinct use patterns in the community. This study compared the characteristics of nonmedical ADHD stimulants users and methamphetamine users in a household sample. METHODS In data from the 2009-2011 National Survey on Drug Use and Health, adult and adolescent stimulant users were categorized into three mutually exclusive subgroups: nonmedical ADHD stimulant users only (STM users), methamphetamine users (METH users), and both nonmedical ADHD stimulant and methamphetamine users (STM/METH users). Multivariate logistic regression analyses identified the substance comorbidity, mental health, and deviant behavior characteristics associated with these three groups. RESULTS Compared to adolescent STM users, STM/METH users were more likely to be female, younger and uninsured while METH users were more likely to be younger, in a minority group and from a higher-income family. Compared to adult STM users, METH and STM/METH users were more likely to be male, older, uninsured, no longer married, and to be from rural areas. Adolescent METH users were more likely than STM users to report illegal drug use while adult METH users were less likely to report prescription drug use than their STM user counterparts. Overall, adult and adolescent STM/METH users were more likely to report substance use, mental health problems and deviant behaviors compared to STM users. CONCLUSION The characteristics of STM users differ from METH and STM/METH users, and their associations with substance use and psychiatric comorbidities differ by age. Findings have implications for understanding the risks for stimulant use in different age subgroups.

Measures of outcome for stimulant trials: ACTTION recommendations and research agenda.

BACKGROUND The development and approval of an efficacious pharmacotherapy for stimulant use disorders has been limited by the lack of a meaningful indicator of treatment success, other than sustained abstinence. METHODS In March, 2015, a meeting sponsored by Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) was convened to discuss the current state of the evidence regarding meaningful outcome measures in clinical trials for stimulant use disorders. Attendees included members of academia, funding and regulatory agencies, pharmaceutical companies, and healthcare organizations. The goal was to establish a research agenda for the development of a meaningful outcome measure that may be used as an endpoint in clinical trials for stimulant use disorders. RESULTS AND CONCLUSIONS Based on guidelines for the selection of clinical trial endpoints, the lessons learned from prior addiction clinical trials, and the process that led to identification of a meaningful indicator of treatment success for alcohol use disorders, several recommendations for future research were generated. These include a focus on the validation of patient reported outcome measures of functioning, the exploration of patterns of stimulant abstinence that may be associated with physical and/or psychosocial benefits, the role of urine testing for validating self-reported measures of stimulant abstinence, and the operational definitions for reduction-based measures in terms of frequency rather than quantity of stimulant use. These recommendations may be useful for secondary analyses of clinical trial data, and in the design of future clinical trials that may help establish a meaningful indicator of treatment success.