Maintenance treatment for opioid dependence with slow-release oral morphine: a randomized cross-over, non-inferiority study versus methadone

Adaptive Designs for Non-inferiority Trials with Multiple Experimental Treatments

The increase in the popularity of non-inferiority clinical trials represents the increasing need to search for substitutes for some reference (standard) treatments. A new treatment would be preferred to the standard treatment if the benefits of adopting it outweigh a possible clinically insignificant reduction in treatment efficacy (non-inferiority margin). Statistical procedures have recently been developed for treatment comparisons in non-inferiority clinical trials that have multiple experimental (new) treatments. An ethical concern for non-inferiority trials is that some patients undergo the less effective treatments; this problem is more serious when multiple experimental treatments are included in a balanced trial in which the sample sizes are the same for all experimental treatments. With the aim of giving fewer patients the inferior treatments, we propose a response-adaptive treatment allocation scheme that is based on the doubly adaptive biased coin design. The proposed adaptive design is also shown to be superior to the balanced design in terms of testing power.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Treatment-refractory substance use disorder: Focus on alcohol, opioids, and cocaine

Substance use disorders are common, but only a small minority of patients receive adequate treatment. Although psychosocial therapies are effective, relapse is common. This review focusses on novel pharmacological and other treatments for patients with alcohol, opioid, or cocaine use disorders who do not respond to conventional treatments. Disulfiram, acamprosate, and the opioid antagonist naltrexone have been approved for the treatment of alcoholism. A novel, "as needed" approach is the use of the mu-opioid antagonist and partial kappa agonist nalmefene to reduce alcohol consumption. Other novel pharmacological approaches include the GABA-B receptor agonist baclofen, anticonvulsants such as topiramate and gabapentin, the partial nicotine receptor agonist varenicline, and other drugs. For opioid dependence, opioid agonist therapy with methadone or buprenorphine is the first-line treatment option. Other options include oral or depot naltrexone, morphine sulfate, depot or implant formulations, and heroin (diacetylmorphine) in treatment-refractory patients. To date, no pharmacological treatment has been approved for cocaine addiction; however, 3 potential pharmacological treatments are being studied, disulfiram, methylphenidate, and modafinil. Pharmacogenetic approaches may help to optimize treatment response in otherwise treatment-refractory patients and to identify which patients are more likely to respond to treatment, and neuromodulation techniques such as repeated transcranial magnetic stimulation and deep brain stimulation also may play a role in the treatment of substance use disorders. Although no magic bullet is in sight for treatment-refractory patients, some novel medications and brain stimulation techniques have the potential to enrich treatment options at least for some patients.

Testing of non-inferiority and superiority for three-arm clinical studies with multiple experimental treatments

The purpose of a non-inferiority trial is to assert the efficacy of an experimental treatment compared with a reference treatment by showing that the experimental treatment retains a substantial proportion of the efficacy of the reference treatment. Statistical methods have been developed to test multiple experimental treatments in three-arm non-inferiority trials. In this paper, we report the development of procedures that simultaneously test the non-inferiority and the superiority of experimental treatments after the assay sensitivity has been established. The advantage of the proposed test procedures is the additional ability to identify superior treatments while retaining an non-inferiority testing power comparable to that of existing testing procedures. Single-step and stepwise procedures are derived and then compared with each other to determine their relative testing power and testing error in a simulation study. Finally, the suggested procedures are illustrated with two clinical examples.

Sustained release oral morphine as an alternative to methadone for the treatment of opioid-use disorder post Torsades de Pointes cardiac arrest

In most settings, approved medications for the treatment of opioid-use disorder include methadone and buprenorphine/naloxone, and in some settings, naltrexone. We present a case in which methadone administration was associated with an in-hospital episode of Torsades de Pointes in a patient who was subsequently maintained on sustained release oral morphine (SROM) for treatment of his opioid-use disorder. This transition was made in the context of long-term compliance to methadone maintenance, and with a previous adverse reaction to buprenorphine/naloxone precluding its use. The change to SROM, supported by emerging evidence, resulted in a reduction in the patient's measured QTc interval, prevention of further arrhythmias and continued abstinence from illicit opioid-use. In this context, we believe careful consideration should be given to the use of SROM.

Self-reported cravings for heroin and cocaine during maintenance treatment with slow-release oral morphine compared with methadone: a randomized, crossover clinical trial

OBJECTIVE

Craving, an urge or increased desire to take a drug, is part of a cluster of behavioral, cognitive, and physiological phenomena that can develop after substance use. Self-reported cravings for heroin and cocaine are compared in opioid dependent patients while receiving maintenance treatment with slow-release oral morphine (SROM) or methadone.

METHODS

Data from a 22-week open-label, randomized, crossover trial (per protocol sample n = 157) were examined by analysis of variance (ANOVA). Cravings for heroin and cocaine during the past 7 days were assessed at baseline and thrice during each 11-week treatment period using a Visual Analog Scale (heroin, VAS-H; cocaine, VAS-C), German versions of the brief Heroin Craving Questionnaire (HCQ), and the brief Cocaine Craving Questionnaire (CCQ).

RESULTS

Mean (SD) heroin craving scores under methadone were 3.3 (2.4) (VAS-H) and 2.9 (1.4) (HCQ). Heroin craving scores under SROM were significantly lower, at 2.5 (2.2) (VAS-H) and 2.6 (1.2) (HCQ) (ANOVA: VAS-H P < 0.0001, HCQ P = 0.010). Cocaine craving scores were not significantly different (methadone: 1.6 (2.0) (VAS-C) and 2.1 (1.2) (CCQ) vs SROM: 1.4 (1.9) (VAS-C) and 2.1 (1.2) (CCQ); ANOVA: VAS-C P = 0.175, CCQ P = 0.536). No significant carry-over effects were detected.

CONCLUSIONS

This study demonstrates that SROM is clinically more effective than methadone in reducing general craving for heroin during opioid maintenance treatment while not affecting cocaine craving.

Noninferiority studies with multiple reference treatments

The increasing popularity of noninferiority trials reflects the ongoing efforts to replace existing treatments (reference treatments) with new treatments (experimental treatments) that retain a substantial fraction of the effect of the reference treatments. The adoption of any new treatment has to be vindicated by a demonstration of benefits that outweigh a possible clinically insignificant reduction in the reference treatment efficacy. Statistical methods have been developed to analyze data collected from noninferiority trials. However, these methods focus on cases with only one reference treatment. In this paper, we provide the statistical inferential procedures for situations with multiple reference treatments. The computation of the corresponding critical values for simultaneous testings of noninferiority of several new treatments to multiple reference treatments in the presence of a placebo is provided. Furthermore, for a prespecified level of test power, a technique to determine the optimal sample size before the onset of a noninferiority trial is derived. A clinical example is given to illustrate our proposed procedure.

Mental symptoms and drug use in maintenance treatment with slow-release oral morphine compared to methadone: results of a randomized crossover study

BACKGROUND

Opioid maintenance treatment is the option of choice to stabilize opioid-dependent patients. Whilst efficacy of methadone and buprenorphine has been studied extensively, fewer data on slow-release oral morphine are available.

AIMS

This study analyzes the effects of slow-release oral morphine compared to methadone with regard to self-reported mental symptoms, drug use and satisfaction with treatment.

METHODS

The study was carried out as an open-label randomized crossover trial in 14 treatment sites in Switzerland and Germany. It comprised 2 crossover periods of 11 weeks each. For measuring mental symptoms, the Symptom Checklist-27 (SCL-27) was used. Drug and alcohol use was assessed by the number of consumption days, and treatment satisfaction by a visual analogue scale.

RESULTS

A total of 157 patients were included for the analyses (per-protocol sample). Statistically significantly better outcomes for morphine as compared to methadone treatment were found for overall severity of mental symptoms (SCL-27 Global Severity Index), as well as 5 of the 6 syndrome groups of the SCL-27, and for treatment satisfaction. There were no statistically significant differences with regard to drug or alcohol use between groups.

CONCLUSIONS

This study supports positive effects of slow-release oral morphine compared to methadone on patient-reported outcomes such as mental symptoms and treatment satisfaction with comparable effects on concomitant drug use. Slow-release oral morphine represents a meaningful alternative to methadone for treatment of opioid dependence.