Cannabidiol and substance use disorder: Dream or reality

BACKGROUND

Cannabidiol (CBD) is one of the major constituents of Cannabis sativa L. that lacks psychotomimetic and rewarding properties and inhibits the rewarding and reinforcing effects of addictive drugs such as cocaine, methamphetamine (METH), and morphine. Additionally, CBD's safety profile and therapeutic potential are currently evaluated in several medical conditions, including pain, depression, movement disorders, epilepsy, multiple sclerosis, Alzheimer's disease, ischemia, and substance use disorder. There is no effective treatment for substance use disorders such as addiction, and this review aims to describe preclinical and clinical investigations into the effects of CBD in various models of opioid, psychostimulant, cannabis, alcohol, and nicotine abuse. Furthermore, the possible mechanisms underlying the therapeutic potential of CBD on drug abuse disorders are reviewed.

METHODS

The current review considers and summarizes the preclinical and clinical investigations into CBD's effects in various models of drug abuse include opioids, psychostimulants, cannabis, alcohol, and nicotine.

RESULTS

Several preclinical and clinical studies have proposed that CBD may be a reliable agent to inhibit the reinforcing and rewarding impact of drugs.

CONCLUSIONS

While the currently available evidence converges to suggest that CBD could effectively reduce the rewarding and reinforcing effects of addictive drugs, more preclinical and clinical studies are needed before CBD can be added to the therapeutic arsenal for treating addiction.

Evaluation of FDA Boxed Warning on Prescribing Patterns of Fluoroquinolones for Uncomplicated Urinary Tract Infections

Background: Little is known regarding the impact of the Food and Drug Administration (FDA) boxed warning on prescribing rates of fluoroquinolone (FQ) antibiotics in the outpatient setting. Objective: The primary objective of this study was to evaluate the 2016 FDA boxed warning update on FQ prescribing rates for uncomplicated urinary tract infection (uUTI). Methods: This was a single-center retrospective cohort study conducted at 6 family medicine practices, including women aged 18 to 65 years with an outpatient visit for uUTI from January 1, 2016, to December 31, 2016. Results: A total of 436 patients met inclusion. FQs were prescribed in 38% of patients before the FDA boxed warning and in 30% of patients after (8% reduction). Non-FQ prescribing had a corresponding 8% increase, comprising 62% of uUTI prescribing before the FDA boxed warning and 70% after (P = 0.08). The likelihood of being prescribed a FQ was not significantly different following release of the FDA boxed warning (adjusted odds ratio = 0.67 [95% CI = 0.41-1.10]). Variables significantly associated with an increase in FQ prescribing based on logistic regression were age ≥58 years and chronic kidney disease. Concordance of antibiotic prescribing with the Infectious Diseases Society of America clinical practice guidelines for uUTI was low, and the incidence of treatment failure was low. Conclusion and Relevance: The 2016 FDA boxed warning was not significantly associated with decreased FQ prescribing for uUTI across a large academic family medicine practice. Methods to improve education and disseminate FDA warnings in practice are needed.

Long QTc During Methadone Maintenance: Contributors and Interventions Over 4 Years

Our goal consisted of describing the 4-year prevalence, contributors, and interventions for long QTc's in methadone maintenance treatment. Cardiologists' diagnosis of long QTc defined case-ness in 62 patients. Long QTc categories, drawn from epidemiological reports, encompassed 440 to 469 (borderline), 470 to 499 (moderate), and 500+ milliseconds (severe). Data collection included electrocardiograms, demographic characteristics, contributors to long QTc, and interventions-plus-outcomes (defined by resolution of long QTc). Of 62 patients, 21 had 39 long QTc episodes-a 4-year case prevalence of 34%, and an annual episode incidence of 15.7 per 100. Contributing factors identified in 36 of 39 episodes consisted of medication management (n = 19), illicit drug use (n = 11), and other factors (n = 6). Long QTc reverted to normal in 38 of 39 episodes. Of 21 patients, 12 (57%) experienced one or two recurrences. Methadone maintenance treatment physicians normalized most episodes as outpatients, often in collaboration with patients' primary care physicians. One fifth of episodes required hospitalization and other specialty care. Lack of timely QTc normalization may have accounted for one sudden death.

Trends in reporting methadone-associated cardiac arrhythmia, 1997-2011: an analysis of registry data

BACKGROUND

Long-acting opioids are a leading cause of accidental death in the United States, and methadone is associated with greater mortality rates. Whether this increase is related to the proarrhythmic properties of methadone is unclear.

OBJECTIVE

To describe methadone-associated arrhythmia events reported in the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS).

DESIGN

Description of national adverse event registry data before and after publication of a 2002 report describing an association between methadone and arrhythmia.

SETTING

FAERS, November 1997 and June 2011.

PATIENTS

Adults with QTc prolongation or torsade de pointes and ventricular arrhythmia or cardiac arrest.

MEASUREMENTS

FAERS reports before and after the 2002 report.

RESULTS

1646 cases of ventricular arrhythmia or cardiac arrest and 379 cases of QTc prolongation or torsade de pointes were associated with methadone. Monthly reports of QTc prolongation or torsade de pointes increased from a mean of 0.3 (95% CI, 0.1 to 0.5) before the 2002 publication to a mean of 3.5 (CI, 2.5 to 4.8) after it. After 2000, methadone was the second-most common primary suspect in cases of QTc prolongation or torsade de pointes after dofetilide (a known proarrhythmic drug) and was associated with disproportionate reporting similar to that of antiarrhythmic agents known to promote torsade de pointes. Antiretroviral drugs for HIV were the most common coadministered drugs.

LIMITATION

Reports to FAERs are voluntary and selective, and incidence rates cannot be determined from spontaneously reported data.

CONCLUSION

Since 2002, reports to FAERS of methadone-associated arrhythmia have increased substantially and are disproportionately represented relative to other events with the drug. Coadministration of methadone with antiretrovirals in patients with HIV may pose particular risk.

PRIMARY FUNDING SOURCE

Colorado Clinical and Translational Sciences Institute, National Institutes of Health, and Agency for Healthcare Research and Quality.

Agreement between ICU clinicians and electrophysiology cardiologists on the decision to initiate a QTc-interval prolonging medication in critically ill patients with potential risk factors for torsade de pointes: a comparative, case-based evaluation

STUDY OBJECTIVES

To measure concordance between different intensive care unit (ICU) clinicians and a consensus group of electrophysiology (EP) cardiologists for use of a common rate-corrected QT interval (QTc)-prolonging medication in cases containing different potential risk factor(s) for torsade de pointes (TdP).

DESIGN

Prospective case-based evaluation.

SETTING

Academic medical center with 320 beds.

SUBJECTS

Medical house staff (MDs) and ICU nurses (RNs) from one center and select critical care pharmacists (PHs).

INTERVENTION

Completion of a survey containing 10 hypothetical ICU cases in which patients had agitated delirium for which a psychiatrist recommended intravenous haloperidol 5 mg every 6 hours. Each case contained different potential risk factor(s) for TdP in specific combinations. A group of five EP cardiologists agreed that haloperidol use was safe in five cases and not safe in five cases.

MEASUREMENTS AND MAIN RESULTS

For each case, participants were asked to document whether they would administer haloperidol, to provide a rationale for their decision, and to state their level of confidence in that decision. Most clinicians (92 of 115 [80%]) invited to participate completed the cases. Among the five cases where EP cardiologists agreed that haloperidol was not safe, 29% of respondents felt that haloperidol was safe. Conversely, in the five cases where EP cardiologists felt haloperidol was safe, 21% of respondents believed that it was not safe. Overall respondent-EP cardiologist agreement for haloperidol use across the 10 cases was moderate (κ = 0.51). MDs and PHs were in agreement with the EP cardiologists more than RNs (p=0.03). Interprofessional variability existed for the TdP risk factors each best identified. Clinician confidence correlated with EP cardiologist concordance for MDs (p=0.002) and PHs (p=0.0002), but not for RNs (p=0.69).

CONCLUSION

When evaluating use of a QTc interval-prolonging medication, ICU clinicians often fail to identify the TdP risk factors that EP cardiologists feel should prevent its use. Clinician-EP cardiologist concordance varies by the specific risk factor(s) for TdP and the ICU professional conducting the assessment.

Attitudes and practices of pediatric oncologists regarding methadone use in the treatment of cancer-related pain: results of a North American Survey

Methadone is effective in the treatment of cancer-related pain in adults. Pediatric oncologists may be reluctant to use methadone, given the paucity of existing research and a lack of familiarity with its use. This study's purpose was to assess pediatric oncologists' experience, comfort and practice of methadone prescription, and determine interest in and appropriate venues for education on methadone. A 22-item survey was sent by electronic mail to 1912 practicing pediatric oncologists. Six hundred thirty-one pediatric oncologists (33%) responded to the survey. Seventy-two percent of respondents reported they prescribe methadone to <10% of their patients receiving opioids. Physicians practicing ≥10 years (84% vs. 76%, P=0.01), at centers that see ≥100 new patients per year (86% vs. 76%, P=0.003), or who have received prior education on methadone (89% vs. 54%, P<0.001) were more likely to have prescribed methadone. The primary reasons respondents did not utilize methadone included a lack of knowledge of methadone's pharmacodynamics (39%), effectiveness (39%), and/or dosing equivalence (34%). Perceived competence with dose equivalence, belief that methadone is effective, and working in a division where >20 patients per year died were all independently associated with having prescribed methadone to >10% of patients on opioids. Eighty-five percent of respondents would like additional education on methadone. Many pediatric oncologists lack experience and education in the use of methadone. Formal education initiatives should be implemented to enhance pediatric oncologists' comfort and expertise in methadone use.

Buprenorphine vs methadone treatment: A review of evidence in both developed and developing worlds

Heroin dependence is a major health and social problem associated with increased morbidity and mortality that adversely affects social circumstances, productivity, and healthcare and law enforcement costs. In the UK and many other Western countries, both methadone and buprenorphine are recommended by the relevant agencies for detoxification from heroin and for opioid maintenance therapy. However, despite obvious benefits due to its unique pharmacotherapy (eg, greatly reduced risk of overdose), buprenorphine has largely failed to overtake methadone in managing opioid addiction. The experience from the developing world (based on data from India) is similar. In this article we compare the advantages and disadvantages of the use methadone and buprenorphine for the treatment of opioid addiction from both a developed and developing world perspective; and explore some of the reasons why buprenorphine has not fulfilled the expectations predicted by many in the addictions field.

QT interval screening in methadone maintenance treatment: report of a SAMHSA expert panel

In an effort to enhance patient safety in opioid treatment programs, the Substance Abuse and Mental Health Saervices Administration convened a multi-disciplinary Expert Panel on the Cardiac Effects of Methadone. Panel members (Appendix A) reviewed the literature, regulatory actions, professional guidances, and opioid treatment program experiences regarding adverse cardiac events associated with methadone. The Panel concluded that, to the extent possible, every opioid treatment program should have a universal Cardiac Risk Management Plan (incorporating clinical assessment, electrocardiogram assessment, risk stratification, and prevention of drug interactions) for all patients and should strongly consider patient-specific risk minimization strategies (such as careful patient monitoring, obtaining electrocardiograms as indicated by a particular patient's risk profile, and adjusting the methadone dose as needed) for patients with identified risk factors for adverse cardiac events. The Panel also suggested specific modifications to informed consent documents, patient education, staff education, and methadone protocols.

A continuing black hole? The FDA boxed warning: an appeal to improve its clinical utility

The boxed warning is increasingly utilized by the Food and Drug Administration (FDA) as a clinical warning to prescribers of dangerous adverse drug reactions. As these warnings have expanded, we feel the utility and application of boxed warnings are becoming more nebulous. The use of drugs following issuance of a boxed warning has been variable. Droperidol sales decreased 10-fold in the year following the warning, yet there has been essentially no change in the methadone usage over a similar time period after its boxed warning. Including more information, such as estimation of incidence for the adverse drug reaction, would be more clinically useful to the prescriber. Reasonable standards using supplemental databases outside of the FDA (such as national poison center data) could be helpful in developing an integrated and balanced approach to boxed warnings.

The World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the biological treatment of substance use and related disorders. Part 2: Opioid dependence

OBJECTIVES

To develop evidence-based practice guidelines for the pharmacological treatment of opioid abuse and dependence.

METHODS

An international task force of the World Federation of Societies of Biological Psychiatry (WFSBP) developed these practice guidelines after a systematic review of the available evidence pertaining to the treatment of opioid dependence. On the basis of the evidence, the Task Force reached a consensus on practice recommendations, which are intended to be clinically and scientifically meaningful for physicians who treat adults with opioid dependence. The data used to develop these guidelines were extracted primarily from national treatment guidelines for opioid use disorders, as well as from meta-analyses, reviews, and publications of randomized clinical trials on the efficacy of pharmacological and other biological treatments for these disorders. Publications were identified by searching the MEDLINE database and the Cochrane Library. The literature was evaluated with respect to the strength of evidence for efficacy, which was categorized into one of six levels (A-F).

RESULTS

There is an excellent evidence base supporting the efficacy of methadone and buprenorphine or the combination of buprenorphine and naloxone for the treatment of opioid withdrawal, with clonidine and lofexidine as secondary or adjunctive medications. Opioid maintenance with methadone and buprenorphine is the best-studied and most effective treatment for opioid dependence, with heroin and naltrexone as second-line medications.

CONCLUSIONS

There is enough high quality data to formulate evidence-based guidelines for the treatment of opioid abuse and dependence. This task force report provides evidence for the efficacy of a number of medications to treat opioid abuse and dependence, particularly the opioid agonists methadone or buprenorphine. These medications have great relevance for clinical practice.

Cardiotoxicity of Oral Methadone as an Analgesic–-Recommendations for Safe Use

Once used only as third-line therapy in the management of chronic pain states, methadone is now being used as first- and second-line therapy. Most risks and the stigma associated with methadone use have been known for years. Only over the past decade or so have the unique pharmacokinetic-pharmacodynamic properties and methods for conversion from other opioids to methadone been established. Pertinent English-language literature was obtained from MEDLINE/PUBMED and EMBASE searches (1966-June 2009). This paper provides an overview of the cardiotoxicity of oral methadone, with an emphasis on its use as an analgesic. Cardiotoxicity during its use in the maintenance of opioid addiction has also been reviewed due to the wealth of epidemiologic, risk factor, and correlative analytic data contained therein. A series of recommendations are provided to improve the cardiac safety profile of oral methadone used for analgesia. In addition, there is a discussion of settings and patient types which may impact upon these recommendations.

Drug-induced torsades de pointes: data mining of the public version of the FDA Adverse Event Reporting System (AERS)

AIMS

To investigate spontaneous reports of TdP present in the public version of the FDA Adverse Event Reporting System (AERS) in the light of what is already known on their TdP-liability.

METHODS

Reports of TdP from January 2004 through December 2007 were retrieved from the public version of the AERS database. All reports were selected from REACTION files and the relevant suspected and/or interacting drugs were identified from DRUG files. Qualitative analysis was performed by the case/non-case method. Cases were represented by TdP reports, whereas non-cases were all reports of adverse drug reactions other than TdP. Quantitative analysis was assessed by calculating the crude and adjusted reporting odds ratio (ROR), as a measure of disproportionality, with the 95% confidence interval.

RESULTS

Reports of TdP were 1665 over a 4-year period, involving 376 active substances. Thirty-five drugs with at least 10 reports were identified: amiodarone and methadone were associated with the highest number of cases (113 and 83 respectively) and most of the other reports were ascribable to antibacterials, antidepressants and antipsychotics; remarkable differences in number of cases and ROR were present among agents within each therapeutic class. A disproportionate reporting was also observed for other compounds such as donepezil, famotidine and mitoxantrone.

CONCLUSIONS

Large spontaneous reporting databases represent an important source for signal detection of rare adverse drug reactions (ADR), such as TdP. The number of reports associated to donepezil, famotidine and mitoxantrone could be considered unexpected on the basis of current evidence and needs further investigations on their true TdP-liability.

Methadone analgesia for children with advanced cancer

BACKGROUND

Methadone is frequently used in the treatment of adults with advanced cancer. A criticism of relevant research is the use of single or fixed doses, which does not reflect use in clinical practice. Literature about use of methadone in the treatment of pediatric patients is limited to case reports. The objective of this study is to describe methadone use as primary opioid analgesic for advanced pediatric cancer over a 6.5-year period.

PROCEDURE

All 17 patients who received methadone as their primary opioid analgesic through the Northern Alberta Children's Cancer Program from January 2000 to June 2007 were included. Children who received combination opioid therapy were excluded.

RESULTS

Rotation to methadone was usually by a complete switch from primary opioid. Conversion ratios of morphine equivalent daily dose (MEDD)/methadone daily dose (TMDD) ranged widely from 1:2 in one patient with sudden pain crisis just prior to death, to 60:1 in a patient who had been treated with opioids for months. Methadone was used for a total of 925 patient-days. There were no significant adverse events in any patient, and all but one patient remained on methadone until the time of their death. Clinically, the effectiveness of analgesia clearly improved at time of conversion in 16 patients.

CONCLUSION

With close monitoring, methadone therapy can be done safely in pediatric oncology patient populations in both inpatient and outpatient settings. Our experience suggests improvement in analgesia with the use of methadone, with 16 patients remaining on methadone until they died.