Electrocardiographic abnormalities during recovery from ultra-short opiate detoxification

Drug-drug interactions in the treatment for alcohol use disorders: A comprehensive review

Drug interactions are one of the most common causes of side effects in polypharmacy. Alcoholics are a category of patients at high risk of pharmacological interactions, due to the presence of comorbidities, the concomitant intake of several medications and the pharmacokinetic and pharmacodynamic interferences of ethanol. However, the data available on this issue are limited. These reasons often frighten clinicians when prescribing appropriate pharmacological therapies for alcohol use disorder (AUD), where less than 15% of patients receive an appropriate treatment in the most severe forms. The data available in literature regarding the relevant drug-drug interactions of the medications currently approved in United States and in some European countries for the treatment of AUD (benzodiazepines, acamprosate, baclofen, disulfiram, nalmefene, naltrexone and sodium oxybate) are reviewed here. The class of benzodiazepines and disulfiram are involved in numerous pharmacological interactions, while they are not conspicuous for acamprosate. The other drugs are relatively safe for pharmacological interactions, excluding the opioid withdrawal syndrome caused by the combination of nalmefene or naltrexone with an opiate medication. The information obtained is designed to help clinicians in understanding and managing the pharmacological interactions in AUDs, especially in patients under multi-drug treatment, in order to reduce the risk of a negative interaction and to improve the treatment outcomes.

Differentiating the Effect of an Opioid Agonist on Cardiac Repolarization From µ-Receptor-mediated, Indirect Effects on the QT Interval: A Randomized, 3-way Crossover Study in Healthy Subjects

PURPOSE

A thorough QT study was conducted in healthy subjects to evaluate the effect of buprenorphine hydrochloride administered through a buccal soluble film under coverage of naltrexone to block confounding, secondary QT effects.

METHODS

Healthy subjects were enrolled in a randomized, partially blinded, 4-way crossover designed study. Subjects received buprenorphine 3 mg with naltrexone, naltrexone alone (with placebo films), placebo (placebo films and placebo naltrexone), and open-label moxifloxacin 400 mg with placebo naltrexone in separate in-house treatment periods. Naltrexone treatment (50 mg) was initiated 12 hours before buprenorphine and was given every 12 hours for a total of 4 doses. ECG data were extracted from a continuous recording predose and serially after dosing on the treatment day. ECG intervals were measured at a central ECG laboratory by using the high-precision QT technique. The QT interval was corrected for heart rate with Fridericia's formula (QTcF), and change-from-predose baseline QTcF (∆QTcF) was analyzed by using a mixed effect model.

FINDINGS

Fifty-eight subjects (35 males) with a mean age of 32 were enrolled into the study. Treatment with buprenorphine 3 mg resulted in a small QT effect with the largest mean naltrexone-corrected ∆QTcF reaching 5.8 msec at 8 hours' postdosing (upper bound of the 90% CI below 10 msec). Exposure response analysis with a linear model demonstrated a significant linear relationship between plasma levels and naltrexone-corrected ∆QTcF, with an estimated mean slope of 0.65 msec per nanogram/milliliter (90% CI, 0.22 to 1.08). Using the exposure response model, an effect on ∆QTcF of 4.5 msec (2.80 to 6.12) can be predicted at the observed geometric peak plasma level after administration of the 3-mg buprenorphine dose in this study (3.6 ng/mL [3.33 to 3.98]). Naltrexone alone did not have a relevant effect on the QTcF interval.

IMPLICATIONS

The present study showed that buprenorphine plasma levels up to 5 ng/mL had no effect on the QTc above the level of clinical concern.

Opioid antagonists under heavy sedation or anaesthesia for opioid withdrawal

BACKGROUND

Withdrawal (detoxification) is necessary prior to drug-free treatment or as the end point of long-term substitution treatment.

OBJECTIVES

To assess the effectiveness of opioid antagonists to induce opioid withdrawal with concomitant heavy sedation or anaesthesia, in terms of withdrawal signs and symptoms, completion of treatment and adverse effects.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2009), Medline (January 1966 to 11 August 2009), Embase (January 1985 to 2009 Week 32), PsycINFO (1967 to July 2009), and reference lists of articles.

SELECTION CRITERIA

Controlled studies of antagonist-induced withdrawal under heavy sedation or anaesthesia in opioid-dependent participants compared with other approaches, or a different regime of anaesthesia-based antagonist-induced withdrawal.

DATA COLLECTION AND ANALYSIS

One reviewer assessed studies for inclusion, undertook data extraction and assessed quality. Inclusion decisions and the overall process were confirmed by consultation between all authors.

MAIN RESULTS

Nine studies (eight randomised controlled trials) involving 1109 participants met the inclusion criteria for the review.Antagonist-induced withdrawal is more intense but less prolonged than withdrawal managed with reducing doses of methadone, and doses of naltrexone sufficient for blockade of opioid effects can be established significantly more quickly with antagonist-induced withdrawal than withdrawal managed with clonidine and symptomatic medications. The level of sedation does not affect the intensity and duration of withdrawal, although the duration of anaesthesia may influence withdrawal severity. There is a significantly greater risk of adverse events with heavy, compared to light, sedation (RR 3.21, 95% CI 1.13 to 9.12, P = 0.03) and probably with this approach compared to other forms of detoxification.

AUTHORS' CONCLUSIONS

Heavy sedation compared to light sedation does not confer additional benefits in terms of less severe withdrawal or increased rates of commencement on naltrexone maintenance treatment. Given that the adverse events are potentially life-threatening, the value of antagonist-induced withdrawal under heavy sedation or anaesthesia is not supported. The high cost of anaesthesia-based approaches, both in monetary terms and use of scarce intensive care resources, suggest that this form of treatment should not be pursued.

Opioid antagonists under heavy sedation or anaesthesia for opioid withdrawal

BACKGROUND

Withdrawal (detoxification) is necessary prior to drug-free treatment. It may also represent the end point of long-term opioid replacement treatment such as methadone maintenance. The availability of managed withdrawal is essential to an effective treatment system.

OBJECTIVES

To assess the effectiveness of interventions involving the administration of opioid antagonists to induce opioid withdrawal with concomitant heavy sedation or anaesthesia, in terms of withdrawal signs and symptoms, completion of treatment and adverse effects.

SEARCH STRATEGY

We searched the Drugs and Alcohol Group register (October 2003), Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2004), Medline (January 1966 to January 2005), Embase (January 1985 to January 2005), PsycINFO (1967 to January 2005), and Cinahl (1982 to December 2004) and reference lists of studies.

SELECTION CRITERIA

Controlled trials comparing antagonist-induced withdrawal under heavy sedation or anaesthesia with another form of treatment, or a different regime of anaesthesia-based antagonist-induced withdrawal.

DATA COLLECTION AND ANALYSIS

One reviewer assessed studies for inclusion and undertook data extraction and assessed quality. Inclusion decisions and the overall process were confirmed by consultation between all three reviewers.

MAIN RESULTS

Six studies (five randomised controlled trials) involving 834 participants met the inclusion criteria for the review.Antagonist-induced withdrawal is more intense but less prolonged than withdrawal managed with reducing doses of methadone, and doses of naltrexone sufficient for blockade of opioid effects can be established significantly more quickly with antagonist-induced withdrawal than withdrawal managed with clonidine and symptomatic medications. The level of sedation does not affect the intensity and duration of withdrawal, although the duration of anaesthesia may influence withdrawal severity. There is a significantly greater risk of adverse events with heavy, compared to light, sedation (RR 3.21, 95% CI 1.13 to 9.12, P = 0.03) and probably also other forms of detoxification.

AUTHORS' CONCLUSIONS

Heavy sedation compared to light sedation does not confer additional benefits in terms of less severe withdrawal or increased rates of commencement on naltrexone maintenance treatment. Given that the adverse events are potentially life-threatening, the value of antagonist-induced withdrawal under heavy sedation or anaesthesia is not supported. The high cost of anaesthesia-based approaches, both in monetary terms and use of scarce intensive care resources, suggest that this form of treatment should not be pursued.

Antagonist-precipitated heroin withdrawal under anaesthetic prior to maintenance naltrexone treatment: determinants of withdrawal severity

This study sought to characterize antagonist-precipitated heroin withdrawal during and immediately following anaesthesia and to identify the determinants of withdrawal severity and duration in 48 dependent heroin users. Objective withdrawal signs decreased significantly with each naloxone bolus administered under anaesthetic. The cost (amount) of the final heroin administration and the number of hours between last heroin use and commencement of anaesthesia were significant, independent predictors of the severity of withdrawal symptomatology. While 83% (40/48) of participants completed withdrawal according to objective criteria and commenced maintenance naltrexone treatment, almost half (22/48) were unable to commence naltrexone on the day of the procedure due to residual withdrawal signs. Fourteen of these 22 participants subsequently commenced naltrexone (median number of days between admission and commencement of naltrexone was 2, range 1 - 6) while eight left treatment prior to initiation of naltrexone. Significantly fewer of those with more severe withdrawal signs during anaesthesia commenced naltrexone (40% vs. 60%). While the severity and duration of withdrawal symptomatology may be moderated by encouraging participants to reduce (or cease) heroin use close to the time of withdrawal, for a substantial proportion of participants in this study, heroin withdrawal by this antagonist-precipitated procedure was neither rapid nor painless. [Ali R, Thomas P, White J, McGregor C, Danz,C, Gowing L, Stegink A, Athanasos P. Antagonist-precipitated heroin withdrawal under anaesthetic prior to maintenance naltrexone treatment: determinants of withdrawal severity.

A comparison of antagonist-precipitated withdrawal under anesthesia to standard inpatient withdrawal as a precursor to maintenance naltrexone treatment in heroin users: outcomes at 6 and 12 months

To compare two methods of heroin withdrawal, 51 heroin users were randomised to undergo a 1 day precipitated withdrawal procedure using naloxone under anaesthetic. About 50 participants were randomised to receive the current standard inpatient withdrawal treatment using clonidine plus symptomatic medication. Following withdrawal, both groups were offered 9 months of naltrexone treatment and supportive counselling. Outcome measures were: commencement of naltrexone, retention in treatment and heroin use at 6 and 12 months. Significantly more of the precipitated withdrawal group completed withdrawal, commenced naltrexone and stayed in treatment for the first 3 months. Overall, there was a significant reduction in both self-reported heroin use and morphine concentration in hair over the 12 month study period, with participants in the precipitated withdrawal group showing significantly lower morphine concentration at 6 months. Being younger and having a lower level of dependence were predictors of abstinence at 6 and 12 months. The advantage of precipitated withdrawal under anesthesia did not persist beyond 3 months with respect to retention in naltrexone treatment or beyond 6 months with respect to heroin use. Long-term follow-up is crucial in assessing the effects of treatment interventions for heroin dependence.

Opioid antagonists under heavy sedation or anaesthesia for opioid withdrawal

BACKGROUND

Withdrawal (detoxification) is necessary prior to drug-free treatment. It may also represent the end point of long-term opioid replacement treatment such as methadone maintenance. The availability of managed withdrawal is essential to an effective treatment system.

OBJECTIVES

To assess the effectiveness of interventions involving the administration of opioid antagonists to induce opioid withdrawal with concomitant heavy sedation or anaesthesia.

SEARCH STRATEGY

Multiple electronic databases (including MEDLINE, EMBASE, PsycLIT, Australian Medical Index, Cochrane Controlled Trials Register, and CINAHL) were systematically searched. Reference lists of retrieved studies, reviews and conference abstracts were handsearched.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared the administration of opioid antagonists under heavy sedation or anaesthesia with another form of treatment.

DATA COLLECTION AND ANALYSIS

One reviewer assessed studies for inclusion and undertook data extraction. Inclusion decisions and the overall process were confirmed by consultation between all three reviewers.

MAIN RESULTS

As yet, no studies have been published comparing treatment regimes involving the administration of opioid antagonists under heavy sedation or anaesthesia with other approaches to detoxification. Treatment regimes for the studies considered for this review varied in the opioid antagonist used, the dose and mode of administration, the anaesthetic agent, duration of anaesthesia and adjunct medications employed. More detailed monitoring of withdrawal is required before any conclusions can be drawn as to what comprises a typical pattern of withdrawal and what factors might influence the pattern. There is only very limited information on referral to ongoing treatment, and relapse to opioid use. Together with the lack of adequate comparisons, this makes it impossible to draw any conclusions about the long-term effectiveness, or the cost-effectiveness, of withdrawal induced by opioid antagonists under heavy sedation or anaesthesia.

REVIEWER'S CONCLUSIONS

Considerably more research evidence will be needed before any conclusions can be drawn regarding the effectiveness of managing withdrawal by administration of opioid antagonists under heavy sedation or anaesthesia. The risk of vomiting during sedation, respiratory depression and cardiac irregularities point to the approach being limited to facilities equipped for intubation, assisted ventilation and a high level of monitoring, and with the capacity to respond to adverse events that might occur. The approach must be regarded as experimental with both risks and benefits remaining uncertain.

Endogenous opiates: 1999

This paper is the twenty-second installment of the annual review of research concerning the opiate system. It summarizes papers published during 1999 that studied the behavioral effects of the opiate peptides and antagonists, excluding the purely analgesic effects, although stress-induced analgesia is included. The specific topics covered this year include stress; tolerance and dependence; learning, memory, and reward; eating and drinking; alcohol and other drugs of abuse; sexual activity, pregnancy, and development; mental illness and mood; seizures and other neurologic disorders; electrical-related activity; general activity and locomotion; gastrointestinal, renal, and hepatic function; cardiovascular responses; respiration and thermoregulation; and immunologic responses.