Preliminary results of guanfacine treatment of acute opiate withdrawal

Methadone at tapered doses for the management of opioid withdrawal

BACKGROUND

The evidence of tapered methadone's efficacy in managing opioid withdrawal has been systematically evaluated in the previous version of this review that needs to be updated

OBJECTIVES

To evaluate the effectiveness of tapered methadone compared with other detoxification treatments and placebo in managing opioid withdrawal on completion of detoxification and relapse rate.

SEARCH METHODS

We searched: Cochrane Central Register of Controlled Trials (The Cochrane Library 2012, Issue 4), PubMed (January 1966 to May 2012), EMBASE (January 1988 to May 2012), CINAHL (2003- December 2007), PsycINFO (January 1985 to December 2004), reference lists of articles.

SELECTION CRITERIA

All randomised controlled trials that focused on the use of tapered methadone versus all other pharmacological detoxification treatments or placebo for the treatment of opiate withdrawal.

DATA COLLECTION AND ANALYSIS

Two review authors assessed the included studies. Any doubts about how to rate the studies were resolved by discussion with a third review author. Study quality was assessed according to the criteria indicated in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Twenty-three trials involving 2467 people were included. Comparing methadone versus any other pharmacological treatment, we observed no clinical difference between the two treatments in terms of completion of treatment, 16 studies 1381 participants, risk ratio (RR) 1.08 (95% confidence interval (CI) 0.97 to 1.21); number of participants abstinent at follow-up, three studies, 386 participants RR 0.98 (95% CI 0.70 to 1.37); degree of discomfort for withdrawal symptoms and adverse events, although it was impossible to pool data for the last two outcomes. These results were confirmed also when we considered the single comparisons: methadone with: adrenergic agonists (11 studies), other opioid agonists (eight studies), anxiolytic (two studies), paiduyangsheng (one study). Comparing methadone with placebo (two studies) more severe withdrawal and more drop-outs were found in the placebo group. The results indicate that the medications used in the included studies are similar in terms of overall effectiveness, although symptoms experienced by participants differed according to the medication used and the program adopted.

AUTHORS' CONCLUSIONS

Data from literature are hardly comparable; programs vary widely with regard to the assessment of outcome measures, impairing the application of meta-analysis. The studies included in this review confirm that slow tapering with temporary substitution of long- acting opioids, can reduce withdrawal severity. Nevertheless, the majority of patients relapsed to heroin use.

Methadone at tapered doses for the management of opioid withdrawal

BACKGROUND

Despite widespread use in many countries the evidence of tapered methadone's efficacy in managing opioid withdrawal has not been systematically evaluated.

OBJECTIVES

To evaluate the effectiveness of tapered methadone compared with other detoxification treatments and placebo in managing opioid withdrawal on completion of detoxification and relapse rate.

SEARCH STRATEGY

We searched: Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005), MEDLINE (January 1966 to December 2004), EMBASE (January 1988 to December 2004), PsycINFO (January 1985 to December 2004), and reference lists of articles. We also contacted manufacturers and researchers in the field.

SELECTION CRITERIA

All randomised controlled trials which focus on the use of tapered methadone versus all other pharmacological detoxification treatments or placebo for the treatment of opiate withdrawal.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed the included studies. Any doubt about how to rate the studies were resolved by discussion with a third reviewer. Study quality was assessed according to the criteria indicated in Cochrane Reviews Handbook 4.2. (Alderson 2004)

MAIN RESULTS

Sixteen trials involving 1187 people were included. Comparing methadone versus any other pharmacological treatment we observed no clinical difference between the two treatments in terms of completion of treatment, relative risk (RR) 1.12; 95% CI 0.94 to 1.34 and results at follow-up RR 1.17; 95% CI 0.72 to 1.92. It was impossible to pool data for the other outcomes but the results of the studies did not show significant differences between the considered treatments. These results were confirmed also when we considered the single comparisons: methadone with: adrenergic agonists (11 studies), other opioid agonists (four studies), chlordiazepoxide (study). Comparing methadone with placebo (one study) more severe withdrawal and more drop outs were found in the placebo group. The results indicate that the medications used in the included studies are similar in terms of overall effectiveness, although symptoms experienced by participants differed according to the medication used and the program adopted.

AUTHORS' CONCLUSIONS

Data from literature are hardly comparable; programs vary widely with regard to duration, design and treatment objectives, impairing the application of meta-analysis. The studies included in this review confirm that slow tapering with temporary substitution of long acting opioids, accompanied by medical supervision and ancillary medications can reduce withdrawal severity. Nevertheless the majority of patients relapsed to heroin use.

Nimodipine in opiate detoxification: a controlled trial

OBJECTIVE

To evaluate the use of L-type calcium channel blockers (CaCB) in out-patient opiate detoxification.

DESIGN

Controlled trial with sequential allocation of patients to groups.

METHODS

Three groups of individuals subject to opiate detoxification were involved: (1) the experimental group (n=30) received a course of nimodipine and dextropropoxiphen; (2) one control group (n=20) was detoxified with a course of dextropropoxiphen and benzodiazepine; and (3) a second control group (n=30) was treated with a standard course of alpha-2-adrenergic agents and naltrexone. In all cases, the detoxification course was scheduled to last 7 days.

RESULTS

All the groups showed a significant opiate withdrawal syndrome (OWS) during detoxification (follow-up effect: Lambda=0.04; F6.52=201.89; P < 0.001), but from the first day the group treated with CaCB manifested fewer symptoms than the control groups (treatment effect: F2.57=97.99; P < 0.001). From the start, the intensity of the OWS was reduced by half in the CaCB group (M=6.67) compared with that manifested by the two other groups (M approximately 13). The clinical impression of the evolution of the detoxification was that it was comfortable and free of complications (significant side-effects were not observed).

CONCLUSIONS

The results of the study suggest that the use of calcium channel blockers (CaCB) may be an effective method in opiate detoxification. Full randomized trials are warranted.

Neurobiological adaptations to psychostimulants and opiates as a basis of treatment development

Abuse of illicit substances, in particular psychostimulants and opiates, is a worldwide public health issue. Chronic use of cocaine and amphetamine causes common neurobiological adaptations that may guide new treatment development. These include perturbations in dopamine and serotonin neurotransmission, leading to trials of antidepressants, and serotonin and dopamine augmentation strategies. The detection of cerebral perfusion abnormalities caused by psychostimulants has led to examination of antiplatelet and excitatory amino acid (EAA) antagonist therapies. Further, development of cocaine vaccines allows for testing of peripheral blockade approaches to cocaine addiction. New approaches to behavioral treatments for cocaine dependence are also reviewed. For opiate dependence, understanding of heroin's effects on mu and kappa opiate receptors has led to investigations of the partial mu agonist buprenorphine in opiate maintenance. Evidence for hyper-excitability of locus coeruleus (LC) noradrenergic neurons and EEA inputs to the LC guides trials of new alpha 2-adrenergic agonists and EEA antagonists to alleviate opiate withdrawal. Finally, clinical experience with withdrawal from methadone and LAAM has led to trials of antagonist-accelerated opiate withdrawal. Improved treatment of psychostimulant and opiate addiction is critically needed, and likely to have wide-reaching impact in health care and society.

Combined use of trazodone-naltrexone versus clonidine-naltrexone in rapid withdrawal from methadone treatment. A comparative inpatient study

Trazodone is a non-tricyclic antidepressant drug with specific antagonistic activities at 5-HT(2) and alpha-1 adrenoceptors. We test the efficacy of trazodone (T) compared with clonidine (C) in rapid opiate detoxification (ROD) from methadone after reduction to a daily maintenance dose </=20 mg. Forty five inpatients were consecutively assigned either to T (n=30) or to C (n=15) treatment in a 7-day ROD protocol with naltrexone administration starting at day 4. The maximum daily dosage was 800 mg for T and 1.2 mg for C. The retention rate was similar in both groups (93.3%). Overall, T was as effective as C in the ROD protocol. T was slightly superior in controlling some subjective and psychological symptoms, but not under naltexone challenge. No severe adverse effects were observed. We conclude that T is effective, safe and well-tolerated in acute withdrawal from methadone. Further investigation is needed to test the effectiveness and safety of T in ultra-rapid protocols and its usefulness in long-term administration to detoxified addicts.

Ultra-rapid, antagonist-precipitated opiate detoxification under general anaesthesia or sedation

Ultra-rapid opiate withdrawal precipitated by naloxone or naltrexone during general anaesthesia or varying degrees of sedation, usually with the addition of α-2 adrenergic agonists, is an increasingly popular technique. As with anaesthesia or effective analgesia for dentistry or obstetrics, it can be justified on general humane principles. It also simplifies and speeds the transition to treatment programmes involving naltrexone. This paper reviews its development and the current range of techniques, including the use of octreotide to prevent diarrhoea. The prospect of avoiding or shortening the worst discomforts of withdrawal may encourage more opiate addicts to attempt detoxification and opiate-free management, including patients who have been successfully rehabilitated on long-term methadone maintenance treatment (MMT). Despite good motivation and preparation, a significant minority of MMT patients consistently fail to complete conventional withdrawal programmes because of increasing physical discomfort. It is emphasized that there is usually more to the treatment of opiate dependence than withdrawal.

Opiate detoxification of methadone maintenance patients using lefetamine, clonidine and buprenorphine

Thirty-nine methadone maintenance patients were included in a 9-day, double blind, randomized, inpatient detoxification trial. Methadone was tapered to 10 mg/day and then patients were assigned to one of these 3 protocols: clonidine (0.3-0.9 mg/day), lefetamine (60-240 mg/day), buprenorphine (0.15-0.9 mg/day). Buprenorphine treatment was significantly superior to clonidine and to lefetamine (F = 3.96 df = 2, 29 P < 0.05) in controlling objective, subjective and psychological withdrawal symptomatology. Clonidine was more effective than lefetamine in suppressing withdrawal in the first 3 days of treatment (day 3: F = 4.10 df = 2, 30 P < 0.05), and this trend was apparent on the objective and psychological items. In addition to evaluations of the efficacy of the single drugs used, the study showed that tapering methadone to low doses before entering the pharmacologically assisted discontinuation phase was clinically acceptable in detoxification from long-term methadone treatment.

Efficacy of methadone versus methadone and guanfacine in the detoxification of heroin-addicted patients

In a randomized double-blind study, the clinical efficacy of methadone vs. methadone and guanfacine was assessed in terms of evolution of opioid withdrawal symptoms during inpatient detoxification. A total of 144 patients were included and randomly allocated to three different treatment groups: methadone alone, and two combined treatment schedules (methadone plus 3 or 4 mg of guanfacine). No differences were observed among the three groups with regard to retention rate throughout the study period. Both therapies, methadone and methadone plus guanfacine, determined a slight increase in withdrawal scores when methadone was discontinued. However, guanfacine was unable to effectively control methadone-associated withdrawal symptoms. These results indicate that guanfacine does not effectively reduce the opioid withdrawal symptoms.

A 24-h inpatient detoxification treatment for heroin addicts: a preliminary investigation

The present study describes a detoxification method which takes only 4 h to complete. Eleven polydrug users addicted to opiates were detoxified 12 h after their last dose of heroin, in an intensive care unit. The detoxification was carried out using naltrexone, after sedation with midazolan. After detoxification (12 h) patients were discharged without withdrawal symptoms. This procedure offers a rapid detoxification procedure which seems to be widely accepted by the addicts themselves.

Treatment of heroin withdrawal with guanfacine: an open clinical investigation

The alpha 2-adrenoceptor stimulant, guanfacine, was used to treat, under open conditions, heroin addicts who volunteered to withdraw from heroin usage. Thirty-four addicts (29 males, 5 females) aged 17 to 31 years were treated for 5 to 15 days with varying doses of guanfacine (0.03 up to 1.75 mg daily). Efficacy was determined by the "Opiate Withdrawal Checklist" (OWCL), administered several times during the day, and by the Clinical Global Impression (CGI) scale. All symptom categories of the OWCL, except "sleep disturbances" were equally ameliorated by the treatment. According to the CGI, 88% of the cases were judged as having had a very good or good improvement. Tolerability to the medication was judged as good or very good in 94% of the cases.

Yohimbine reduces morphine tolerance in guinea-pig ileum

Opiates are known to inhibit electrically-evoked twitches of longitudinal muscle-myenteric plexus strips from guinea-pig ileum. When this preparation was incubated with morphine for 1 h tolerance developed to the inhibitory effect, since dose-response curves were shifted to the right. In the present study, the effects of alpha-2 adrenergic agents on the tolerance induced by morphine in this preparation was investigated. Addition of yohimbine 10 microM (but not 0.1 or 1 microM) to the incubating medium reduced the magnitude of opiate tolerance. This effect did not appear in the presence of the alpha-2 agonists clonidine or guanfacine (10 microM). Our results provide evidence of the longitudinal muscle-myenteric plexus as a useful model for the study of the relationship between morphine tolerance and alpha-2 adrenergic mechanisms.