Methadone tolerance testing in drug misusers

Forensic pathological study of methadone-related deaths in the Genoa (Italy) district: A six-year study

Methadone is a synthetic opioid, a pure agonist of the μ receptor. It is used for opioid maintenance therapy in heroin addiction. In recent years, Italian studies of incidence and prevalence have indicated an increase in the illegal sales of methadone and, consequently, an increase in deaths due to acute methadone intoxication as well. The present review is a prospective-observational study regarding epidemiological and toxicological analyses of methadone-related deaths recorded in the district of Genoa (Italy) from 2013 to 2018. The study includes a list of twenty-six people that have died from methadone toxicity: twenty-two males and four females. The concentration of methadone in the blood samples ranged from 181 to 4058.53 ng/mL, with an average of 964.29 ng/mL. Six subjects tested positive for methadone alone; twenty cases, however, presented drugs or substances in different concentrations in the blood samples. Illegal sales and consumption of methadone have a negative impact on the self-administration therapy of opioid addiction, inducing patients to increase their dosage or sell methadone in order to purchase illegal drugs. As shown in our study, this behaviour is associated with an increase in methadone-related deaths. Accordingly, careful monitoring of dosage administrated to patients is required in order to render the system safer.

Medications for Alcohol and Opioid Use Disorders and Risk of Suicidal Behavior, Accidental Overdoses, and Crime

OBJECTIVE

The authors examined associations between medications for alcohol and opioid use disorders (acamprosate, naltrexone, methadone, and buprenorphine) and suicidal behavior, accidental overdoses, and crime.

METHOD

In this total population cohort study, 21,281 individuals who received treatment with at least one of the four medications between 2005 and 2013 were identified. Data on medication use and outcomes were collected from Swedish population-based registers. A within-individual design (using stratified Cox proportional hazards regression models) was used to compare rates of suicidal behavior, accidental overdoses, and crime for the same individuals during the period when they were receiving the medication compared with the period when they were not.

RESULTS

No significant associations with any of the primary outcomes were found for acamprosate. For naltrexone, there was a reduction in the hazard ratio for accidental overdoses during periods when individuals received treatment compared with periods when they did not (hazard ratio=0.82, 95% CI=0.70, 0.96). Buprenorphine was associated with reduced arrest rates for all crime categories (i.e., violent, nonviolent, and substance-related) as well as reduction in accidental overdoses (hazard ratio=0.75, 95% CI=0.60, 0.93). For methadone, there were significant reductions in the rate of suicidal behaviors (hazard ratio=0.60, 95% CI=0.40-0.88) as well as reductions in all crime categories. However, there was an increased risk for accidental overdoses among individuals taking methadone (hazard ratio=1.25, 95% CI=1.13, 1.38).

CONCLUSIONS

Medications currently used to treat alcohol and opioid use disorders also appear to reduce suicidality and crime during treatment.

Opioid tolerance in methadone maintenance treatment: comparison of methadone and levomethadone in long-term treatment

Background

This study aimed to investigate the development of opioid tolerance in patients receiving long-term methadone maintenance treatment (MMT).

Methods

A region-wide cross-sectional study was performed focusing on dosage and duration of treatment. Differences between racemic methadone and levomethadone were examined. All 20 psychiatric hospitals and all 110 outpatient clinics in Berlin licensed to offer MMT were approached in order to reach patients under MMT fulfilling the DSM IV criteria of opiate dependence. In the study, 720 patients treated with racemic methadone or levomethadone gave information on the dosage of treatment. Out of these, 679 patients indicated the duration of MMT.

Results

Treatment with racemic methadone was reported for 370 patients (54.5 %), with levomethadone for 309 patients (45.5 %). Mean duration of MMT was 7.5 years. We found a significant correlation between dosage and duration of treatment, both in a conjoint analysis for the two substances racemic methadone and levomethadone and for each substance separately. These effects remained significant when only patients receiving MMT for 1 year or longer were considered, indicating proceeding tolerance development in long-term treatment. When correlations were compared between racemic methadone and levomethadone, no significant difference was found.

Conclusions

Our data show a tolerance development under long-term treatment with both racemic methadone and levomethadone. Tolerance development did not differ significantly between the two substances.

Effects of Dextromethorphan on reducing methadone dosage in opium addicts undergoing methadone maintenance therapy: A double blind randomized clinical trial

BACKGROUND

Dextromethorphan (DM) is an N-methyl-D-aspartate (NMDA) receptor antagonist that may be useful during opiate addiction process, especially in reducing methadone consumption in methadone maintenance therapy (MMT). The goal of the current study was to evaluate the effects of oral administration of DM on reducing methadone dose in MMT used to treat illicit opioid drug abuse.

METHODS

A double-blinded randomized clinical trial was designed. Seventy two opiate abusers undergoing MMT were randomly divided into two groups. Participants in the intervention group were medicated by DM while those in the control group received placebo. After a 6-week follow-up, methadone consumption dosage, quality of life (QOL) and withdrawal symptoms were assessed and compared between the two groups by repeated measure ANOVA statistical test.

RESULTS

The mean of methadone consumption in the DM and control groups were 62.7 mg/day (52.7-72.7) and 70.4 mg/day (60.4-80.4), respectively. No statistically significant difference was found between the two groups among the four evaluations made (F = 1.192, P = 0.279). There were not any significant differences in withdrawal symptoms between the two groups (P > 0.05). Total mean scores of QOL in the intervention and control groups were 84.8 (78.7-90.8) and 77.8 (71.8-83.7) (P > 0.05), respectively.

CONCLUSIONS

Although DM might be useful for opioid dependence treatment, results of the current study did not reveal any statistically significant differences. Therefore, further studies exploring this possibility are needed.