Rates of Fetal Polydrug Exposures in Methadone-Maintained Pregnancies from a High-Risk Population

Methadone maintenance treatment (MMT) is the standard of care during pregnancy for opioid-dependency, showing efficacy in improving prenatal care and reducing risk of relapse. By design, however, MMT is only intended to prevent withdrawal thus facilitating cognitive behavioural interventions. In order to maximize the benefits of MMT, it is essential that methadone is both properly prescribed and that additional addiction treatment is concurrently administered. This study aims to determine the effectiveness of MMT engagement in high-risk pregnant women in reducing polydrug use by objective laboratory examination of neonatal meconium.

Patients and Methods

Over a 29-month period, the Motherisk Laboratory at the Hospital for Sick Children in Toronto analyzed meconium samples as per request by social services and hospitals for drugs of abuse.

Results

Of the 904 meconium samples received, 273 were tested for methadone with 164 positive and 109 negative for methadone. Almost half of the methadone positive samples (46.34%) were also positive for at least one other opioid compound, which did not differ statistically from the methadone-negative control samples (46.79%; Chi square test, p=0.94). No differences were found between the methadone positive and negative groups in rates of concurrent amphetamines, cocaine, cannabis, and alcohol use indicating a similar risk of polydrug use between pregnant women taking or not taking methadone in this population.

Discussion

The high rates of additional opioid and other drug use in the MMT group, suggest that MMT is failing this population of patients. It is possible that methadone doses during pregnancy are not appropriately adjusted for changes in pharmacokinetic parameters (e.g. blood volume, renal function) during the second and third trimesters. This may result in sub-therapeutic dosing creating withdrawal symptoms leading to additional substance use. Alternatively, these results may be demonstrating a substantial lack in delivery of addiction support services in this vulnerable population.     

Effectiveness and cost effectiveness of expanding harm reduction and antiretroviral therapy in a mixed HIV epidemic: a modeling analysis for Ukraine

Background

Injection drug use (IDU) and heterosexual virus transmission both contribute to the growing mixed HIV epidemics in Eastern Europe and Central Asia. In Ukraine—chosen in this study as a representative country—IDU-related risk behaviors cause half of new infections, but few injection drug users (IDUs) receive methadone substitution therapy. Only 10% of eligible individuals receive antiretroviral therapy (ART). The appropriate resource allocation between these programs has not been studied. We estimated the effectiveness and cost-effectiveness of strategies for expanding methadone substitution therapy programs and ART in mixed HIV epidemics, using Ukraine as a case study.

Methods and Findings

We developed a dynamic compartmental model of the HIV epidemic in a population of non-IDUs, IDUs using opiates, and IDUs on methadone substitution therapy, stratified by HIV status, and populated it with data from the Ukraine. We considered interventions expanding methadone substitution therapy, increasing access to ART, or both. We measured health care costs, quality-adjusted life years (QALYs), HIV prevalence, infections averted, and incremental cost-effectiveness. Without incremental interventions, HIV prevalence reached 67.2% (IDUs) and 0.88% (non-IDUs) after 20 years. Offering methadone substitution therapy to 25% of IDUs reduced prevalence most effectively (to 53.1% IDUs, 0.80% non-IDUs), and was most cost-effective, averting 4,700 infections and adding 76,000 QALYs compared with no intervention at US$530/QALY gained. Expanding both ART (80% coverage of those eligible for ART according to WHO criteria) and methadone substitution therapy (25% coverage) was the next most cost-effective strategy, adding 105,000 QALYs at US$1,120/QALY gained versus the methadone substitution therapy-only strategy and averting 8,300 infections versus no intervention. Expanding only ART (80% coverage) added 38,000 QALYs at US$2,240/QALY gained versus the methadone substitution therapy-only strategy, and averted 4,080 infections versus no intervention. Offering ART to 80% of non-IDUs eligible for treatment by WHO criteria, but only 10% of IDUs, averted only 1,800 infections versus no intervention and was not cost effective.

Conclusions

Methadone substitution therapy is a highly cost-effective option for the growing mixed HIV epidemic in Ukraine. A strategy that expands both methadone substitution therapy and ART to high levels is the most effective intervention, and is very cost effective by WHO criteria. When expanding ART, access to methadone substitution therapy provides additional benefit in infections averted. Our findings are potentially relevant to other settings with mixed HIV epidemics. Please see later in the article for the Editors'' Summary     

Thiopropazate Hydrochloride in Persistent Dyskinesia

Thiopropazate (Dartalan) was found to be significantly more effective than a placebo in relieving dyskinesia in 23 patients with functional psychosis and persistent dyskinesia associated with prolonged phenothiazine therapy. Each patient whose dyskinesia had persisted unchanged for at least one month after phenothiazine withdrawal received thiopropazate by mouth for three weeks and the placebo for a similar period. Patients were evaluated before the trial, at three weeks, and at six weeks.The drug also improved psychotic behaviour. Possible side effects, which were generally mild, were noted in eight patients, of whom six had Parkinsonism and four drowsiness. None had side effects while on the placebo.The findings indicate that thiopropazate is of value in persistent dyskinesia associated with prolonged phenothiazine intake—a condition hitherto unresponsive to other treatment. Further research is required to determine the long-term effectiveness of the drug.     

Methadone maintenance in general practice: patients,workload, and outcomes.

OBJECTIVE--To assess recruitment to and work-load associated with methadone maintenance clinics in general practice; to investigate the characteristics of patients and outcomes associated with treatment. DESIGN--Study of case notes. SETTING--Methadone maintenance clinics run jointly by general practitioners and drug counsellors in two practices in Glasgow. PARTICIPANTS--46 injecting drug users receiving methadone maintenance during an 18 month period, 31 of whom were recruited to clinic based methadone maintenance treatment and 15 of whom were already receiving methadone maintenance treatment from the general practitioners. Mean (SD) age of patients entering treatment was 29.6 (5.5) years; 29 were male. They had been injecting opiates for a mean 9.9 (5.1) years, and most had a concurrent history of benzodiazepine misuse. Average reported daily intake of heroin was approximately 0.75 g. Participants in treatment had high levels of preexisting morbidity, and most stated that they committed crime daily. RESULTS--2232 patient weeks of treatment were studied. Mean duration of treatment during the study period was 50.7 (21.1) weeks and retention in treatment at 26 weeks was 83%. No evidence of illicit opiate use was obtained at an average of 78% of patients'' consultations where methadone had been prescribed in the previous week; for opiate injection the corresponding figure was 86%. CONCLUSIONS--Providing methadone maintenance in general practice is feasible. Although costs are considerable, the reduction in drug use, especially of intravenous opiates, is encouraging. Attending clinics also allows this population, in which morbidity is considerable, to receive other health care.     

Failure of acetylmethadol in treatment of narcotic addicts due to nonpharmacologic factors.

Acetylmethadol, a new narcotic substitute, has a longer duration of action than methadone. Seventeen subjects, former heroin users currently under methadone treatment, entered a study of the toxicity and efficacy of this drug. Only nine subjects completed the assessment phase of the study and began the acetylmethadol phase, and only one completed the 8-week study phase. Hence, no conclusions can be drawn about acetylmethadol''s efficacy. The high attrition rate was unrelated to pharmacologic factors; the subjects were concerned that if this drug was effective there would be no methadone to take home and hence no opportunity to trade, sell or "play with" (that is, combine with other drugs) the latter. This study emphasizes the difficulty in determining the efficacy of specific drug treatments for opiate-dependent patients.     

Reduced dosing and liability in methadone maintenance treatment by targeting oestrogen signal for morphine addiction

Methadone maintenance treatment (MMT) is the major tapering therapy for morphine addictive patients. There have gender differences reported in response to MMT. This study discovered that the estrogen‐response element single nucleotide polymorphism (ERE‐SNP; rs16974799, C/T) of cytochrome 2B6 gene (cyp2b6; methadone catabolic enzyme) responded differently to MMT dosing. Oestradiol was associated with high MMT dosing, high enantiomer (R‐ or S‐) of 2‐ethylidene‐1,5‐dimethyl‐3,3‐dipheny‐pyrrolidine (EDDP; methadone metabolite) to methadone ratio and increased drug‐seeking behaviour, implicating oestradiol‐CYP‐EDDP/methadone axis decreasing MMT efficacy. In mouse model, oestrogen mitigates methadone antinociceptive response, facilitates methadone catabolism and up‐regulates methadone‐associated metabolizing enzymes. Oestrogen also ablates chronic methadone administration‐induced rewarding response. Mechanism dissection revealed the CC genotype of CYP2B6‐ERE‐SNP exerts higher ERE sequence alignment score, higher estrogenic response as compared to TT genotype. At last, preclinical study via targeting estrogen signal that tamoxifen (TMX; selective estrogen receptor modulator, SERM) could facilitate the tolerance phase rewarding response of methadone. Strikingly, TMX also reduces tapering/abstinence phases methadone liability in mice. In conclusion, this study demonstrates altering methadone metabolism through targeting estrogen signals might be able to free morphine addictive patients from the addiction of opioid replacement therapy. Therefore, the add‐on therapy clinical trial introducing SERM in MMT regimen is suggested.     

The effect of methadone addiction on cyclic nucleotide levels in regions of rat brain

Studies of tissue culture cells and tissue slices have implicated the nucleotides, cyclic AMP and cyclic GMP, in the mechanism of action of opiates. However, there are little in vivo data to corroborate this hypothesis. We addicted rats to the synthetic opiate, methadone, by providing the drug in their drinking water (dosage 2.1 mg./kg./day). The two cyclic nucleotides were measured in four brain areas which contain a high concentration of opiate receptors: amygdala, neostriatum, periventricular grey, and thalamus. Data were obtained after acute exposure of the drug (1 day), tolerance (35 days), withdrawal (35 days on drug then 1 day off drug), and readjustment (35 days on drug then 21 days off drug). Cyclic GMP levels were low (0.03 pmol./mg. tissue) in the four regions and did not differ significantly during the experiment. Cyclic AMP levels were higher (1-3 pmol./mg.) and fluctuated consistently in the four regions. After acute methadone treatment, there was a reduction in cyclic AMP, which continued at lower levels after tolerance. One day of withdrawal led to increased cAMP, which rose to near control levels. After readjustment, the levels were reduced. These data indicate an involvement of cyclic AMP in the addiction and withdrawal processes in the intact animal.     

Regulation of G Protein-Coupled Receptor Kinase 2 in Brains of Opiate-Treated Rats and Human Opiate Addicts

Abstract: The effects of opiate drugs (heroin, morphine, and methadone) on the levels of G protein-coupled receptor kinase 2 (GRK2) were studied in rat and human brain frontal cortices. The density of brain GRK2 was measured by immunoblot assays in acute and chronic opiate-treated rats as well as in opiate-dependent rats after spontaneous or naloxone-precipitated withdrawal and in human opiate addicts who had died of an opiate overdose. In postmortem brains from human addicts, total GRK2 immunoreactivity was not changed significantly, but the level of the membrane-associated kinase was modestly but significantly increased (12%) compared with matched controls. In rats treated chronically with morphine or methadone modest increases of the enzyme levels (only significant after methadone) were observed. Acute treatments with morphine and methadone induced dose- and time-dependent increases (8–22%) in total GRK2 concentrations [higher increases were observed for the membrane-associated enzyme (46%)]. Spontaneous and naloxone-precipitated withdrawal after chronic morphine or methadone induced a marked up-regulation in the levels of total GRK2 in the rat frontal cortex (18–25%). These results suggest that GRK2 is involved in the short-term regulation of μ-opioid receptors in vivo and that the activity of this regulatory kinase in brain could have a relevant role in opiate tolerance, dependence, and withdrawal.     

Presumptive Treatment of Malaria from Formal and Informal Drug Vendors in Nigeria

Background

Despite policies that recommend parasitological testing before treatment for malaria, presumptive treatment remains widespread in Nigeria. The majority of Nigerians obtain antimalarial drugs from two types of for-profit drug vendors—formal and informal medicine shops—but little is known about the quality of malaria care services provided at these shops.

Aims

This study seeks to (1) describe the profile of patients who seek treatment at different types of drug outlets, (2) document the types of drugs purchased for treating malaria, (3) assess which patients are purchasing recommended drugs, and (4) estimate the extent of malaria over-treatment.

Methods

In urban, peri-urban, and rural areas in Oyo State, customers exiting proprietary and patent medicine vendor (PPMV) shops or pharmacies having purchased anti-malarial drugs were surveyed and tested with malaria rapid diagnostic test. A follow-up phone survey was conducted four days after to assess self-reported drug administration. Bivariate and multivariate regression analysis was conducted to determine the correlates of patronizing a PPMV versus pharmacy, and the likelihood of purchasing an artemisinin-combination therapy (ACT) drug.

Results

Of the 457participants who sought malaria treatment in 49 enrolled outlets, nearly 92% had diagnosed their condition by themselves, a family member, or a friend. Nearly 60% pharmacy customers purchased an ACT compared to only 29% of PPMV customers, and pharmacy customers paid significantly more on average. Multivariate regression results show that patrons of PPMVs were younger, less wealthy, waited fewer days before seeking care, and were less likely to be diagnosed at a hospital, clinic, or laboratory. Only 3.9% of participants tested positive with a malaria rapid diagnostic test.

Conclusions

Poorer individuals seeking care at PPMVs are more likely to receive inappropriate malaria treatment when compared to those who go to pharmacies. Increasing accessibility to reliable diagnosis should be explored to reduce malaria over-treatment.     

Method for determination of methadone in exhaled breath collected from subjects undergoing methadone maintenance treatment

At present drugs of abuse testing using exhaled breath as specimen is only possible for alcohol. However, we recently discovered that using modern liquid chromatography–mass spectrometry technique amphetamine and methamphetamine is detectable in exhaled breath following intake in drug addicts. We therefore undertook to develop a method for determination of methadone in exhaled breath from patients undergoing methadone maintenance treatment. Exhaled breath was collected from 13 patients after intake of the daily methadone dose. The compounds were trapped by filtering the air through a C18 modified silica surface. After elution of any trapped methadone the extract was analysed by a combined liquid chromatography–tandem mass spectrometry method. Recovery of trapped methadone from the filter surface was 96%, no significant matrix effect was observed, and the quantification using methadone-d3 as an internal standard was accurate (<10% bias) and precise (coefficient of variation 1.6–2.0%). Methadone was indisputably identified by means of the mass spectrometry technique in exhaled breath samples from all 13 patients. Identification was based on monitoring two product ions in selected reaction monitoring mode with correct relative ratio (±20%) and correct retention time. Excretion rates ranged from 0.39 to 78 ng/min. No methadone was detected in 10 control subjects. This finding confirms that breath testing is a new possibility for drugs of abuse testing. Collection of exhaled breath specimen is likely to be more convenient and safe as compared to other matrices presently in use.     

Progression of HIV infection in misusers of injected drugs who stop injecting or follow a programme of maintenance treatment with methadone.

OBJECTIVE--To see whether misusers of injected drugs who stop injecting or switch to a programme of maintenance treatment with methadone have a reduced risk of progression of HIV infection when compared with a group of persistent misusers. DESIGN--Observational cohort study in HIV seropositive subjects with a current or past history of misusing injected drugs. SETTING--HIV outpatient clinic at the University Hospital of Zurich, Switzerland. PATIENTS--297 Current and former parenteral drug misusers (median age 27) with asymptomatic HIV infection. During the observation period 80 subjects adhered to a programme of maintenance treatment with methadone, 124 continued with parenteral drug misuse, and 93 former misusers remained free of illicit drugs. No antiretroviral treatment was given during the study. MAIN OUTCOME MEASURES--Probability of progression of HIV infection from asymptomatic to symptomatic (Centers for Disease Control stage IV) as calculated by life table analysis and compared in the three groups of patients by means of a log rank test, and predictors of disease progression as analysed with a Cox proportional hazards regression model. RESULTS--The 297 patients were followed up for a median of 16 months. The median duration of injecting drug misuse before enrollment was 7.1 years. There were no significant differences among the three groups with respect to CD4+ counts at the beginning of the study (median 0.44 x 10(9)/l). Life table analysis showed a significantly lower probability of progression of HIV disease in both the methadone treated group and former drug misusers than in persistent injecting drug misusers. Multivariate regression analysis showed a relative risk of progression of the disease of 1.78 (95% confidence interval 1.20 to 2.67; p less than 0.01) in persistent injecting drug misusers, 0.48 (0.29 to 0.77; p less than 0.01) in the methadone treated group, and 0.66 (0.41 to 1.06; p = 0.085) in former drug misusers. CONCLUSIONS--Stopping the misuse of injected drugs slows the progression of HIV disease in infected subjects. Drug treatment programmes are effective in secondary prevention of HIV associated morbidity.     

Methadone

Methadone and acetylmethadol, although possessing almost all of morphine''s pharmacological properties, differ from other morphine-like drugs in their longer action, more gradual and less intense withdrawal syndrome, and blockade of euphoric effect of other opiates in addicts. A high percentage of patients maintained on methadone are better able to hold employment or to be otherwise socially productive than when dependent on heroin or morphine.A review of published results and procedures used in methadone maintenance treatment programs for heroin dependence is presented. Former heroin addicts are usually maintained on 80 to 120 mg. (high dose) or 20 to 60 mg. (low dose) oral methadone daily. Some programs are reported to have produced 80% success (patients employed or otherwise socially productive). Selection of patients, availability of allied therapeutic and rehabilitative facilities, strict control of supply, record keeping and periodic evaluation are considered essential.Different criteria (“drug-free” vs. “socially productive”) for judging “success” of treatment of heroin-dependent persons by methadone maintenance and administrative problems in large-scale treatment programs constitute the principal aspects of controversy.     

Creating a new drug service in Edinburgh.

After one year Edinburgh''s Community Drug Problem Service has shown that if psychiatric services offer consultation and regular support for drug users many general practitioners will share the care of such patients and prescribe for them, under contract conditions, whether the key worker is a community psychiatric nurse or a drug worker from a voluntary agency. This seems to apply whether the prescribing is part of a "harm reduction" strategy over a long period or whether it is a short period of methadone substitution treatment. Given the 50% prevalence of HIV infection among drug users in the Edinburgh area and the fact that only half of them have been tested for seropositivity, the health and care of this demanding group of young people with a chaotic lifestyle are better shared among primary care, community based drug workers, and specialist community drugs team than treated exclusively by a centralised hospital drug dependency unit. As the progression to AIDS is predictable in a larger proportion of drug users who are positive for HIV, there is an even greater need for coordinated care between specialists and community agencies in the near future.     

HIV and Hepatitis C Virus Testing Delays at Methadone Clinics in Guangdong Province,China

In China, injection drug use is a major transmission route for HIV and hepatitis C virus (HCV) infection. Timely HIV and HCV testing among drug users is vital to earlier diagnosis, linkage to care, and retention. This study aimed to examine HIV and hepatitis C virus (HCV) testing delays at methadone clinics in Guangdong Province, China, and identify individual-level and clinic-level factors associated with delayed testing. Data from 13,270 individuals at 45 methadone clinics in Guangdong were abstracted from a national web-based surveillance database. A two-level binomial logit model was used to examine the association between individual- and clinic-level factors and delayed HIV and HCV testing, defined as receiving a test seven or more days after initial entry into the methadone system. Among 10,046 patients tested for HIV, 1882 (18.7%) had delayed testing; among 10,404 patients tested for HCV, 1542 (14.8%) had delayed testing. Among delayed testers, the median time to HCV testing was significantly longer than the median time to HIV testing (73 vs. 54 days, p<0.05). In the multivariate analysis, the likelihood of delayed HIV testing was higher among individuals with high school or greater education (adjusted odds ratio [aOR] 1.32, 95% confidence interval [CI] 1.02–1.72) and individuals enrolled at clinics with more patients (aOR 1.41, 95% CI 1.05–1.91, for each increase in 100). The likelihood of delayed HCV testing was higher among women (aOR 1.51, 95% CI 1.11–2.06) and employed individuals (aOR 1.21, 95% CI 1.02–1.43). Delayed testing for HIV and HCV is common among patients at methadone clinics in Guangdong, with many patients experiencing delays of two or more months. Structural interventions are needed to expedite testing once individuals enter the methadone maintenance program.     

Beneficial effects of co-treatment with dextromethorphan on prenatally methadone-exposed offspring

Background

Heroin use among young women of reproductive age has drawn much attention around the world. Although methadone is widely used in maintenance therapy for heroin/morphine addiction, the long-term effects of prenatal exposure to methadone and preventative therapy remain unclear. For revealing this question, female pregnant Sprague–Dawley rats were sub-grouped to receive (1) vehicle, (2) methadone 5 mg/kg at embryonic day 3 (E3) and then 7 mg/kg from E4 to E20, (3) dextromethorphan (DM) 3 mg/kg, and (4) methadone + DM (the rats received methadone followed by DM treatment), subcutaneously, twice a day from E3 to E20. The body weight, natural withdrawal, pain sensitivity, ED50, conditioned place preference and water maze were conducted at different postnatal stages (P1 to P79) of offspring. The quantitative real-time RT-PCR and electrophysiology were also used to measure the gene expression of opioid receptors in the spinal cord and changes of LTP/LTD in the hippocampus, separately.

Results

Prenatal exposure to methadone or DM did not affect survival rate, body weight, water maze and LTP or LTD of offspring. However, prenatal methadone significantly increased the withdrawal symptoms, pain sensitivity, addiction liability and decreased the mRNA expression of pain related opioid receptors. Co-administration of DM with methadone in the maternal rats effectively prevented these abnormalities of offspring induced by methadone.

Conclusions

Our study clearly showed that co-administration of dextromethorphan with methadone in the maternal rats prevented the adverse effects induced by prenatal methadone exposure. It implies that dextromethorphan may have a potential to be used in combination with methadone for maintenance treatment in pregnant heroin-addicted women to prevent the adverse effects induced by methadone on offspring.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-015-0126-2) contains supplementary material, which is available to authorized users.     

Prevalence of HIV,Hepatitis B and C Infections and an Assessment of HCV-Genotypes and Two IL28B SNPs among People Who Inject Drugs in Three Regions of Nepal

As part of a comprehensive health care programme for people who use drugs in Nepal, HIV and viral hepatitis B and C status—including risk factors, HCV-genotypes and co-infections—as well as two IL28B Single-nucleotide polymorphisms (SNPs) were assessed for a random sample of 401 people who inject drugs in three regions of Nepal: mid-western Terrai (Nepalgunj), the eastern region (Dharan, Biratnagar) and the central region (Kathmandu, Lalitpur and Chitwan). Individuals were included who showed at least a minimum of health care seeking behaviour. This latter criterion was defined by being registered with any organisation offering health services. The average age of the participants was 30.5 yrs, and the average length of intravenous drug use was 8.5 yrs. The prevalence rates of HBsAg, anti-HIV antibodies and HCV-RNA were 3.5%, 13.8% and 41.9%, respectively. Spontaneous HCV clearance was evident in 16% of all of those who tested positive for anti-HCV antibodies. Independent risk factors for HCV-RNA positivity were age, gender, geographical region, duration of injecting drug use, history of imprisonment and HIV co-infection. In the age group ≤24 yrs, the rate of spontaneous HCV clearance was 43.5%. Overall, 59.8% of HCV infections were caused by HCV genotype 3 and 40.2% by HCV genotype 1. No other HCV genotypes were identified in this study. The IL28B SNP rs12979860 and rs8099917 were identified in 122 patients, and 75.4% of all participants had both favourable genotypes rs12979860 C/C and rs8099917 T/T.     

Chronic Hepatitis Associated with Drug Abuse: Significance of Hepatitis B Virus

One hundred and seventy-seven former heroin addicts, consisting of 85 who were newly admitted to a methadone maintenance program and 92 who had received methadone for a mean period of 30 months, were prospectively studied for up to 2 years in order to determine: (1) the effect of heroin withdrawal on the hepatic abnormalities, and (2) the incidence of HBsAg, anti-HBs, and anti-HCc as indices of the frequency of hepatitis B virus infection. Our study indicates that (1) hepatic abnormalities persist when heroin is discontinued and are not temporally related to drug and/or needle usage, and (2) that 71% of subjects had either HBsAg or anti-HBs; anti-HBc was tested for in 16 patients and was present in 100%, although 9 of the 16 were both HBsAg- and anti-HBs-negative. This study suggests that hepatitis B is largely responsible for the liver dysfunction. It is proposed that an abnormality in immune function, induced by heroin, is responsible for the high incidence of chronic hepatitis. Attention is drawn to the similarity between former drug addicts and hemophiliacs, since both develop chronic hepatitis in spite of anti-HBs in the serum.     

Methadone induced physical dependence in the rat

Although the morphine withdrawal syndrome has been well described in the rat, a syndrome having similar characteristics has not been demonstrated following chronic methadone treatment. In this study we describe the behavioral effects produced by naloxone (4 mg/kg sc) following 72 hours of continuous iv infusion of methadone, (12.2 ug/kg/min), morphine (12.2 to 97.9 ug/kg/min) or saline. The cessation of methadone or morphine but not saline treatment followed by naloxone resulted in graded signs including wet dog shakes, escape attempts, self-stimulation and body weight loss and quantal signs including diarrhea, ear blanching, exophthalmos, ptosis, tachypnea and teeth chattering. These results indicate that this mode of methadone administration produces physical dependence characterized by a morphine-like withdrawal syndrome in the rat.     

Stereospecific gas chromatographic method for determination of methadone in serum.

rac-Methadone is used clinically for the chronic maintenance treatment of heroin addiction and for the relief of pain. As the pharmacological activity of methadone is due primarily to the (-)-(R)-enantiomer, stereospecific measurements of methadone serum concentrations in methadone-treated patients are expected to be more relevant for clinical studies than earlier described total drug measurements. This study describes a stereospecific gas chromatographic (GC) method for the determination of methadone in serum. The extracted methadone was derivatizised with (-)-menthyl chloroformate. The diastereometric derivatives were analysed by GC on a capillary column and detected with a nitrogen-phosphorus detector. The resolution factor obtained for the methadone enantiomers was 1.1 with a relatively short time of analysis (30 min). By analysing the pure (-)-(R)-enantiomer, no racemization was seen during the analysis. The lower limit of quantitation was 75 nmol/l for each enantiomer. Measurements of the ratio between (-)-(R)- and (+)-(S)-methadone concentrations in serum from five methadone-treated patients showed interindividual differences (range 0.5-1.1). The patient results correlated well with those from another GC method measuring total methadone.     

Patient Satisfaction with Methadone Maintenance Treatment in Vietnam: A Comparison of Different Integrative-Service Delivery Models

Background

Patient satisfaction is an important component of quality in healthcare delivery. To inform the expansion of Methadone Maintenance Treatment (MMT) services in Vietnam, we examined the satisfaction of patients with regards to different services delivery models and identified its associated factors.

Methods

We interviewed 1,016 MMT patients at 5 clinics in Hanoi and Nam Dinh province. The modified SATIS instrument, a 10-item scale, was used to measure three dimensions: “Services quality and convenience”, “Health workers’ capacity and responsiveness” and “Inter-professional care”.

Results

The average score was high across three SATIS dimensions. However, only one third of patients completely satisfied with general health services and treatment outcomes. Older age, higher education, having any problem in self-care and anxiety/depression were negatively associated with patient’s satisfaction. Meanwhile, patients receiving MMT at clinics, where more comprehensive HIV and general health care services were available, were more likely to report a complete satisfaction.

Conclusion

Patients were highly satisfied with MMT services in Vietnam. However, treatment for drug users should go beyond methadone maintenance to address complicated health demands of drug users. Integrating MMT with comprehensive HIV and general health services together with improving the capacity of health workers and efficiency of services organisation to provide interconnected health care for drug users are critical for improving the outcomes of the MMT program.