Effects of ketamine on precipitated opiate withdrawal. Anesthesia-assisted vs buprenorphine- or clonidine-assisted heroin detoxification and naltrexone induction: a randomized trial. 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. Efficacy and safety of two new methods of rapid intravenous detoxification in heroin addicts previously treated without success. Acute detoxification of opioid-addicted patients with naloxone during propofol or methohexital anesthesia: a comparison of withdrawal symptoms, neuroendocrine, metabolic, and cardiovascular patterns. Rapid detoxification from opioid dependence under general anaesthesia versus standard methadone tapering: abstinence rates and withdrawal distress experiences. Opioid antagonist detoxification under anaesthesia versus traditional clonidine detoxification combined with an additional week of psychosocial support: a randomised clinical trial.
N-methyl-D-aspartate antagonists were shown to be effective in suppressing the symptoms of opiate withdrawal. Intravenous anesthetic, ketamine, is the most potent N-methyl-D-aspartate antagonist available in clinical practice. The present study was designed to evaluate the effects of subanesthetic ketamine infusion, as little human data are available on ketamine in precipitated opiate withdrawal.
                A total of 58 opiate-dependent patients were enrolled in a randomized, placebo-controlled, double-blind study. Patients underwent rapid opiate antagonist induction under general anesthesia. Prior to opiate antagonist induction patients were given either placebo (normal saline) or subanesthetic ketamine infusion of 0.5 mg/kg/h. Further evaluations were divided into three phases: anesthetic, early postanesthetic (48 hours), and remote at 4 months after procedure. Cardiovascular, respiratory, renal, and gastrointestinal responses to opiate antagonist induction were monitored during anesthesia phase. Changes in plasma cortisol concentrations were measured as stress-response markers. Evaluations during early postanesthetic phase were based on Subjective and Objective Opiate Withdrawal Scales. Remote effects were assessed according to questionnaire based on Addiction Severity Index.
                Altogether, 50 patients were included in the final analysis. Ketamine group presented better control of withdrawal symptoms, which lasted beyond ketamine infusion itself. Significant differences between Ketamine and Control groups were noted in anesthetic and early postanesthetic phases. There were no differences in effects on outcome after 4 months.
                In this study, subanesthetic ketamine infusion was an effective adjuvant in the correction of acute precipitated opiate withdrawal although it had no long-term effects on treatment of opiate dependence. Rapid opioid detoxification with opioid antagonist induction using general anesthesia has emerged as an expensive, potentially dangerous, unproven approach to treat opioid dependence.
                To determine how anesthesia-assisted detoxification with rapid antagonist induction for heroin dependence compared with 2 alternative detoxification and antagonist induction methods.
                A total of 106 treatment-seeking heroin-dependent patients, aged 21 through 50 years, were randomly assigned to 1 of 3 inpatient withdrawal treatments over 72 hours followed by 12 weeks of outpatient naltrexone maintenance with relapse prevention psychotherapy. This randomized trial was conducted between 2000 and 2003 at Columbia University Medical Center's Clinical Research Center. Outpatient treatment occurred at the Columbia University research service for substance use disorders. Patients were included if they had an American Society of Anesthesiologists physical status of I or II, were without major comorbid psychiatric illness, and were not dependent on other drugs or alcohol.
                Anesthesia-assisted rapid opioid detoxification with naltrexone induction, buprenorphine-assisted rapid opioid detoxification with naltrexone induction, and clonidine-assisted opioid detoxification with delayed naltrexone induction.
                Withdrawal severity scores on objective and subjective scales; proportions of patients receiving naltrexone, completing inpatient detoxification, and retained in treatment; proportion of opioid-positive urine specimens.
                Mean withdrawal severities were comparable across the 3 treatments. Compared with clonidine-assisted detoxification, the anesthesia- and buprenorphine-assisted detoxification interventions had significantly greater rates of naltrexone induction (94% anesthesia, 97% buprenorphine, and 21% clonidine), but the groups did not differ in rates of completion of inpatient detoxification. Treatment retention over 12 weeks was not significantly different among groups with 7 of 35 (20%) retained in the anesthesia-assisted group, 9 of 37 (24%) in the buprenorphine-assisted group, and 3 of 34 (9%) in the clonidine-assisted group. Induction with 50 mg of naltrexone significantly reduced the risk of dropping out (odds ratio, 0.28; 95% confidence interval, 0.15-0.51). There were no significant group differences in proportions of opioid-positive urine specimens. The anesthesia procedure was associated with 3 potentially life-threatening adverse events.
                These data do not support the use of general anesthesia for heroin detoxification and rapid opioid antagonist induction. 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. New methods of rapid opiate detoxification, under intravenous sedation, can detoxify heroin-addicted patients in 24 hours. Their clinical application has been limited by the lack of studies establishing both efficacy and safety.
                In a randomised, controlled study, 300 treatment-refractory, heroin-addicted patients received rapid intravenous detoxification treatment (naloxone infusion, 0.06-0.08 mg/kg, then oral naltrexone 50 mg/day) under either monitored light intravenous sedation or unmonitored deep intravenous sedation.
                All patients were successfully detoxified and 93% remained abstinent one month later. Severity of withdrawal, according to the Wang Scale modified by Loimer, was 4.9 (s.d. 3.0) points in the light sedation group and 4.8 (s.d. 2.9) in the deep sedation group (P = 0.26). Two patients (1.3%) in the light sedation group and four (2.6%) in the deep sedation group required tracheal intubation (P = 0.31). There was only one severe complication, a case of nosocomial aspirative pneumonia which improved with antibiotic treatment.
                Successful rapid intravenous detoxification can be achieved using relatively light levels of sedation. Mu-Opioid receptor blockade during general anesthesia is a new treatment for detoxification of opioid addicted patients. We assessed catecholamine plasma concentrations, oxygen consumption, cardiovascular variables, and withdrawal symptoms after naloxone and tested the hypothesis that variables are influenced by the anesthetic administered during detoxification.
                Prospective randomized clinical study.
                Intensive care unit of a university hospital and psychiatric ward.
                Twenty-five mono-opioid addicted patients with mild to moderate systemic disease (ASA II classification) in a methadone substitution program.
                General anesthesia with either propofol (129+/-7 microg x kg(-1) x min(-1), mean +/- SEM) or methohexital (74+/-14 microg x kg(-1). min(-1)), mu-opioid receptor blockade by naloxone in a stepwise fashion (increasing doses of 0.4 mg, 0.8 mg, 1.6 mg, 3.2 mg, and 6.4 mg at 15 min intervals followed by 0.8 mg x hr(-1) for 24 hrs) and naltrexone 50 mg x day(-1) orally for > or =4 wks. Clonidine was started 180 mins after the first naloxone dose and its infusion rate was individually adjusted to mitigate withdrawal symptoms during weaning and after extubation.
                During propofol and methohexital anesthesia, naloxone induced a 30-fold increase in epinephrine and a significant three-fold increase in norepinephrine plasma concentrations without a significant difference between groups. This increase in catecholamine plasma concentrations was associated with increased oxygen consumption and marked cardiovascular stimulation with both anesthetics, as shown by increased cardiac index, heart rate, and systolic atrial pressure whereas diastolic pressure remained unchanged. Patients receiving propofol could be extubated significantly earlier after discontinuation of the anesthetics. Although the maximum degree of withdrawal symptoms (Short Opioid Withdrawal Scale) on the day after detoxification was similar with both anesthetics, subsequent withdrawal symptoms decreased significantly more rapidly after propofol anesthesia.
                Naloxone treatment, in opioid-addicted patients, induced a marked increase in catecholamine plasma concentrations, metabolism, and cardiovascular stimulation during anesthesia with both propofol and methohexital. Although both anesthetics appear suitable for detoxification treatment, the use of propofol is associated with earlier extubation and, surprisingly, a shortened period of long-term withdrawal symptoms during detoxification. The aim of this work was to study abstinence rates and withdrawal effects of rapid detoxification of opioid-dependents under general anaesthesia (RD-GA) compared to standard methadone tapering (SMT) using a prospective clinical trial with a follow-up of 3 months, as a preliminary study at the Novadic addiction centre in St Oedenrode and St Joseph Hospital in Veghel, the Netherlands. Thirty opioid-dependent patients took part. Outcome measures included urine toxicology screening for opiates to determine abstinence and presence of objective and subjective opioid withdrawal distress symptoms. Statistically significant differences in abstinence rate between RD-GA and SMT were present after one (RD-GA 100% vs. SMT 40%, p < 0.01) and 2 months (RD-GA 93% vs. SMT 33%, p < 0.01). After 3 months the difference in abstinence was still substantial, but no longer statistically significant (RD-GA 67% vs. SMT 33%, p = 0.14). Objective and subjective withdrawal symptoms showed largely identical outcomes and were equally low in the two groups for those who remained in the study. There was a considerably higher percentage of abstinence in the RD-GA group after 1, 2 and 3 months of follow-up accompanied by relatively mild withdrawal symptoms of shorter duration. However, if one completes SMT the data suggest a greater chance of staying clean in the long term than those completing RD-GA. While detoxification under anaesthesia accelerates the detoxification procedure, there is a lack of randomised clinical trials evaluating its effectiveness compared to traditional detoxification procedures, and a lack of data on long-term abstinence.
                Prospective randomised clinical trial. Analysis by intention to treat and per protocol. Setting: Specialised substance abuse unit in a psychiatric teaching hospital and an intensive care unit of a general hospital. Participants: Seventy patients with opiate mono-dependence requesting detoxification: 36 randomised to RODA (treatment as allocated received by 26) and 34 randomised to classical clonidine detoxification (treatment as allocated received by 21). Main outcome measures: Successful detoxification, safety and self-reported abstinence at 3, 6 and 12 months after detoxification.
                Socio-demographics were similar in both groups at baseline. No complications were reported during or after anaesthesia. According to the intention to treat analysis, 28/36 (78%) RODA patients and 21/34 (62%) of the clonidine group successfully completed the detoxification process (p=0.14). In the intention to treat analysis, 30% of RODA patients were abstinent after 3 months compared to 14% in the clonidine group (p=0.11). No difference was found at 6 and 12 months (both groups showed less than 5% abstinence after 12 months). The per-protocol analysis showed similar results with no statistical differences either for ASI mean scores or for the SF36 questionnaire.
                Although the detoxification success rate and abstinence after 3 months were slightly better for the RODA procedure compared to clonidine treatment, these differences were not statistically significant and disappeared completely after 6 and 12 months.
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.