The impact of alcohol dependence and posttraumatic stress disorder on cold pressor task response

OBJECTIVE

Posttraumatic stress disorder (PTSD) is commonly comorbid with alcohol-use disorders. Abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis response are common in both disorders. The objective of this study was to investigate HPA axis reactivity to the cold pressor task (CPT) among individuals with alcohol dependence, PTSD, and comorbid alcohol dependence and PTSD.

METHOD

Participants were 119 individuals with alcohol dependence only (n = 31), comorbid alcohol dependence and PTSD (n = 28), PTSD without alcohol dependence (n = 30), and a control group (n = 30). Subjective response, adrenal corticotropic hormone (ACTH), and cortisol were measured before, immediately after, and for 120 minutes after each subject completed the CPT.

RESULTS

There were significant group and gender differences found in the subjective and ACTH response, with significantly higher subjective stress ratings and decreased ACTH response in the alcohol-dependent, PTSD, and comorbid alcohol dependent-PTSD groups compared with the control group.

CONCLUSIONS

There were differences in the HPA axis and subjective response to the CPT between the control group and both the alcohol and PTSD groups. The HPA response in the comorbid alcohol-PTSD group was not significantly different than that of the alcohol-only or PTSD-only groups.

Buprenorphine Use: The International Experience

The confluence of the heroin injection epidemic and the human immunodeficiency virus (HIV) infection epidemic has increased the call for expanded access to effective treatments for both conditions. Buprenorphine and methadone are now listed on the World Health Organization's Model Essential Drugs List. In France, which has the most extensive experience, buprenorphine has been associated with a dramatic decrease in deaths due to overdose, and buprenorphine diversion appears to be associated with inadequate dosage, social vulnerability, and prescriptions from multiple providers. Other treatment models (in the United States, Australia, Germany, and Italy) and buprenorphine use in specific populations are also reviewed in the present article. In countries experiencing a dual epidemic of heroin use and HIV infection, such as former states of the Soviet Union and other eastern European and Asian countries, access to buprenorphine and methadone may be one potential tool for reducing the spread of HIV infection among injection drug users and for better engaging them in medical care.

Opioid Dependence: Rationale for and Efficacy of Existing and New Treatments

Opioid dependence is a chronic and relapsing medical disorder with a well-established neurobiological basis. Opioid agonist treatments, such as methadone and the recently approved buprenorphine, stabilize opioid receptors and the intracellular processes that lead to opioid withdrawal and craving. Both methadone and buprenorphine have been proven effective for the treatment of opioid dependence and can contribute to a decreased risk of human immunodeficiency virus (HIV) transmission. In addition, a buprenorphine/naloxone combination appears to have a decreased potential for abuse or diversion, compared with that associated with methadone. Largely because of these properties, recent legislation now affords an unprecedented opportunity for general physicians to offer opioid agonist treatment through their offices. This review focuses on the neurobiological basis of opioid dependence, the rationale for methadone and buprenorphine treatments, and issues in prescribing these medications to patients with HIV infection.

Pharmacokinetic Interactions between Buprenorphine and Antiretroviral Medications

Buprenorphine is used for the treatment of opioid dependence. As the number of persons receiving buprenorphine treatment and antiretroviral therapy continues to grow, so too does the existence and clinical impact of drug interactions between buprenorphine and medications for treating human immunodeficiency virus (HIV) infection. Awareness that such interactions exist may deter some patients and physicians from initiating potentially lifesaving therapy or lead to complications among patients whose treatment is already under way. Complications include nonadherence to antiretroviral therapy and the development of viral resistance. Illicit drug use is a frequent consequence of adverse drug effects experienced by injection drug users. The occurrence of unrecognized drug interactions can lead to unsuccessful therapy for HIV infection and the treatment of substance dependence. The present review is organized to provide a working background of buprenorphine pharmacology. Review of the current state of knowledge regarding specific interactions between buprenorphine and antiretrovirals is followed by a review of the clinical applicability of these interactions.

Buprenorphine and HIV Primary Care: New Opportunities for Integrated Treatment

Drug abuse and infection with human immunodeficiency virus (HIV) are associated with high rates of morbidity and mortality, but, because of medical, social, and legal factors, opiate addiction/dependence is a major obstacle to successful treatment of disease--for example, treatment of acquired immunodeficiency syndrome (AIDS) with highly active antiretroviral therapy. In an effort to improve the opportunity for treatment of drug abuse and HIV infection, the Forum for Collaborative HIV Research, in collaboration with the Substance Abuse and Mental Health Services Administration, the National Institute on Drug Abuse, the Centers for Disease Control and Prevention, and other agencies, presented a workshop entitled "Buprenorphine in the Primary HIV Care Setting." Participants reviewed and discussed current issues, such as the introduction of and sources for the provision of buprenorphine in HIV primary care settings and strategies for integrating treatment of HIV-infected drug abusers, all of which are covered in this supplement.

Buprenorphine-containing treatments: place in the management of opioid addiction

Although the synthetic opioid buprenorphine has been available clinically for almost 30 years, its use has only recently become much more widespread for the treatment of opioid addiction. The pharmacodynamic and pharmacokinetic profiles of buprenorphine make it unique in the armamentarium of drugs for the treatment of opioid addiction. Buprenorphine has partial mu-opioid receptor agonist activity and is a kappa-opioid receptor antagonist; hence, it can substitute for other micro-opioid receptor agonists, yet is less apt to produce overdose reactions or dysphoria. On the other hand, buprenorphine can block the effects of opioids such as heroin (diamorphine) and morphine, and can even precipitate withdrawal in individuals physically dependent upon these drugs. Buprenorphine has significant sublingual bioavailability and a long half-life, making administration on a less than daily basis possible. Furthermore, its discontinuation is associated with only a mild withdrawal syndrome. Clinical trials have demonstrated that sublingual buprenorphine is effective in both maintenance therapy and detoxification of individuals addicted to opioids. The introduction of a sublingual formulation combining naloxone with buprenorphine further reduces the risk of diversion to illicit intravenous use. Because of its relative safety and lower risk of illegal diversion, buprenorphine has been made available in several countries for treating opioid addiction in the private office setting, greatly enhancing treatment options for this condition.

The medical management of opioid dependence in HIV primary care settings

Injecting drug use is a common mode of transmission among persons with HIV/AIDS. Many HIV-infected patients meet diagnostic criteria for opioid dependence, a chronic and relapsing brain disorder. Most HIV providers, however, receive little training in substance use disorders. Opioid agonist therapy (OAT) has a stabilizing effect on opioid-dependent patients and is associated with greater acceptance of antiretroviral (ARV) therapy, higher ARV adherence, and greater engagement in HIV-related health care. Although methadone maintenance has been the OAT gold standard, methadone is available for the treatment of opioid dependence only in strictly regulated narcotic treatment programs. Buprenorphine, a partial opioid agonist approved for the office-based treatment of opioid dependence in 2002, may result in better health and substance use treatment outcomes for patients with HIV disease.

Naltrexone with or without fluoxetine for preventing relapse to heroin addiction in St. Petersburg, Russia

This randomized placebo-controlled trial tested the efficacy of oral naltrexone with or without fluoxetine for preventing relapse to heroin addiction and for reducing HIV risk, psychiatric symptoms, and outcome. All patients received drug counseling with parental or significant-other involvement to encourage adherence. Patients totaling 414 were approached, 343 gave informed consent, and 280 were randomized (mean age, 23.6 +/- 0.4 years). At 6 months, two to three times as many naltrexone patients as naltrexone placebo patients remained in treatment and had not relapsed, odds ratio (OR) = 3.5 (1.96-6.12), p < .0001. Overall, adding fluoxetine did not improve outcomes, OR = 1.35 (0.68-2.66), p = .49; however, women receiving naltrexone and fluoxetine showed a trend toward a statistically significant advantage when compared to women receiving naltrexone and fluoxetine placebo, OR = 2.4 (0.88-6.59), p = .08. HIV risk, psychiatric symptoms, and overall adjustment were markedly improved among all patients who remained on treatment and did not relapse, regardless of group assignment. More widespread use of naltrexone could be an important addition to addiction treatment and HIV prevention in Russia.

Effects associated with double-blind omission of buprenorphine/naloxone over a 98-h period

RATIONALE

Buprenorphine has a long duration of action that allows less than daily dosing for opioid dependence, but pharmacologic characterization of buprenorphine's duration of effects over multiple days is incomplete.

OBJECTIVES

This study assessed opioid blockade and spontaneous withdrawal effects of buprenorphine/naloxone (B/N) over a 98-h period.

MATERIALS AND METHODS

Residential opioid-dependent volunteers (n = 8) were maintained, in randomized sequence, on each of three different daily sublingual B/N doses (8/2, 16/4, 32/8 mg). After 2 weeks on each maintenance dose, participants underwent challenge sessions on each weekday for 1 week. Challenges consisted of within-session, ascending dose administration of IM hydromorphone (H: 0, 6, and 12 mg). During that week, active B/N dose was given only on Monday; double-blind placebo was administered on the remaining weekdays. Thus, these sessions assessed the extent of both opioid blockade and spontaneous withdrawal at 2, 26, 50, 74, and 98 h after the last active B/N dose.

RESULTS

All three maintenance doses provided substantial but incomplete blockade against opioid agonist effects for 98 h. The extent of blockade diminished steadily but modestly over this time and did not differ as a function of B/N maintenance dose. In general, participants did not report marked spontaneous opioid withdrawal, although mild withdrawal effects were observed as time since the last active B/N dose increased. However, withdrawal did not differ as a function of B/N maintenance dose.

CONCLUSIONS

These findings suggest that B/N doses greater than 8/2 mg provide minimal incremental value in terms of opioid blockade and withdrawal suppression.

Trends in the adoption of medications for alcohol dependence

Increasing attention is being paid to the development and dissemination of effective pharmacotherapies for the treatment of alcohol and other drug dependence. However, numerous structural and philosophical barriers impede the widespread adoption of these treatment approaches in everyday clinical practice. Research is needed to understand and overcome this gap. Drawing upon data collected from 2 large samples of substance abuse treatment providers at multiple time points, this article examines the prevalence and correlates of the adoption of the currently available pharmacotherapies for alcohol dependence: disulfiram, oral naltrexone, and acamprosate. These data suggest that the proportion of treatment programs using pharmacotherapies for alcohol dependence has been declining over time. In addition, the proportion of patients to whom these medications are prescribed is notably low. The adoption of disulfiram and naltrexone is significantly more likely in programs that are accredited, employ at least 1 physician, offer integrated care for patients with co-occurring psychiatric conditions, derive proportionately more revenue from commercial insurance payers, and have fewer linkages with the criminal justice system. Preliminary data suggest that the early adoption of acamprosate is following a similar pattern. Recommendations for addressing challenges to the diffusion of pharmacotherapies for alcohol dependence are presented.

The status of naltrexone in the treatment of alcohol dependence: specific effects on heavy drinking

BACKGROUND

In almost 2 decades of naltrexone research for treating alcoholism, there have been 29 published randomized placebo-controlled trials of opioid antagonists, primarily naltrexone, for the treatment of alcohol dependence. The present review builds on prior systematic reviews while maximizing the number of included studies to date, for the purpose of resolving inconsistencies in naltrexone's reported efficacy across trials. Clinical trial results in this article are evaluated by the type of outcome measure used to determine naltrexone's treatment advantage, that is, measures related to reducing heavy drinking versus those related to increasing abstinence.

METHODS

We conducted a Medline search to identify double-blind studies from 1990 to the present (2006) that evaluated the use of anopiate antagonist for the treatment of alcohol dependence. There were 29 studies identified, representing 5997 alcohol-dependent patients, which met our study inclusion criteria for this review. Studies were evaluated in this review on 4 prespecified drinking outcomes-2 related to "any drinking" and 2 related to "heavy or excessive drinking."

RESULTS

In the treatment of alcohol dependence, we found that 19 (70%) of 27 clinical trials that measured reductions in "heavy or excessive drinking" demonstrated an advantage for prescribing naltrexone over placebo, whereas only 9 (36%) of 25 clinical trials that measured abstinence or "any drinking" found an advantage for medication over placebo.

CONCLUSION

The majority of double-blind clinical trials in the literature favored prescribing naltrexone for alcohol dependence to reduce heavy drinking. This finding is consistent with our understanding of naltrexone's mechanism of action of decreasing excessive drinking by reducing the reward associated with drinking alcohol. Thus, we conclude that outcome measures related to heavy or excessive drinking are most relevant to defining naltrexone's therapeutic effects. Factors influencing naltrexone response (treatment adherence and distinct patient subgroups) are also discussed.

Enhanced Analgesia with Opioid Antagonist Administration

BACKGROUND

Pain, not responsive to opioid analgesics, remains a problem for patients with chronic and cancer pain as well as their families, and clinicians. Opioid antagonists have various uses in pain and palliative care. Their use in the reversal of tolerance and hyperalgesia remains at the basic science level and has limited clinical exposure.

OBJECTIVE

To improve symptom control and quality of life in patients with pain not responsive to opioid analgesics.

DESIGN

Present three cases in which patients have undergone administration of opioid antagonists for the purpose of analgesia.

METHODS

Patients on opioids analgesics received parenteral opioid antagonist, naloxone. Complete withdrawal under a sedative or conscious sedation was allowed and then the opioid at smaller doses was restarted and analgesia was observed.

RESULTS

All patients had improved analgesia on a significantly lower dose of opioid analgesics.

CONCLUSIONS

Only three patients who have received this procedure were presented yet all have responded positively to this procedure. Further research is needed to elucidate the mechanism and clinical relevance in the acute use of opioid antagonists.

Low-dose naltreoxone for the treatment of irritable bowel syndrome: a pilot study

Preclinical studies have shown that a very low dose of naltreoxone hydrochloride (NTX), an opiate antagonist, can block excitatory opioid receptors without affecting inhibitory opioid receptors, resulting in analgesic potency without side effects. The present study assessed the efficacy and safety of PTI-901 (low-dose NTX) treatment in Irritable bowel syndrome (IBS) patients. Forty-two IBS patients participated in an open-label study. Participants received 0.5 mg PTI-901/day for 4 weeks and were evaluated during baseline, during treatment, and at 4-week follow-up. Patients recorded degree of abdominal pain, stool urgency, consistency, and frequency. Primary outcomes were number of pain-free days and overall symptom relief, evaluated by a global assessment score. Data were analyzed per protocol. Global assessment improved in 76% of 42 patients. During treatment, the mean weekly number of pain-free days increased from 0.5+/-1 to 1.25+/-2.14 (P=0.011). There were no significant adverse reactions. PTI-901 improves pain and overall feeling, and is well tolerated by IBS patients. A large, randomized, double-blind, placebo-controlled study is justified.

Using buprenorphine to facilitate entry into residential therapeutic community rehabilitation

For opioid-dependent patients, the need for detoxification has been a barrier to entry into long-term residential treatment. This report describes a retrospective observational cohort study with the first 38 opioid-dependent patients entering First Step, a 14-day buprenorphine-naloxone (Suboxone) detoxification regimen integrated into a long-term residential therapeutic community (TC) program. Eighty-nine percent (34 of 38) of First Step patients completed a 14-day buprenorphine taper protocol, 50% (19 of 38) completed an initial 3- to 4-week stay, and 39% (15 of 38) completed at least 3 months of residential treatment at the TC. Retention did not differ significantly in a demographically matched concurrently admitted control group without impending opioid withdrawal, in which 65% (24 of 37) completed an initial 3- to 4-week stay (p = .20) and 57% (21 of 37) completed at least 3 months of treatment (p = .14). Withdrawal symptoms were mild, and there were no instances of precipitated withdrawal. The findings suggest the potential for buprenorphine to serve as a bridge, improving the viability of long-term residential treatment for managing opioid dependence.

Novel pharmacological targets for the treatment of Parkinson's disease

Dopamine deficiency, caused by the degeneration of nigrostriatal dopaminergic neurons, is the cause of the major clinical motor symptoms of Parkinson's disease. These symptoms can be treated successfully with a range of drugs that include levodopa, inhibitors of the enzymatic breakdown of levodopa and dopamine agonists delivered by oral, subcutaneous, transcutaneous, intravenous or intra-duodenal routes. However, Parkinson's disease involves degeneration of non-dopaminergic neurons and the treatment of the resulting predominantly non-motor features remains a challenge. This review describes the important recent advances that underlie the development of novel dopaminergic and non-dopaminergic drugs for Parkinson's disease, and also for the motor complications that arise from the use of existing therapies.

Naltrexone reverses age-induced cognitive deficits in rats

We evaluated young (3-4 months) and aged (22-24 months) male Sprague-Dawley rats in an attentional set-shifting procedure that assessed reversal, intradimensional shift (IDS), and extradimensional shift (EDS) discrimination learning tasks within one test session. These aspects of discrimination learning are sensitive to damage to distinct regions of frontal cortex. Compared to young animals, aged rats were significantly impaired on the EDS task and did not demonstrate significant impairment on the reversal or IDS tasks. The opioid antagonist naltrexone (2mg/kg, ip) was administered to young and aged rats prior to testing to assess possible improvements in aged-related cognitive impairments. Naltrexone (2mg/kg) attenuated the impairments in cognitive function in the EDS task for aged animals, but did not alter any task performance in the younger group. These results suggest that normal aging in rats is associated with impaired medial frontal cortex function as assessed by this attentional set-shifting procedure and opioid mediated mechanisms may represent a therapeutic target for drugs to improve cognitive deficits associated with aging.

Naltrexone, an opioid receptor antagonist, attenuates liver fibrosis in bile duct ligated rats

AIM

The aim of this study was to investigate the hypothesis that the opioid system is involved in the development of hepatic fibrosis.

METHODS

The effect of naltrexone (an opioid receptor antagonist) on hepatic fibrosis in bile duct ligated (BDL) or sham rats was assessed by histology and hepatic hydroxyproline levels. Liver matrix metalloproteinase 2 (MMP-2) was measured by zymography, and alpha smooth muscle actin (alpha-SMA) and CD45 (leucocyte common antigen) by immunohistochemistry. The redox state of the liver was assessed by hepatic glutathione (GSH)/oxidised glutathione (GSSG) and S-nitrosothiol levels. Subtypes of opioid receptors in cultured hepatic stellate cells (HSCs) were characterised by reverse transcriptase-polymerase chain reaction, and the effects of selective delta opioid receptor agonists on cellular proliferation, tissue inhibitor of metalloproteinase 1 (TIMP-1), and procollagen I expression in HSCs determined.

RESULTS

Naltrexone markedly attenuated the development of hepatic fibrosis as well as MMP-2 activity (p<0.01), and decreased the number of activated HSCs in BDL rats (p<0.05). The development of biliary cirrhosis altered the redox state with a decreased hepatic GSH/GSSG ratio and increased concentrations of hepatic S-nitrosothiols, which were partially or completely normalised by treatment with naltrexone, respectively. Activated rat HSCs exhibited expression of delta1 receptors, with increased procollagen I expression, and increased TIMP-1 expression in response to delta(1) and delta(2) agonists, respectively.

CONCLUSIONS

This is the first study to demonstrate that administration of an opioid antagonist prevents the development of hepatic fibrosis in cirrhosis. Opioids can influence liver fibrogenesis directly via the effect on HSCs and regulation of the redox sensitive mechanisms in the liver.

Naltrexone and buprenorphine combination in the treatment of opioid dependence

Naltrexone treatment has demonstrated some advantages for special populations of heroin addicted individuals, but patients' compliance seems to be very poor, with a low adherence and low retention rate. Kappa-opioid system overdrive seems to contribute to opioid protracted abstinence syndrome, with dysphoria and psychosomatic symptoms during naltrexone treatment. The objective of this observational study was to determine the effectiveness of a functional k antagonist in improving naltrexone treatment outcome. A partial mu agonist/kappa antagonist (buprenorphine) and a mu antagonist (naltrexone) were combined during a 12 weeks protocol, theoretically leaving k antagonism as the major medication effect. Sixty patients were submitted to outpatient rapid detoxification utilizing buprenorphine and opioid antagonists. Starting on the fifth day, 30 patients (group A) received naltrexone alone. Alternatively, 30 patients (group B) received naltrexone (50mg oral dose) plus buprenorphine (4 mg sublingual) for the 12 weeks of the observational study. The endpoints of the study were: retention in treatment, negative urinalyses, changes in psychological symptoms (Symptom Checklist-90 Revised: SCL-90) and craving scores (visual analysis scale (VAS)). Thirty-four subjects (56.67%) completed the 12 weeks study. Twenty-one patients (35.0%) had all urine samples negative for opiates and cocaine. nine subjects (15.0%) had urine samples negative for cocaine and opiates for the last 4 weeks of the study. five subjects (8.3%) continued to use cocaine during the 12 weeks of the study. No significant change in pupillary diameter after buprenorphine administration was evidenced during clinical observations from baseline across the weekly measurements. Retention rates in group A (naltrexone) and group B (naltrexone + buprenorphine) at week 12 were respectively 40% (12 patients) and 73.33% (22 patients), with a significant difference in favour of group B (p= 0.018). Patients treated with naltrexone in combination with buprenorphine (B patients) showed a significantly lower rate of positive urines for morphine (4.45%) and cocaine metabolites (9.09%) than those treated with naltrexone alone (A) (25%, morphine; 33.33% cocaine) (p< 0.05; p< 0.05). Irritability, depression, tiredness, psychosomatic symptoms and craving scores decreased significantly less in Group A patients than in group B patients. The dysfunction of opioid system with kappa receptors hyper-activation provoked by heroin exposure, probably underlying dysphoric and psychosomatic symptoms during naltrexone treatment, seems to be counteracted, at least in part, by buprenorphine. The combination of buprenorphine and naltrexone may significantly improve the outcome of opioid antagonists treatment in terms of retention, negative urinalyses, and reduced dysphoria, mood symptoms and craving.

Delta receptor antagonism, ethanol taste reactivity, and ethanol consumption in outbred male rats

Naltrexone, a nonspecific opioid antagonist, produces significant changes in ethanol responsivity in rats by rendering the taste of ethanol aversive as well as producing a decrease in voluntary ethanol consumption. The present study investigated the effect of naltrindole, a specific antagonist of delta opioid receptors, on ethanol taste reactivity and ethanol consumption in outbred rats. In the first experiment, rats received acute treatment of naltrexone, naltrindole, or saline followed by the measurement of ethanol consumption in a short-term access period. The second experiment involved the same treatments and investigated ethanol palatability (using the taste-reactivity test) as well as ethanol consumption. Results indicated that treatment with 3 mg/kg naltrexone significantly affected palatability (rendered ethanol more aversive, Experiment 2) and decreased voluntary ethanol consumption (Experiments 1 and 2). The effects of naltrindole were inconsistent. In Experiment 1, 8 mg/kg naltrindole significantly decreased voluntary ethanol consumption but this was not replicated in Experiment 2. The 8 mg/kg dose produced a significant increase in aversive responding (Experiment 2) but did not affect ingestive responding. Lower doses of naltrindole (2 and 4 mg/kg) were ineffective in altering rats' taste-reactivity response to and consumption of ethanol. While these data suggest that delta receptors are involved in rats' taste-reactivity response to ethanol and rats' ethanol consumption, it is likely that multiple opioid receptors mediate both behavioral responses.

Intravenous nalbuphine 50 microg x kg(-1) is ineffective for opioid-induced pruritus in pediatrics

PURPOSE

This investigation evaluated the efficacy of nalbuphine in treating postoperative opioid-induced pruritus (Pr) in pediatric patients.

METHODS

After Ethics Board approval, the dual site, tertiary care teaching centre study recruited 212 subjects, age > or = seven years, who received opioid analgesia postoperatively. A modified, self-report colour analogue scale (CAS) scored pruritus intensity (PrI). Subjects who reported PrI score > or = 5/10 were randomized to treatment with nalbuphine 50 microg x kg(-1) iv (max 5 mg) or saline placebo. A pruritus intensity difference (PrID) > or = 50% was considered a positive outcome.

RESULTS

Of 260 subjects approached, 212 consented and 184 received opioids. Median age was 13 yr (range 7-19) and median weight was 51 kg (range 19.6-134.8 kg). Pruritus intensity > or = 5/10 occurred in 37 (20.1%) subjects. Intravenous morphine [patient-controlled analgesia (PCA)/continuous infusion] was associated with Pr in 68% of subjects over a wide dose range (9.4-63.2 mug.kg(-1).hr(-1)). Pruritus occurred in 36% of patients in the PCA group compared to continuous opioid infusion (27%) and epidural administration (27%). Pruritus intensity difference > or = 50% was achieved in 55.6% of nalbuphine and 57.9% of saline-treated subjects.

CONCLUSION

This preliminary report suggests that nalbuphine 50 microg x kg(-1) iv is not effective in treating postoperative opioid-induced pruritus in pediatric patients. The modified CAS score and PrID warrant further investigation.

Early adoption of buprenorphine in substance abuse treatment centers: data from the private and public sectors

The recent approval of buprenorphine for the treatment of opiate dependence offers an opportunity to analyze innovation adoption in community-based treatment. Using data collected from national samples of 299 privately funded and 277 publicly funded treatment centers, this research examines buprenorphine adoption using baseline data collected between 2002 and 2004 as well as follow-up data collected 12 months later. Private centers were significantly more likely than public centers to report current use of buprenorphine. The baseline data indicated that early adoption was positively associated with center accreditation, physician services, availability of detoxification services, current use of naltrexone, and the percentage of opiate-dependent clients. Multivariate analyses of follow-up data suggest that adoption was greater in accredited centers, for-profit facilities, organizations offering detoxification services, and naltrexone-using centers. Future research should continue to monitor the extent to which buprenorphine is adopted in these settings.

Opioid antagonists for smoking cessation

BACKGROUND

The reinforcing properties of nicotine may be mediated through release of various neurotransmitters both centrally and systemically. Smokers report positive effects such as pleasure, arousal, and relaxation as well as relief of negative affect, tension, and anxiety. Opioid (narcotic) antagonists are of particular interest to investigators as potential agents to attenuate the rewarding effects of cigarette smoking.

OBJECTIVES

To evaluate the efficacy of opioid antagonists in promoting long-term smoking cessation. The drugs include naloxone and the longer-acting opioid antagonist naltrexone.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group specialized register for trials of naloxone, naltrexone and other opioid antagonists and conducted an additional search of MEDLINE using 'Narcotic antagonists' and smoking terms in March 2006. We also contacted investigators, when possible, for information on unpublished studies.

SELECTION CRITERIA

We considered randomized controlled trials comparing opioid antagonists to placebo or an alternative therapeutic control for smoking cessation. We included in the meta-analysis only those trials which reported data on abstinence for a minimum of six months. We also reviewed, for descriptive purposes, results from short-term laboratory-based studies of opioid antagonists designed to evaluate psycho-biological mediating variables associated with nicotine dependence.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of study population, the nature of the drug therapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was cotinine- or carbon monoxide-verified abstinence from smoking after at least six months follow up in patients smoking at baseline. Where appropriate, we performed meta-analysis using a fixed-effect model (Mantel-Haenszel odds ratios).

MAIN RESULTS

Four trials of naltrexone met inclusion criteria for meta-analyses for long-term cessation. All four trials failed to detect a significant difference in quit rates between naltrexone and placebo. In a pooled analysis there was no significant effect of naltrexone on long-term abstinence, and confidence intervals were wide (odds ratio 1.26, 95% confidence interval 0.80 to 2.01). No trials of naloxone or buprenorphine reported long-term follow up.

AUTHORS' CONCLUSIONS

Based on limited data from four trials it is not possible to confirm or refute whether naltrexone helps smokers quit. The confidence intervals are compatible with both clinically significant benefit and possible negative effects of naltrexone in promoting abstinence. Data from larger trials of naltrexone are needed to settle the question of efficacy for smoking cessation.

Less Pain, More Gain

Research indicates that persons addicted to opiates are likely to relapse following treatment or are at risk of terminating treatment early. The withdrawal experience may be one factor underlying early treatment discharge and several medications, including buprenorphine-naloxone, have been used to reduce withdrawal symptoms during detoxification. This retrospective study sought to determine whether patients who received buprenorphine-naloxone were retained in treatment longer than those who did not receive the medication. Data were collected on 170 patients admitted to the detoxification unit who either received (n = 85) or did not receive (n = 85) the medication. Differences in lengths of stay were found between the groups, thus warranting future research on the usefulness of buprenorphine-naloxone during detoxification and subsequent treatment. The importance of detoxification as an initial phase of treatment in relation to patient retention is discussed.