Case study: paradoxical response to naltrexone treatment of self-injurious behavior

The status of pharmacotherapy for autism spectrum disorders

The use of pharmacologic agents as a component of treatment for children and adults with autism spectrum disorders is common and a substantial body of literature describing controlled and open-label clinical trials now exists to guide clinical practice. Empiric evidence of efficacy of risperidone, methylphenidate and some selective serotonin re-uptake inhibitors for maladaptive behaviors commonly associated with autism spectrum disorders has increased substantially in recent years. Preliminary controlled trials of valproate, atomoxetine, alpha-2 adrenergic agonists and olanzapine are promising. In addition to traditional psychotropic medications, investigators have examined the potential role of a variety of agents with glutamatergic or cholinergic mechanisms, and the results warrant further investigation. Although psychotropic medications are effective in treating some important associated behaviors, evidence of significant impact on the core features of autism spectrum disorders is very limited.

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.

Self-injurious behavior and the efficacy of naltrexone treatment: a quantitative synthesis

People with mental retardation, autism, and related developmental disabilities who self-injure are treated with a wide array of behavioral techniques and psychotropic medications. Despite numerous reports documenting short-term and some long-term changes in self-injury associated with the opiate antagonist naltrexone hydrochloride, no quantitative review of its efficacy has been reported. We conducted a quantitative synthesis of the peer-reviewed published literature from 1983 to 2003 documenting the use of naltrexone for the treatment of self-injurious behavior (SIB). Individual-level results were analyzed given subject and study characteristics. A sample of 27 research articles involving 86 subjects with self-injury was reviewed. Eighty percent of subjects were reported to improve relative to baseline (i.e., SIB reduced) during naltrexone administration and 47% of subjects SIB was reduced by 50% or greater. In studies reporting dose levels in milligrams, males were more likely than females to respond. No significant relations were found between treatment outcomes and autism status or form of self-injury. Results are discussed with respect to future efficacy work related to study outcomes and the pharmacological treatment of self-injury.

Psychopharmacology and mental retardation: a 10 year review (1990-1999)

We conducted a 10 year review of the literature pertaining to psychopharmacology and mental retardation. Studies were included or excluded from the review based on meeting one or more of the methodological criteria normally considered fundamental for sound scientific research. The vast majority of studies conducted in the last 10 years in this area had major methodological flaws. While a large number of medications were prescribed for various psychological disorders and behavior problems, most drug administrations were not based in science, were not evaluated appropriately, and generally did not follow best practices for treatment of persons with mental retardation. Very few medications prescribed were behavior or psychiatric symptom specific; that is, most medications were given to suppress a myriad of aberrant behaviors thus chemically restraining the individual in question. Practices such as these present serious problems for service providers due to the deleterious side effects of many psychotropic medications and the federal government's intervention into the care-provision practices of developmental centers, community homes, and other living arrangements for persons with mental retardation. Implications of our review are discussed.

Practice parameters for the assessment and treatment of children, adolescents, and adults with mental retardation and comorbid mental disorders. American Academy of Child and Adolescent Psychiatry Working Group on Quality Issues

Mental retardation (MR) is a heterogeneous condition defined by significantly subaverage intellectual and adaptive functioning and onset before age 18 years. With an approach underscored by principles of normalization and the availability of appropriate education and habilitation, persons with MR generally live, are educated, and work in the community. Mental disorders occur more commonly in persons with MR than in the general population. However, the disorders themselves are essentially the same. Clinical presentations can be modified by poor language skills and by life circumstances, so a diagnosis might hinge more heavily on observable behavioral symptoms. The diagnostic assessment considers and synthesizes the biological, psychological, and psychosocial context of mental disorders. Comprehensive treatment integrating various approaches, including family counseling, pharmacological, educational, habilitative, and milieu interventions is the rule.

Using analog baselines to assess the effects of naltrexone on self-injurious behavior

Naltrexone (NLTX), an opiate receptor antagonist, has been prescribed as a pharmacological intervention for the treatment of self-injurious behavior (SIB). Previous research has investigated NLTX's effects in the absence of information about the role of environmental events related to SIB. This study extended previous analyses by administering NLTX on analog baselines using a double-blind, placebo-controlled reversal design. Pretreatment functional analysis results showed that the SIB of the two participants occurred in more that one assessment condition. For one participant NLTX produced slight reductions in SIB across baseline conditions. The second participant's results showed that NLTX reduced head-slapping occurring during demand sessions, but had no apparent effect on head-banging occurring during alone and demand sessions. These outcomes suggest that NLTX may have function- and/or response-specific treatment effects. The potential utility of this model as a general method for assessing pharmacological interventions, as well as other implications and limitations, are discussed.

Prognosis in autism: do specialist treatments affect long-term outcome?

Many different treatments have been claimed to have a dramatic impact on children with autism. This paper reviews what is known about the outcome in adult life and examines the limitations and advantages of a variety of intervention approaches. It concludes that there is little evidence of any "cure" for autism, but appropriately structured programmes for education and management in the early years can play a significant role in enhancing functioning in later life.

A risk-benefit assessment of naltrexone in the treatment of alcohol dependence

There is a great deal of interest in the use of naltrexone as a treatment for alcohol (ethanol) dependence since there is a rapidly expanding body of evidence to support its efficacy and tolerability in this indication. Naltrexone, a long-acting, nonselective opioid receptor antagonist has been shown to reduce alcohol intake when combined with behavioural treatment. Naltrexone may prevent the return to clinically significant drinking by blocking the pleasurable effects or "high' associated with alcohol drinking. Results from controlled studies showed that in alcohol dependent patients taking naltrexone 50 mg/day in combination with behavioural treatment, relapse rates were reduced by 50% compared with placebo treated patients. Historically, several factors have limited the use of effective pharmacological adjuncts in the treatment of alcohol dependence. These include safety considerations in this vulnerable population, and the fact that some treatment programmes discourage alcohol-dependent patients from taking medications. The most common adverse effects reported with the use of naltrexone at a dosage of 50 mg/day include nausea and vomiting. Naltrexone does not appear to be hepatotoxic in dosages recommended in the treatment of alcohol dependence, i.e. 50 mg/day. Thus, naltrexone appears to offer significant therapeutic benefits at a relatively low risk, when used judiciously and with behavioural treatment for alcohol dependent patients.