Ultra-Low Dose Oral Naltrexone Decreases Side Effects and Potentiates the Effect of MethadoneTo the Editor:The use of N-methyl-D-aspartate (NMDA) receptor antagonists to decrease opioid side effects, potentiate opioid actions, and decrease the development of tolerance has been a topic of substantial interest over the last decade. The pioneering work by Trujillo and Akil suggested that tolerance to opioids could be prevented by the non-competitive NMDA receptor antagonist MK-801. 1 Subsequent studies indicated that competitive NMDA receptor antagonists could prevent the development of opioid tolerance and reverse it once established. 2 To determine the clinical significance of these observations, numerous clinical trials have been performed with the widely used NMDA receptor antagonists ketamine and dextromethorphan. These studies suggest that both antagonists can improve pain scores in patients with certain types of pain, but, in general, the doses must be high, which predisposes to significant side effects. 3 The addition of dextromethorphan to morphine has been studied in both animals and humans. Mao et al. conducted animal studies to determine the optimal ratio and concluded that a 1:1 ratio was the most efficacious. 4 More recently, clinical trials performed to study this combination yielded inconclusive results, and more studies are needed to determine the correct ratio in humans. In view of the limited benefit obtained by this approach, other strategies to potentiate, decrease side effects, and prevent the development of tolerance to opioids are being explored.One novel strategy was suggested by work performed by Crain and Shen 5,6 about a decade

This is a prospective pilot study looking at the utility of Transcutaneous Electrical Nerve Stimulator (TENS) trial as a screening tool prior to spinal cord stimulator (SCS) implant to identify patients who may fail a SCS trial. The accepted screening test prior to a permanent SCS implant is a SCS trial. Patients may fail the SCS trial due to several causes of which one is the inability to tolerate stimulation induced paresthesias. Twenty five patients scheduled for a SCS trial for the treatment of refractory pain secondary to Failed Back surgery syndrome underwent a TENS trial and psychological evaluation by personnel uninvolved in the SCS trial. Data was collected by personnel not involved in the SCS trial or permanent placement. Twenty patients completed the study. Data collected included area of coverage, paresthesia tolerance, pain and anxiety measured on a VAS scale. Comparability between the groups were analyzed using Pearson's correlation, Fisher Exact test and simple regression analysis. We noted a significant correlation between ability to tolerate TENS and SCS induced paresthesias. Statistically significant correlation was also noted between pre SCS trial anxiety score and high pain score during SCS trial. We conclude that there is potential applicability of a TENS trial as a non invasive screening tool which may promote cost effectiveness and decrease unnecessary procedural risks to the patient by avoiding SCS trial in select patients.

Objectives Many adolescents and young adults report having chronic pain. Urine drug toxicology (UDT) is not routinely used in the pediatric pain management population, despite more routine use in adults with pain, particularly those prescribed opioids. As a first step toward establishing monitoring practices in pediatric and adolescent pain management, the present study evaluated the role of UDT in conjunction with a standard clinical interview in identifying the rate of adherence to an established analgesic regimen. The study also aimed to assess the use of UDT in identifying possible aberrant behaviors in this population. Methods Data were acquired from a convenience sample of 50 pediatric and adolescent pain management initial consultations, during which a clinical interview and UDT were conducted. Data were analyzed to determine adherence to an established analgesic prescription regimen, and for identification of aberrant behaviors including concurrent use of illicit substances and prescription medication misuse. Other pertinent demographic and clinical factors were examined as factors in adherence. Results Opioid medications were prescribed for 42% of the sample receiving pain medications, and 22% of the sample was nonadherent to their prescription analgesic regimen. Factors associated with a higher likelihood of nonadherence were an older age and having an opioid prescription. The majority (90%) of those nonadherent to their analgesic regimen displayed some form of aberrant behavior. Among the nonadherent patients, 50% were identified by UDT alone, and 50% were identified by self-report during the clinical encounter. Conclusions These results highlight the challenges of identifying nonadherence to a prescription regimen among adolescents with chronic pain. In addition, this preliminary work suggests that UDT could be used in conjunction with careful clinical interviewing to substantiate patient report and increase the likelihood of detecting analgesic nonadherence and aberrant behaviors.

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