Effects of genotype and food on naltrexone exposure in adolescents

Naltrexone (NTX), an opioid antagonist metabolized by aldo-keto reductase 1C4 (AKR1C4), is prescribed for psychiatric conditions like eating disorders with variable response. Systemic exposure is highly variable in adults, yet no data exist in children. The purpose of this study was to evaluate NTX exposure in adolescents with eating disorders. Adolescents aged 12-21 years with eating disorders underwent postdose blood sampling in the fasted and/or fed state. NTX and primary active metabolite, 6-β-naltrexol, were determined by ultra-high performance liquid chromatography tandem mass spectrometry. Pharmacokinetic parameters were determined by noncompartmental analysis. DNA was genotyped for AKR1C4 missense mutations associated with decreased activity (rs3829125 and rs17134592). Linear mixed effects modeling was performed. In 21 participants, aged 16.9 ± 1.9 years (15-21 years), 81% female participants, maximum concentration (C_max ) was 90.4 ± 129 nM/mg/kg, area under the concentration-time curve from zero to infinity (AUC_0-∞ ) was 166 ± 154 nM h/mg/kg, and varied 63-fold and 21-fold, respectively. Compared with wildtype, those with AKR1C4 allelic variations (n = 7) displayed 3.2-fold higher AUC_0-∞ , four-fold higher C_max and delayed time to T_max . Linear mixed effects modeling demonstrated a large effect of genotype on AUC_0-∞ (Cohen's d -2.3) and C_max (Cohen's d -1.4). Food effect was large for AUC_0-∞ (Cohen's d 2.6), but highly variable and failed to reach significance for C_max. The respective model accounted for 82% of the variance in NTX AUC_0-∞ and 46% of the variance in C_max . NTX systemic exposure is highly variable in adolescents with eating disorders and modulated, in part, by AKR1C4 genotype and food intake. These findings may, in part, explain the large degree of interindividual variability observed response to NTX.

Naltrexone Reduces Binge Eating and Purging in Adolescents in an Eating Disorder Program

Objective: Little evidence exists for pharmacologic treatment of binge eating and purging in adolescents with eating disorders. Given the role of the opioid reward system in compulsive binge eating and purging, naltrexone, an opioid antagonist, may be effective in reducing these behaviors. Previous studies have demonstrated that naltrexone reduces binge eating and purging in adults, yet evidence for its use in adolescents is lacking. This case series describes naltrexone utilization, response, and safety in adolescents with eating disorders. Methods: A retrospective chart review of adolescent patients prescribed naltrexone at an academic eating disorder program was completed. Results: Thirty-three adolescents aged 15.3 ± 1.49 years, 94% female gender identity, were treated with naltrexone with the most common expected outcome "to reduce vomiting." Naltrexone was prescribed for 129 ± 125 days. Over half of patients (52%, n = 17) had liver function tests during follow-up, all of which were within normal limits. Three patients (9.1%) experienced nausea related to naltrexone. Just over half of adolescents (67%; n = 22) had documentation of positive naltrexone response (e.g., reduced purging or urge to purge). The mean Clinical Global Impressions-Improvement score was 2.7 ± 1.3 (2 = much improved; 3 = minimally improved). Conclusions: Naltrexone is safe, well tolerated, and effective for the treatment of adolescents with binge eating and/or purging as part of a comprehensive eating disorder treatment plan. Further study is necessary to confirm the effectiveness of naltrexone prospectively and evaluate factors contributing to naltrexone response vs. nonresponse to promote an individualized approach to treatment of binge eating and purging behavior.

Sexual and Reproductive Health Care Services in the Pediatric Setting

Pediatricians are an important source of health care for adolescents and young adults and can play a significant role in addressing their patients' sexual and reproductive health needs, including preventing unintended pregnancies and sexually transmitted infections (STIs), including HIV, and promoting healthy relationships. STIs, HIV, and unintended pregnancy are all preventable health outcomes with potentially serious permanent sequelae; the highest rates of STIs, HIV, and unintended pregnancy are reported among adolescents and young adults. Office visits present opportunities to provide comprehensive education and health care services to adolescents and young adults to prevent STIs, HIV, and unintended pregnancies. The American Academy of Pediatrics, other professional medical organizations, and the government have guidelines and recommendations regarding the provision of sexual and reproductive health information and services. However, despite these recommendations, recent studies have revealed that there is substantial room for improvement in actually delivering the recommended services. The purpose of this clinical report is to assist pediatricians to operationalize the provision of various aspects of sexual and reproductive health care into their practices and to provide guidance on overcoming barriers to providing this care routinely while maximizing opportunities for confidential health services delivery in their offices.

Methodological issues in measuring treatment outcome in adolescent smoking cessation studies

As the prevalence of adolescent smoking and, notably, regular smoking has increased over the last decade, researchers and practitioners have called for a consideration of treatment programs to promote cessation among adolescents who smoke. The adolescent smoking cessation treatment field is still in its infancy, though. The literature addressing adolescent cessation is rather limited to date, often plagued by methodological problems and characterized by little success. Many basic methodological questions remain for researchers to address before we will be able to answer questions such as which treatment approaches work best for which adolescent smokers. The purpose of this paper is to review briefly what is known about adolescent smoking cessation, to identify some important methodological issues to consider in treatment outcome studies, and to make recommendations to researchers to help provide a common ground for future comparisons of results across studies. We will address the natural history of adolescent smoking cessation, treatment outcomes, validity of self-reports and biochemical validation, and research recommendations.