A Pilot Study of S-Adenosylmethionine in Treatment of Functional Abdominal Pain in Children

Context Functional abdominal pain (FAP) is one of the most common functional gastrointestinal disorders (FGIDs) in children. Currently, medical practitioners widely use tricyclic antidepressants to treat PAP. Those antidepressants, however, have been associated with an increased risk of suicidal ideation, and the accompanying side effects often limit the benefits. S-adenosylmethionine (SAM-e) is a dietary supplement that has efficacy as an antidepressant and as a treatment for chronic pain. Objective The research team hypothesized that during SAM-e exposure (1) participants' pain reports would significantly improve over time, (2) participants' reported quality of life would significantly improve over time, and (3) toxicity measures (liver-function tests and mania and depression scales) would not change significantly. Design The research team performed an open-label, doseescalation trial of oral SAM-e among children with FAP. Participants came to the research facility for measurements at baseline and after 2 wk, 1 mo, and 2 mo. The research team monitored participants for potential toxicities (liver toxicity, mania, and depression) throughout the trial. Setting The trial was conducted at the University of California, San Diego. Participants The research team recruited children and adolescents with FAP via advertisement at several community general pediatric clinics and at the research team's subspecialty pediatric gastrointestinal clinic at a tertiary care center. The eight resulting participants were children with a median and mean age of 14 y. Intervention To treat persistent abdominal pain, all participants received SAM-e at an initial dose of 200 mg/d, with escalation to a maximum dose of 1400 mg/d over the period of 2 mo. Outcome Measures The primary outcomes were the participants' self-reports of pain and quality of life. The research team used the multidimensional measure for recurrent abdominal pain (MM-RAP), Wong-Baker FACES Pain Rating Scale, and the PedsQL for those measurements. The team used repeated measures analyses to analyze the data. Results Six participants completed the study. The research team demonstrated an improvement in self-pain reports over the 2-mo follow-up period (P=.004). The median dose of SAM-e that participants took at the 2-mo follow-up period was 1400 mg (interquartile range: 950-1400 mg) daily. Liver function tests and assessments for mania and depression did not change over the study period. Conclusions Oral SAM-e demonstrates promise in reducing abdominal pain among children with PAP, with minimal toxicity. The research team needs to conduct larger, placebo-controlled trials to support its initial findings.