Pyridostigmine and low-dose naltrexone for ME/CFS: study protocol for the Life Improvement Trial (LIFT), a randomized, double-blind, placebo-controlled clinical trial

Background Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, chronic disease with no FDA-approved treatments. This report describes a protocol for the Life Improvement Trial (LIFT), a randomized, double-blind, placebo-controlled clinical trial investigating the impact of low-dose naltrexone (LDN) and pyridostigmine (Mestinon) on physiological response, symptoms, and functionality of ME/CFS patients. Methods Participants (target n = 160) are recruited through clinics at Massachusetts General Hospital and Brigham and Women’s Hospital, and through Open Medicine Foundation’s StudyME registry. They are then randomized into one of four arms: LDN/pyridostigmine, LDN/placebo, placebo/pyridostigmine, placebo/placebo. Treatment is administered for 13 weeks after an initial screening period of up to 4 weeks. Primary outcomes are FUNCAP-55 score, peak oxygen utilization, heart rate recovery, and oxygen uptake efficiency slope. Secondary outcomes are scores from DSQ-PEM and PROMIS-29 surveys, DANA Brain Vital score, step count, heart rate, and heart rate variability. Discussion The results of this trial will provide novel insights into the efficacy of and predictors of response to LDN and pyridostigmine in ME/CFS. This may inform future treatment strategies for ME/CFS. The trial will also validate what primary and secondary outcomes to use in similar clinical trials. Trial registration: This trial was registered on clinicaltrials.gov (NCT06366724) on April 16, 2024.