OBJECTIVE: Open trials suggest phentermine/topiramate ER (PHEN/TPM-ER), Food and Drug Administration (FDA) approved for obesity, has utility for binge eating. With no randomized controlled trials (RCTs) yet performed, this trial aimed to evaluate PHEN/TPM-ERs efficacy and safety in a crossover RCT for patients with binge-eating disorder (BED) or bulimia nervosa (BN).METHOD: Participants were randomized to 12-weeks PHEN/TPM-ER (3.75mg/23mg-15mg/92mg) or placebo followed by 2-weeks drug washout, then 12-week crossover. Demographics, vitals, eating disorder behaviors, mood, and side effects were measured. Primary outcome was objective binge-eating (OBE) days/4-weeks; secondary outcomes included binge abstinence. Mixed-effect models estimated treatment effects, with fixed effects adjusting for treatment, study period, and diagnosis.RESULTS: The 22 adults (BED = 18, BN = 4) were female (96%), Caucasian (55%), aged 42.9 (SD = 10.1) years with body mass index = 31.1 (SD = 6.2) kg/m2 . Baseline OBE days/4-weeks decreased from 16.2 (SD = 7.8) to 4.2 (SD = 8.4) after PHEN/TPM-ER versus 13.2 (SD = 9.1) after placebo (p<.0001), with abstinence rates = 63.6% on PHEN/TPM-ER versus 9.1% on placebo (p<.0001). Weight changes = -5.8 kg on PHEN/ TPM-ER versus +0.4 kg on placebo. Drop-out = 2 (9%) on PHEN/TPM-ER and 2 (9%) on placebo, with few side effects. Vital sign changes with PHEN/TPM-ER were minimal and similar to placebo. Responses were not significantly different for BED versus BN.DISCUSSION: This first RCT to evaluate the efficacy and safety of PHEN/TPM-ER for BED/BN found this drug combination significantly more effective at reducing binge eating than placebo and well tolerated. However, with only four participants with BN, findings regarding the safety of PHEN/TPM-ER in patients with BN must be taken with caution.TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT02553824 registered on 9/17/2015. https://clinicaltrials.gov/ct2/show/NCT02553824.
View details for DOI 10.1002/eat.23192
View details for PubMedID 31721257