title: Phentermine/topiramate for the treatment of obesity.
abstract: OBJECTIVE
  To review the pharmacology, efficacy, and safety of phentermine/topiramate (PHEN/TPM) in the management of obese patients.
  
  
  METHODS
  MEDLINE (1966-July 2012) was searched using the terms weight loss, obesity, phentermine and topiramate, phentermine, topiramate, Qnexa, Qsymia, and VI-0521. Additionally, the new drug application and prescribing information for PHEN/TPM were retrieved.
  
  
  METHODS
  All studies considering the pharmacology, efficacy, and safety of PHEN/TPM were reviewed with a focus on efficacy and safety data from Phase 3 trials.
  
  
  RESULTS
  In 3 Phase 3 trials (EQUIP, CONQUER, and SEQUEL), treatment with PHEN/TPM consistently demonstrated statistically significant weight loss compared with placebo. After 56 weeks of treatment, percent weight loss achieved with PHEN/TPM was 10.6%, 8.4%, and 5.1% with 15/92 mg, 7.5/46 mg, and 3.75/23 mg, respectively (p < 0.0001). The 52-week extension study (SEQUEL) showed maintained weight loss over 2 years with 9.3% and 10.5% weight loss from baseline for 7.5/46 mg and 15/92 mg PHEN/TPM (p < 0.0001). A significantly higher proportion of patients achieved greater than 5%, 10%, or 15% weight loss with PHEN/TPM compared with placebo. Significant reductions in waist circumference, fasting triglycerides, and fasting glucoses were also attributable to PHEN/TPM. The drug was generally well tolerated in clinical trials. Adverse reactions occurring in 5% or more of study subjects included paresthesia, dizziness, dysgeusia, insomnia, constipation, and dry mouth.
  
  
  CONCLUSIONS
  PHEN/TPM is a new, once-daily, controlled-release, combination weight-loss product approved as an adjunct to diet and exercise for chronic weight management of obese or overweight patients with weight-related comorbidities. PHEN/TPM is modestly effective and a viable option for patients interested in losing weight, although long-term safety data are lacking.
authors.affiliation: Department of Clinical Pharmacy, School of Pharmacy, University of Colorado, Aurora, CO, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Smith
authors.forename: Melissa
authors.initials: M
authors.lastname: Meyer
authors.forename: Katy E
authors.initials: KE
authors.lastname: Trinkley
mesh_terms: D019440:Anti-Obesity Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D004338:Drug Combinations; D005632:Fructose / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D006801:Humans; D009765:Obesity / Q000188:drug therapy*; D010645:Phentermine / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D000077236:Topiramate
chemical_list: D019440:Anti-Obesity Agents; D004338:Drug Combinations; D000077236:Topiramate; D005632:Fructose; D010645:Phentermine