Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2012 Feb;20(2):330-42.
doi: 10.1038/oby.2011.330. Epub 2011 Nov 3.

Controlled-release Phentermine/Topiramate in Severely Obese Adults: A Randomized Controlled Trial (EQUIP)

Affiliations
Free PMC article
Randomized Controlled Trial

Controlled-release Phentermine/Topiramate in Severely Obese Adults: A Randomized Controlled Trial (EQUIP)

David B Allison et al. Obesity (Silver Spring). .
Free PMC article

Abstract

A 56-week randomized controlled trial was conducted to evaluate safety and efficacy of a controlled-release combination of phentermine and topiramate (PHEN/TPM CR) for weight loss (WL) and metabolic improvements. Men and women with class II and III obesity (BMI ≥ 35 kg/m(2)) were randomized to placebo, PHEN/TPM CR 3.75/23 mg, or PHEN/TPM CR 15/92 mg, added to a reduced-energy diet. Primary end points were percent WL and proportions of patients achieving 5% WL. Secondary end points included waist circumference (WC), systolic and diastolic blood pressure (BP), fasting glucose, and lipid measures. In the primary analysis (randomized patients with at least one postbaseline weight measurement who took at least one dose of assigned drug or placebo), patients in the placebo, 3.75/23, and 15/92 groups lost 1.6%, 5.1%, and 10.9% of baseline body weight (BW), respectively, at 56 weeks (P < 0.0001). In categorical analysis, 17.3% of placebo patients, 44.9% of 3.75/23 patients, and 66.7% of 15/92 patients, lost at least 5% of baseline BW at 56 weeks (P < 0.0001). The 15/92 group had significantly greater changes relative to placebo for WC, systolic and diastolic BP, fasting glucose, triglycerides, total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL). The most common adverse events were paresthesia, dry mouth, constipation, dysgeusia, and insomnia. Dropout rate from the study was 47.1% for placebo patients, 39.0% for 3.75/23 patients, and 33.6% of 15/92 patients. PHEN/TPM CR demonstrated dose-dependent effects on weight and metabolic variables in the direction expected to be beneficial with no evidence of serious adverse events induced by treatment.

Figures

Figure 1
Figure 1
Patient disposition. After screening, all eligible patients underwent 56 weeks of treatment; 4-week blinded, postrandomization titration period, followed by 52 weeks at randomized dose. *Reason for discontinuation as reported while subject was receiving study drug; Reason for study discontinuation. Subjects were able to discontinue study drug and study for different reason, however, reason was often the same. When they differed, the final reason for discontinuation from the study was used. D/C, discontinued; Meds, medications; PHEN/TPM CR, controlled-release phentermine/topiramate.
Figure 2
Figure 2
Plot of efficacy results with analysis A (prespecified ITT-LOCF). (a) Mean percent WL; (b) Patients achieving ≥5%, ≥10%, and ≥15% WL; (c) LS mean percent WL by baseline BMI category. Analysis A included data from patients who discontinued drug but remained in study and continued with data assessments through study completion even though no longer taking drug. The supplementary material presents mean percent WL for Analyses B and C. Error bars represent 95% confidence interval. ITT, intent-to-treat; LOCF, last observation carried forward; LS, least-squares; PHEN/TPM CR, controlled-release phentermine/topiramate; WL, weight loss.

Similar articles

See all similar articles

Cited by 112 articles

See all "Cited by" articles

References

    1. Allison DB, Downey M, Atkinson RL. et al. Obesity as a disease: a white paper on evidence and arguments commissioned by the Council of the Obesity Society Obesity (Silver Spring) 2008161161–1177. - PubMed
    1. Pi-Sunyer FX. A review of long-term studies evaluating the efficacy of weight loss in ameliorating disorders associated with obesity. Clin Ther. 1996;18:1006–35; discussion 1005. - PubMed
    1. Franz MJ, VanWormer JJ, Crain AL. et al. Weight-loss outcomes: a systematic review and meta-analysis of weight-loss clinical trials with a minimum 1-year follow-up J Am Diet Assoc 20071071755–1767. - PubMed
    1. Rothman RB, Baumann MH. Appetite suppressants, cardiac valve disease and combination pharmacotherapy. Am J Ther. 2009;16:354–364. - PMC - PubMed
    1. Wilding J, Van Gaal L, Rissanen A, Vercruysse F, Fitchet M, OBES-002 Study Group A randomized double-blind placebo-controlled study of the long-term efficacy and safety of topiramate in the treatment of obese subjects. Int J Obes Relat Metab Disord. 2004;28:1399–1410. - PubMed

Publication types

MeSH terms

LinkOut - more resources

Feedback