Journal of Obesity & Metabolic Syndrome



Korean J Obes 2005; 14(1): 1-8

Published online January 1, 2005

Copyright © Korean Society for the Study of Obesity.

Efficacy and Safety of Phentermine for Obese Patients : A Preliminary Open-Label Study

Park Yong-Woo

Department of Family Medicine, Sungkyunkwan University School of Medicine


Background: Phentermine, an anti-obesity drug which has been used for more than 40 years in the United States, was recently introduced in Korea. There is no article about phentermine for Korean people. This is a preliminary open-label study to reveal the efficacy and the safety of phentermine for Korean obese patients.
Methods: Sixty-three subjects (24 men, 39 women) were selected among obese (body mass index ≥ 25 kg/m2) patients who visited the obesity clinic of a university hospital during August 16th ~ October 15th, 2004. Phentermine (Phentermine hydrochloride 37.5 mg) was administered for 12 weeks. The efficacy was evaluated by the differences of body weight, waist circumference, and % body fat between baseline and after 12-week medications.
Results: Fifteen subjects were dropped out and 10 subjects stopped medications during the study period. Among thirty-eight subjects who kept taking medications, 34 subjects (89.5%) had more than 5% weight loss, and 21 subjects (55.3%) had more than 10% weight loss compared with baseline weights. Thirty-two subjects (50.8%) complained of 47 adverse reactions, which were dry mouth (23.8%), constipation (12.7%), excessive sweating (7.9%), headache (4.8%), abdominal discomfort (4.8%), nausea (3.2%), palpitation (3.2%), insomnia (3.2%), dizziness (3.2%), urinary hesitancy (3.2%) etc. Ten subjects stopped medications due to adverse reactions (7 subjects), no effects (2 subjects), and pregnancy (1 subject). Serious adverse reactions or complications were not found.
Conclusion: Phentermine showed 11% weight loss in obese subjects with 12-week administration. Fiftyone % of subjects showed adverse reactions, but serious reactions were not found.

Keywords: Phentermine, Efficacy, Safety