MedPath

Phentermine

Generic Name
Phentermine
Brand Names
Adipex-P, Lomaira, Qsymia
Drug Type
Small Molecule
Chemical Formula
C10H15N
CAS Number
122-09-8
Unique Ingredient Identifier
C045TQL4WP
Background

Phentermine is a sympathomimetic amine anorectic agent and it was introduced in 1959 as part of an anti-obesity combination drug. It is chemically related to amphetamine and it is commonly referred to as an atypical amphetamine. Phentermine has not been reported an addictive potential which allows this agent to be classified under the Schedule IV drugs (low abuse potential).

Phentermine was FDA approved for short-term weight management in 1959 and it became widely used in 1960. This initial product, formed by the combination of phentermine with fenfluramine and dexfenfluramine was discontinued after finding several reports of abnormal valves in nearly 30% of the consumers. Later on, phentermine was approved alone and in combination with topiramate in 2012 as a new alternative that required lower doses of phentermine to obtain the desired effect.

Indication

Phentermine is indicated, alone or in combination with topiramate, as a short-term adjunct, not pass a few weeks, in a regimen of weight reduction based on exercise, behavioral modifications and caloric restriction in the management of exogenous obesity for patients with an initial body mass index (BMI) greater than 30 kg/m2 or greater than 27 kg/m2 in presence of other risk factors such as controller hypertension, diabetes or hyperlipidemia.

Exogenous obesity is considered when the overweight is caused by consuming more food than the person activity level warrants. This condition commonly causes an increase in fat storage. It is an epidemic condition in the United States where over two-thirds of adults are overweight or obese and one in three Americans is obese. In the world, the incidence of obesity has nearly doubled.

Associated Conditions
Obesity
Associated Therapies
Chronic Weight Management therapy

Efficacy and Safety of Phentermine/Topiramate in Youth with Hypothalamic Obesity

Phase 2
Recruiting
Conditions
Hypothalamic Obesity
Hypothalamic Tumor
Craniopharyngioma
Interventions
First Posted Date
2024-03-08
Last Posted Date
2025-02-10
Lead Sponsor
Seattle Children's Hospital
Target Recruit Count
24
Registration Number
NCT06299891
Locations
🇺🇸

Seattle Children's, Seattle, Washington, United States

🇺🇸

The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

Pharmacotherapy in Conjunction With Lifestyle Counseling for Management of Weight Regain After Bariatric Surgery

Phase 4
Recruiting
Conditions
Obesity
Interventions
First Posted Date
2023-08-04
Last Posted Date
2025-01-15
Lead Sponsor
University of California, Irvine
Target Recruit Count
120
Registration Number
NCT05975580
Locations
🇺🇸

University of California Irvine Medical Center, Orange, California, United States

Anti-obesity Pharmacotherapy and Inflammation

Active, not recruiting
Conditions
Obesity
Interventions
First Posted Date
2023-03-06
Last Posted Date
2025-01-10
Lead Sponsor
Louisiana State University Health Sciences Center in New Orleans
Target Recruit Count
30
Registration Number
NCT05756764
Locations
🇺🇸

LSU Clinical & Translational Research Center (CTRC - - LSUHSC-NO, New Orleans, Louisiana, United States

🇺🇸

Ochsner Health System - Biospecimen, New Orleans, Louisiana, United States

A Study of VI-0521 on Ambulatory Blood Pressure (ABPM) in Overweight or Obese Subjects

Phase 4
Completed
Conditions
Blood Pressure
Interventions
First Posted Date
2022-01-31
Last Posted Date
2024-07-17
Lead Sponsor
VIVUS LLC
Target Recruit Count
565
Registration Number
NCT05215418
Locations
🇺🇸

Clinical Site, Norfolk, Virginia, United States

🇺🇸

Clinical site, Salt Lake City, Utah, United States

Long-term Effectiveness of the Antiobesity Medication Phentermine

Phase 4
Active, not recruiting
Conditions
Lifestyle, Healthy
Obesity
Obesity; Drug
Interventions
Behavioral: Online Lifestyle Behavioral Therapy
First Posted Date
2022-01-04
Last Posted Date
2025-04-25
Lead Sponsor
Wake Forest University Health Sciences
Target Recruit Count
870
Registration Number
NCT05176626
Locations
🇺🇸

Kaiser Permanente Southern California, Los Angeles, California, United States

🇺🇸

HealthPartners Institute, Saint Louis Park, Minnesota, United States

🇺🇸

Atrium Health Wake Forest Baptist Weight Management Center, Winston-Salem, North Carolina, United States

and more 1 locations

Obesity and Uric Acid Stones Study

Phase 3
Completed
Conditions
Obesity
Type 2 Diabetes Mellitus in Obese
Pre-Diabetes
Uric Acid Stones
Interventions
Combination Product: Citrate Salts, Allopurinol, Diet
First Posted Date
2020-11-09
Last Posted Date
2025-03-30
Lead Sponsor
University of Florida
Target Recruit Count
22
Registration Number
NCT04621929
Locations
🇺🇸

University of Florida, Gainesville, Florida, United States

Comparing a Virtual vs. Face to Face Weight Management Program Using Phentermine for Patients With Overweight or Obesity

Phase 4
Completed
Conditions
Obesity
Interventions
Behavioral: Dietary program
Behavioral: Exercise program
First Posted Date
2020-11-04
Last Posted Date
2022-12-07
Lead Sponsor
The Cleveland Clinic
Target Recruit Count
70
Registration Number
NCT04614545
Locations
🇺🇸

Cleveland Clinic, Cleveland, Ohio, United States

Medications After Adolescent Bariatric Surgery

Phase 2
Withdrawn
Conditions
Pediatric Obesity
Interventions
First Posted Date
2020-10-01
Last Posted Date
2022-05-26
Lead Sponsor
Janey Pratt
Registration Number
NCT04572217
Locations
🇺🇸

Stanford University, Palo Alto, California, United States

EMI-EHP Weight Management and Type 2 Diabetes Pragmatic Trial

Phase 4
Terminated
Conditions
Type 2 Diabetes
Obesity
Interventions
Other: Weight Management Program (WMP)
Other: Traditional care
Drug: naltrexone/bupropion extended-release
First Posted Date
2020-08-28
Last Posted Date
2024-07-22
Lead Sponsor
The Cleveland Clinic
Target Recruit Count
74
Registration Number
NCT04531176
Locations
🇺🇸

Cleveland Clinic, Cleveland, Ohio, United States

Adjunct Phentermine + Topiramate After Bariatric Surgery in 12-24 Year Olds

Phase 2
Completed
Conditions
Bariatric Surgery
Young Adult
Obesity, Morbid
Adolescent
Drug Therapy
Interventions
First Posted Date
2019-09-19
Last Posted Date
2022-03-09
Lead Sponsor
Jaime Moore, MD MPH
Target Recruit Count
13
Registration Number
NCT04095104
Locations
🇺🇸

Children's Hospital Colorado, Aurora, Colorado, United States

© Copyright 2025. All Rights Reserved by MedPath