The potential role of phentermine in the treatment of obesity in the adult population of Mexico.
- 1Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, Mexico.
- 2Laboratorio de Farmacología Clínica y Experimental, Instituto Nacional de Enfermedades Respiratorias, Ismael Cosío Villegas, Mexico City, Mexico.
Abstract
Background
The recently published Mexican guidelines for the management of obesity recommend the alternative use of phentermine for six months or more in adults, based on its low cost and wide availability. However, despite the extensive clinical use of phentermine, accurate information remains limited regarding the clinical appropriateness of selecting a 15 mg versus a 30 mg starting dose, as well as their respective efficacy expectations. This study was aimed to advance these aspects, based in the first month body weight reduction in kilograms (1mo-BWRkg) and month of tolerance development (moT) as efficacy predictors of 15 mg and 30 mg phentermine, on obese Mexicans.Methods
A comparative, prospective, multi-center, uncontrolled phase IV, open-label study was performed in 114 and 151 obese completer subjects treated for 6 months with daily 15 mg and 30 mg phentermine, respectively, between August 2015 and December 2018. Subjects were grouped into various 1mo-BWRkg, moT and 6mo-BWR% (six-month body weight reduction in percentage) intervals. Correlations between 1mo-BWRkg, moT and 1mo-BWRkg + moT with 6mo-BWR% efficacy and a multivariate analysis was performed to determine the impact of these parameters on the 6mo-BWR% efficacy with both phentermine doses.Results
The BWR% profile of 30 mg phentermine was only marginally superior to that of 15 mg phentermine. A large intrasubject variability in BWR% was observed with both interventions. 1mo-BWRkg + moT was found to be an acceptable parameter of 6mo-BWR% for 15 mg and 30 mg phentermine.Conclusion
Our results suggest that once phentermine is selected for initial obesity treatment, starting with a 15 mg dose is a rational approach. An advantage of phentermine is that its 6mo-BWR% effectiveness can be predicted early and progressively. Furthermore, phentermine seems to be a viable long-term alternative to the newer, highly effective, and costly weight-loss drugs for acquisition of healthy lifestyle habits, the improvement of quality of life and life expectancy, and the prevention of health risks in the Mexican population, but requires confirmatory prospective controlled studies.
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BibTeX
@article{villarrealcastellanos2026potential,
title = {{The potential role of phentermine in the treatment of obesity in the adult population of Mexico.}},
author = {Abraham I Villarreal-Castellanos and Héctor I Rocha-González and María E Sánchez-Mendoza and Jesús Arrieta-Valencia and Ana L Pardo-Gutiérrez and Juan Rodríguez-Silverio and Juan C Huerta-Cruz and José E Roa-Coria and Lina M Barranco-Garduño and Juan G Reyes-García},
journal = {Frontiers in medicine},
year = {2026},
month = oct,
doi = {10.3389/fmed.2026.1912418},
url = {https://europepmc.org/article/MED/42922769},
note = {CC BY},
}
RIS
TY - JOUR
TI - The potential role of phentermine in the treatment of obesity in the adult population of Mexico.
AU - Abraham I Villarreal-Castellanos
AU - Héctor I Rocha-González
AU - María E Sánchez-Mendoza
AU - Jesús Arrieta-Valencia
AU - Ana L Pardo-Gutiérrez
AU - Juan Rodríguez-Silverio
AU - Juan C Huerta-Cruz
AU - José E Roa-Coria
AU - Lina M Barranco-Garduño
AU - Juan G Reyes-García
PY - 2026
DA - 2026/10/08
JO - Frontiers in medicine
DO - 10.3389/fmed.2026.1912418
UR - https://europepmc.org/article/MED/42922769
AB - Background The recently published Mexican guidelines for the management of obesity recommend the alternative use of phentermine for six months or more in adults, based on its low cost and wide availability. However, despite the extensive clinical use of phentermine, accurate information remains limited regarding the clinical appropriateness of selecting a 15 mg versus a 30 mg starting dose, as well as their respective efficacy expectations. This study was aimed to advance these aspects, based in the first month body weight reduction in kilograms (1mo-BWRkg) and month of tolerance development (moT) as efficacy predictors of 15 mg and 30 mg phentermine, on obese Mexicans.Methods A comparative, prospective, multi-center, uncontrolled phase IV, open-label study was performed in 114 and 151 obese completer subjects treated for 6 months with daily 15 mg and 30 mg phentermine, respectively, between August 2015 and December 2018. Subjects were grouped into various 1mo-BWRkg, moT and 6mo-BWR% (six-month body weight reduction in percentage) intervals. Correlations between 1mo-BWRkg, moT and 1mo-BWRkg + moT with 6mo-BWR% efficacy and a multivariate analysis was performed to determine the impact of these parameters on the 6mo-BWR% efficacy with both phentermine doses.Results The BWR% profile of 30 mg phentermine was only marginally superior to that of 15 mg phentermine. A large intrasubject variability in BWR% was observed with both interventions. 1mo-BWRkg + moT was found to be an acceptable parameter of 6mo-BWR% for 15 mg and 30 mg phentermine.Conclusion Our results suggest that once phentermine is selected for initial obesity treatment, starting with a 15 mg dose is a rational approach. An advantage of phentermine is that its 6mo-BWR% effectiveness can be predicted early and progressively. Furthermore, phentermine seems to be a viable long-term alternative to the newer, highly effective, and costly weight-loss drugs for acquisition of healthy lifestyle habits, the improvement of quality of life and life expectancy, and the prevention of health risks in the Mexican population, but requires confirmatory prospective controlled studies.
SN - 2296-858X
ER -