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International Journal of Clinical... Aug 2021Mexico has the second largest prevalence of obesity among adults worldwide, a condition especially affecting the low-income population. There is a pressing need to... (Clinical Trial)
Clinical Trial
OBJECTIVE
Mexico has the second largest prevalence of obesity among adults worldwide, a condition especially affecting the low-income population. There is a pressing need to improve therapeutic options for weight loss. Phentermine is an old and low-cost agent given as an adjuvant therapy for obesity for a 12-week period, at an initial dose of 15 mg or 30 mg. However, there are no precise guidelines on the suitability of both the starting dose and the continuation of treatment for 6 months. The aim of this study was to evaluate the 3- and 6-month efficacy and safety of phentermine in obese Mexican patients to elucidate the aforementioned.
MATERIALS AND METHODS
In this prospective, multi-center, open-label study, 932 obese adults received 15 mg or 30 mg phentermine once daily for 6 months.
RESULTS
30 mg phentermine was more effective than 15 mg phentermine in improving anthropometric variables in the 3-month follow-up, but not after completing the 6-month treatment period. Nearly 40% of 3-month non-responders reached a body weight reduction of at least 5% at 6 months. Conversely, ~ 65% and 25% of 3-month responders maintained or improved, respectively, their body weight reduction with long-term phentermine. Potential tolerance as weight regain was ~ 10% from 3 to 6 months. None of the doses increased cardiovascular risk, although mild-to-moderate adverse events were more frequent with 30 mg phentermine.
CONCLUSION
30 mg phentermine was more effective than 15 mg phentermine after 3 months, but not at 6 months of treatment. An important number of subjects could benefit following the therapy from 3 to 6 months.
Topics: Adult; Anti-Obesity Agents; Appetite Depressants; Humans; Mexico; Obesity; Phentermine; Prospective Studies
PubMed: 34236303
DOI: 10.5414/CP203943 -
Journal of Drugs in Dermatology : JDD Nov 2020
Topics: Adult; Amlodipine; Appetite Depressants; Biopsy; Drug Administration Schedule; Drug Therapy, Combination; Female; Hand; Humans; Mycophenolic Acid; Overweight; Phentermine; Scleroderma, Diffuse; Skin; Time Factors
PubMed: 33196751
DOI: 10.36849/JDD.2020.5663 -
Metabolism: Clinical and Experimental Jul 2019This pilot study evaluated whether adding phentermine to liraglutide would induce further weight loss in participants who had previously lost weight with liraglutide... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
This pilot study evaluated whether adding phentermine to liraglutide would induce further weight loss in participants who had previously lost weight with liraglutide alone.
SUBJECTS/METHODS
Participants were 45 adults with obesity (75.6% female, 55.6% white, body mass index = 34.3 ± 4.7 kg/m) who had lost an average of 12.6 ± 6.8% of initial weight during a prior 1-year randomized trial with liraglutide and intensive behavioral treatment. Participants were re-randomized, in a double-blinded fashion, to liraglutide 3.0 mg plus phentermine 15.0 mg (liraglutide-phentermine) or liraglutide plus placebo (liraglutide-placebo). Participants also were provided with four, 15-minute counseling sessions during the 12-week extension study.
RESULTS
At week 12, the liraglutide-phentermine and liraglutide-placebo groups lost a mean (±SEM) of 1.6 ± 0.6% and 0.1 ± 0.5% of re-randomization weight, respectively (p = 0.073). Two (9.1%) liraglutide-phentermine participants and one (4.3%) liraglutide-placebo participant lost ≥5% of re-randomization weight; 19 (86.4%) and 16 (69.9%) participants, respectively, maintained their full weight loss achieved in the prior 1-year trial (p = 0.125). Liraglutide-phentermine participants generally reported larger reductions in hunger and food preoccupation than liraglutide-placebo participants during the first 8 weeks of the extension study.
CONCLUSIONS
The combination of liraglutide and phentermine appeared to be well-tolerated but did not produce additional clinically meaningful weight loss in individuals who had already lost 12.6% of initial weight with liraglutide alone.
TRIAL REGISTRATION
ClinicalTrials.gov number, NCT02911818.
Topics: Adult; Aged; Anti-Obesity Agents; Appetite; Appetite Depressants; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Hunger; Liraglutide; Male; Middle Aged; Obesity; Phentermine; Pilot Projects; Treatment Outcome; Weight Loss
PubMed: 30902750
DOI: 10.1016/j.metabol.2019.03.005 -
Archives of Internal Medicine Nov 1997
Topics: Humans; Obesity; Phentermine; Resins, Plant; Salts
PubMed: 9361582
DOI: No ID Found -
Prescrire International Mar 2013The cornerstones of treatment for obesity, and even more so for simple overweight, are dietary measures and physical exercise. There are no drugs with a favourable...
The cornerstones of treatment for obesity, and even more so for simple overweight, are dietary measures and physical exercise. There are no drugs with a favourable harm-benefit balance in this setting. A fixed-dose combination of topiramate, an antiepileptic drug, and phentermine, an appetite-suppressant amphetamine, has been refused marketing authorisation in the European Union, after being licensed in the United States. There are no randomised controlled trials of topiramate + phentermine in the prevention of complications of obesity. In the three available placebo-controlled trials, patients treated with topiramate 46 mg per day + phentermine 7.5 mg per day for between 1 and 2 years lost about 6-8 kg more than patients who received a placebo. About one-quarter of this weight loss was regained within a year after treatment discontinuation. The known adverse effects of the two drugs composing this combination are additive, and include psychiatric disorders, cardiac arrhythmias and metabolic acidosis. The risk of serious cardiovascular disorders was not adequately studied during clinical trials. Many women of child-bearing age would be exposed to this combination, which can provoke fetal abnormalities, including cleft palate, if taken during pregnancy. In practice, the topiramate + phentermine combination has an unfavourable harm-benefit balance and has no place in the treatment of obesity.
Topics: Anti-Obesity Agents; Appetite Depressants; Drug Approval; Drug Combinations; European Union; Female; Fructose; Humans; Obesity; Overweight; Phentermine; Pregnancy; Topiramate; United States
PubMed: 23593686
DOI: No ID Found -
Biochemical Pharmacology Mar 2002Recent studies with rat tissue preparations have suggested that the anorectic drug phentermine inhibits serotonin degradation by inhibition of monoamine oxidase (MAO) A...
Recent studies with rat tissue preparations have suggested that the anorectic drug phentermine inhibits serotonin degradation by inhibition of monoamine oxidase (MAO) A with a K(I) value of 85-88 microM, a potency suggested to be similar to that of other reversible MAO inhibitors (Ulus et al., Biochem Pharmacol 2000;59:1611-21). Since there are known differences between rats and humans in substrate and inhibitor specificities of MAOs, the interactions of phentermine with recombinant human purified preparations of MAO A and MAO B were determined. Human MAO A was competitively inhibited by phentermine with a K(I) value of 498+/-60 microM, a value approximately 6-fold weaker than that observed for the rat enzyme. Phentermine was also observed to be a competitive inhibitor of recombinant human liver MAO B with a K(I) value of 375+/-42 microM, a value similar to that observed with the rat enzyme (310-416 microM). In contrast to the behavior with rat tissue preparations, no slow time-dependent behavior was observed for phentermine inhibition of purified soluble human MAO preparations. Difference absorption spectral studies showed similar perturbations of the covalent FAD moieties of both human MAO A and MAO B, which suggests a similar mode of binding in both enzymes. These data suggest that phentermine inhibition of human MAO A (or of MAO B) is too weak to be of pharmacological relevance.
Topics: Appetite Depressants; Humans; Liver; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Phentermine; Recombinant Proteins; Saccharomyces cerevisiae; Spectrophotometry, Atomic
PubMed: 11911838
DOI: 10.1016/s0006-2952(02)00840-7 -
South African Medical Journal =... Aug 1976
Topics: Diabetes Mellitus; Humans; Obesity; Phentermine; Placebos
PubMed: 968682
DOI: No ID Found -
Obesity (Silver Spring, Md.) Jun 2020Weight regain (WR) after Roux-en-Y gastric bypass surgery (RYGB) starts to occur 2 years after surgery, ultimately affecting at least 25% of patients. A limited number...
OBJECTIVE
Weight regain (WR) after Roux-en-Y gastric bypass surgery (RYGB) starts to occur 2 years after surgery, ultimately affecting at least 25% of patients. A limited number of studies have evaluated the impact of antiobesity medications (AOMs) on this phenomenon.
METHODS
This study reviewed the electronic medical records of 1,196 patients who underwent RYGB between 2004 and 2015. WR was evaluated by comparing each patient's weight during subsequent postoperative office visits to nadir weight (lowest weight after RYGB, n = 760), taking into consideration the interval during which WR occurred. Patients who were prescribed AOMs and came to follow-up visits were classified as adherent users, whereas those who missed their follow-up visits were considered nonadherent. This study used a linear mixed model, Cox regression, and generalized equation estimator to determine the impact of AOMs on WR trajectory, hazard ratio for time to event, and odds ratio for repeated event occurrence, respectively.
RESULTS
Despite the lack of a unified protocol for using AOMs, the three statistical models converged to show that phentermine and topiramate, used individually or in combination, can significantly reduce WR after RYGB.
CONCLUSIONS
Phentermine and topiramate are effective in mitigating WR after RYGB. Further studies are needed to help ascertain optimal use of AOMs after bariatric surgery.
Topics: Adult; Anti-Obesity Agents; Female; Gastric Bypass; Humans; Male; Middle Aged; Phentermine; Postoperative Period; Retrospective Studies; Topiramate; Weight Gain
PubMed: 32441476
DOI: 10.1002/oby.22786 -
Evaluation of phentermine and fenfluramine, alone and in combination, in normal, healthy volunteers.Neuropsychopharmacology : Official... Apr 1996Recent clinical reports indicate that combined administration of phentermine and fenfluramine may have useful effects in the treatment of drug abuse. The present study... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
Recent clinical reports indicate that combined administration of phentermine and fenfluramine may have useful effects in the treatment of drug abuse. The present study was designed to evaluate the subjective and mood-altering effects of these drugs, alone and in combination, in normal healthy volunteers. Seven male and five female volunteers participated in an eight-session, double-blind study in which each subject received each of the following drug conditions: d-amphetamine (10 and 20 mg), phentermine (30 mg), fenfluramine (40 and 80 mg), phentermine (30 mg) with fenfluramine (40 mg), phentermine (30 mg) with fenfluramine (80 mg), and placebo. Sessions were conducted in a laboratory setting two or three days a week. Subjects completed standardized self-report questionnaires and psychomotor tests before and at regular intervals after each drug administration. Phentermine produced effects that were similar to those of d-amphetamine, whereas fenfluramine produced different and apparently aversive effects (e.g., it increased measures of anxiety and confusion). Phentermine reduced the apparently aversive effects of fenfluramine when the two drugs were given together. These results suggest that the combination of phentermine and fenfluramine would have a low potential for abuse.
Topics: Adult; Drug Therapy, Combination; Female; Fenfluramine; Humans; Male; Phentermine; Reference Values
PubMed: 8924191
DOI: 10.1016/0893-133X(95)00113-R -
Toxicology and Applied Pharmacology Mar 1961
Topics: Butylamines; Humans; Phentermine; Sympathomimetics
PubMed: 13688436
DOI: 10.1016/s0041-008x(61)80010-0