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1.
Lancet ; 403(10434): e21-e31, 2024 04 06.
Article in English | MEDLINE | ID: mdl-38582569

ABSTRACT

BACKGROUND: Pharmacotherapy provides an option for adults with overweight and obesity to reduce their bodyweight if lifestyle modifications fail. We summarised the latest evidence for the benefits and harms of weight-lowering drugs. METHODS: This systematic review and network meta-analysis included searches of PubMed, Embase, and Cochrane Library (CENTRAL) from inception to March 23, 2021, for randomised controlled trials of weight-lowering drugs in adults with overweight and obesity. We performed frequentist random-effect network meta-analyses to summarise the evidence and applied the Grading of Recommendations Assessment, Development, and Evaluation frameworks to rate the certainty of evidence, calculate the absolute effects, categorise interventions, and present the findings. The study was registered with PROSPERO, CRD 42021245678. FINDINGS: 14 605 citations were identified by our search, of which 132 eligible trials enrolled 48 209 participants. All drugs lowered bodyweight compared with lifestyle modification alone; all subsequent numbers refer to comparisons with lifestyle modification. High to moderate certainty evidence established phentermine-topiramate as the most effective in lowering weight (odds ratio [OR] of ≥5% weight reduction 8·02, 95% CI 5·24 to 12·27; mean difference [MD] of percentage bodyweight change -7·98, 95% CI -9·27 to -6·69) followed by GLP-1 receptor agonists (OR 6·33, 95% CI 5·00 to 8·00; MD -5·79, 95% CI -6·34 to -5·25). Naltrexone-bupropion (OR 2·69, 95% CI 2·10 to 3·44), phentermine-topiramate (2·40, 1·68 to 3·44), GLP-1 receptor agonists (2·22, 1·74 to 2·84), and orlistat (1·71, 1·42 to 2·05) were associated with increased adverse events leading to drug discontinuation. In a post-hoc analysis, semaglutide, a GLP-1 receptor agonist, showed substantially larger benefits than other drugs with a similar risk of adverse events as other drugs for both likelihood of weight loss of 5% or more (OR 9·82, 95% CI 7·09 to 13·61) and percentage bodyweight change (MD -11·40, 95% CI -12·51 to -10·29). INTERPRETATION: In adults with overweight and obesity, phentermine-topiramate and GLP-1 receptor agonists proved the best drugs in reducing weight; of the GLP-1 agonists, semaglutide might be the most effective. FUNDING: 1.3.5 Project for Disciplines of Excellence, West China Hospital, Sichuan University.


Subject(s)
Obesity , Overweight , Adult , Humans , Overweight/drug therapy , Network Meta-Analysis , Topiramate/therapeutic use , Obesity/drug therapy , Weight Loss , Phentermine/adverse effects , Randomized Controlled Trials as Topic
2.
Int J Clin Pharmacol Ther ; 62(10): 435-447, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39045734

ABSTRACT

BACKGROUND: Obesity is a complex disease for which pharmacotherapy is often used. Anti-obesity drugs (AODs) are characterized by inducing a variable inter-subject body weight reduction (BWR), the attainment of a plateau after their maximal effect is achieved, and weight regain after drug discontinuation, which complicate individualized treatment of obesity. OBJECTIVE: This exploratory analysis aimed to compare the first-month body weight reduction in kg (1mo-BWRkg) and tolerance development (moT) of four known interventions with low (placebo), intermediate (phentermine or mazindol monotherapy), and high (5 active ingredients fixed-dose combination) efficacy, as predictors of their 6-month body weight reduction efficacy in percent (6mo-BWR%). In addition, a detailed analysis of the 6-to-12-month BWR follow-up in subjects under orlistat or diet and exercise regimens was performed. MATERIALS AND METHODS: The analysis included 662 adult subjects with obesity. After the construction of average efficacy and weight rebound curves, subjects were grouped into various 1mo-BWRkg, moT, and 6mo-BWR% intervals, or 6-month body weight rebound parameters for further evaluation. RESULTS: The 6mo-BWR% efficacy level of interventions was confirmed, although a general high intersubject variation was observed. 1mo-BWRkg + moT was found as an acceptable predictor of 6mo-BWR%. Between 50 and 80% of the 6-to-12-month follow-up completers maintained at least 5% BWR%. CONCLUSION: Short-term AODs are useful adjuvants for the 1-year rational treatment of obesity. 1mo-BWRkg + moT is an acceptable parameter to predict the 6mo-BWR% efficacy of these interventions.


Subject(s)
Anti-Obesity Agents , Obesity , Weight Loss , Humans , Obesity/drug therapy , Anti-Obesity Agents/therapeutic use , Adult , Female , Weight Loss/drug effects , Male , Middle Aged , Treatment Outcome , Time Factors , Phentermine/therapeutic use , Phentermine/adverse effects
3.
Ann Intern Med ; 176(4): 443-454, 2023 04.
Article in English | MEDLINE | ID: mdl-36940443

ABSTRACT

BACKGROUND: The U.S. Food and Drug Administration approved phentermine-topiramate for obesity in 2012 and required a Risk Evaluation and Mitigation Strategy (REMS) to prevent prenatal exposure. No such requirement was introduced for topiramate. OBJECTIVE: To evaluate the rate of prenatal exposure, contraceptive use, and pregnancy testing among patients with phentermine-topiramate compared with topiramate or other antiobesity medications (AOMs). DESIGN: Retrospective cohort study. SETTING: Nationwide health insurance claims database. PARTICIPANTS: Females aged 12 to 55 years with no infertility diagnosis or sterilization procedure. Patients with other indications for topiramate were excluded to identify a cohort that was likely treated for obesity. MEASUREMENTS: Patients initiated use of phentermine-topiramate, topiramate, or an AOM (liraglutide, lorcaserin, or bupropion-naltrexone). Pregnancy at treatment initiation, conception during treatment, contraceptive use, and pregnancy testing outcomes were ascertained. Measurable confounders were adjusted for, and extensive sensitivity analyses were done. RESULTS: A total of 156 280 treatment episodes were observed. Adjusted prevalence of pregnancy at treatment initiation was 0.9 versus 1.6 per 1000 episodes (prevalence ratio, 0.54 [95% CI, 0.31 to 0.95]) for phentermine-topiramate versus topiramate. The incidence rate of conception during treatment was 9.1 versus 15.0 per 1000 person-years (rate ratio, 0.61 [CI, 0.40 to 0.91]) for phentermine-topiramate versus topiramate. Both outcomes were similarly lower for phentermine-topiramate compared with AOM. Prenatal exposure was marginally lower in topiramate users compared with AOM users. Approximately 20% of patients in all cohorts had at least 50% of treatment days covered by contraceptives. Few patients had pregnancy tests before treatment (≤5%), but this was more common among phentermine-topiramate users. LIMITATIONS: Outcome misclassification; unmeasured confounding due to lack of prescriber data to account for possible clustering and spillover effects. CONCLUSION: Prenatal exposure seemed to be significantly lower among phentermine-topiramate users under the REMS. Pregnancy testing and contraceptive use appeared to be inadequate for all groups, which deserves attention to prevent the remaining potential exposures. PRIMARY FUNDING SOURCE: None.


Subject(s)
Anti-Obesity Agents , Prenatal Exposure Delayed Effects , Female , Humans , Pregnancy , Topiramate/therapeutic use , Phentermine/adverse effects , Retrospective Studies , Risk Evaluation and Mitigation , Weight Loss , Obesity/chemically induced , Anti-Obesity Agents/adverse effects , Contraceptive Agents/therapeutic use , Fructose/adverse effects
4.
JAMA ; 332(7): 571-584, 2024 08 20.
Article in English | MEDLINE | ID: mdl-39037780

ABSTRACT

Importance: Obesity affects approximately 19% of women and 14% of men worldwide and is associated with increased morbidity. Antiobesity medications (AOMs) modify biological processes that affect appetite and significantly improve outcomes, such as type 2 diabetes, hypertension, and dyslipidemia. Observations: AOMs should be administered in combination with lifestyle interventions and can be classified according to their mechanisms of action. Orlistat modifies digestive tract absorption and causes gastrointestinal adverse effects, such as oily fecal spotting and urgency, in more than 25% of patients. Centrally acting drugs, such as phentermine-topiramate and naltrexone-bupropion, regulate appetite in the brain and are associated with constipation in approximately 20% of patients, although the incidence of other adverse effects (eg, paresthesia, nausea) varies by medication. Nutrient-stimulated hormone-based medications, such as liraglutide, semaglutide, and tirzepatide, mimic the actions of enteropancreatic hormones that modify central appetite regulation and provide multiple cardiometabolic weight-loss benefits. Adverse effects of these drugs include nausea (28%-44%), diarrhea (21%-30%), and constipation (11%-24%). The relative potency of adult obesity medications has been studied in meta-analyses. Compared with placebo, orlistat was associated with 3.1% greater weight loss (52 randomized clinical trials [RCTs]; 16 964 participants), phentermine-topiramate was associated with 8.0% greater weight loss (5 RCTs; 3407 participants), naltrexone-bupropion was associated with 4.1% greater weight loss (6 RCTs; 9949 participants), liraglutide was associated with 4.7% greater weight loss (18 RCTs; 6321 participants), semaglutide was associated with 11.4% greater weight loss (5 RCTs; 4421 participants), and tirzepatide 15 mg was associated with 12.4% greater weight loss (6 RCTs; 1972 participants). Conclusion and Relevance: Obesity is associated with increased morbidity. Antiobesity medications are effective adjunctive therapy to lifestyle changes for improved weight loss and health outcomes.


Subject(s)
Anti-Obesity Agents , Diet, Healthy , Obesity , Female , Humans , Male , Anti-Obesity Agents/therapeutic use , Anti-Obesity Agents/adverse effects , Bupropion/therapeutic use , Bupropion/adverse effects , Drug Combinations , Fructose/analogs & derivatives , Fructose/therapeutic use , Fructose/adverse effects , Glucagon-Like Peptides/therapeutic use , Glucagon-Like Peptides/adverse effects , Lactones/therapeutic use , Lactones/adverse effects , Liraglutide/therapeutic use , Liraglutide/adverse effects , Naltrexone/therapeutic use , Naltrexone/adverse effects , Obesity/diet therapy , Obesity/drug therapy , Orlistat/therapeutic use , Phentermine/therapeutic use , Phentermine/adverse effects , Topiramate/therapeutic use , Topiramate/adverse effects , Weight Loss/drug effects , Combined Modality Therapy/methods
5.
Hepatology ; 73(5): 2051-2062, 2021 05.
Article in English | MEDLINE | ID: mdl-33047343

ABSTRACT

BACKGROUND AND AIMS: Thirty percent of patients with cirrhosis are obese and the prevalence of obesity increases after transplant to >40% post-transplant. There are currently four weight loss medications approved by the FDA for treatment of obesity (orlistat, phentermine-topiramate, naltrexone-bupropion, and liraglutide). The aim of this review was to investigate the data on the use of these weight loss medications and alternative medicines in patients with cirrhosis and in liver transplant recipients (LTRs). APPROACH AND RESULTS: While there is paucity of data for these medications in patients with cirrhosis and LTRs, Liraglutide appears to be generally safe in view of its pharmacokinetic properties. Phentermine-topiramate seems to have the highest weight loss potential but special consideration should be given to neuropsychiatric disorders, cardiovascular comorbidities, and drug interactions. There are emerging data on use of alternative medicines for weight loss but more data are needed. CONCLUSIONS: The use of weight loss medications is feasible in this patient population but the decision of which medication to prescribe should be individualized based on the degree of renal and hepatic impairment, other co-morbidities, and concomitant medications.


Subject(s)
Anti-Obesity Agents/therapeutic use , Liver Cirrhosis/complications , Liver Transplantation/adverse effects , Obesity/complications , Bupropion/administration & dosage , Bupropion/adverse effects , Bupropion/therapeutic use , Drug Therapy, Combination , Humans , Liraglutide/adverse effects , Liraglutide/therapeutic use , Liver Transplantation/methods , Naltrexone/administration & dosage , Naltrexone/adverse effects , Naltrexone/therapeutic use , Obesity/drug therapy , Orlistat/adverse effects , Orlistat/therapeutic use , Phentermine/administration & dosage , Phentermine/adverse effects , Phentermine/therapeutic use , Topiramate/administration & dosage , Topiramate/adverse effects , Topiramate/therapeutic use , Translational Science, Biomedical
6.
Med Princ Pract ; 31(3): 254-261, 2022.
Article in English | MEDLINE | ID: mdl-35526530

ABSTRACT

OBJECTIVE: Hepatic steatosis is associated with increased surgical complications in bariatric surgery patients. We aimed to evaluate the effect of phentermine in reducing hepatic steatosis, adipose tissue, and surgical complications in patients undergoing bariatric surgery. METHODS: This was a two-arm, double-blind, randomized, controlled pilot trial of 64 adult subjects with BMI >35 kg/m2 selected for bariatric surgery randomized into phentermine group (15 mg once daily) or placebo group for 8 weeks. Both groups adhered to a hypocaloric diet (500 calories/day) and an individualized exercise program. The primary endpoint was reducing the frequency of hepatic steatosis measured by ultrasound and reducing adipose tissue through fat mass in total kilograms or percentage. Key secondary points were the prevalence of surgical complications. Baseline and final biochemical parameters and blood pressure too were assessments. RESULTS: In the phentermine group, the frequency of hepatic steatosis decreased by 19%, and the percentage of patients with a normal ultrasound increased from 9% to 28% (p = 0.05). Likewise, the decrease in fat mass in kilograms was more significant in the phentermine group (56.1 kg vs. 51.8 kg, p = 0.02). A significant reduction in the HOMA-IR index was observed regardless of weight loss. No differences in surgical complications were observed between groups. Phentermine was well-tolerated; no differences were observed in the frequency of adverse events between the groups. CONCLUSIONS: Phentermine decreased the proportion of individuals with hepatic steatosis by 19% and promoted a more significant fat mass loss in kilograms among candidates for bariatric surgery.


Subject(s)
Bariatric Surgery , Phentermine , Adult , Bariatric Surgery/adverse effects , Diet, Reducing , Humans , Obesity/complications , Obesity/surgery , Phentermine/adverse effects , Phentermine/therapeutic use , Pilot Projects
7.
Cochrane Database Syst Rev ; 1: CD007654, 2021 01 17.
Article in English | MEDLINE | ID: mdl-33454957

ABSTRACT

BACKGROUND: This is the third update of this review, first published in July 2009. All major guidelines on treatment of hypertension recommend weight loss; anti-obesity drugs may be able to help in this respect. OBJECTIVES: Primary objectives: To assess the long-term effects of pharmacologically-induced reduction in body weight in adults with essential hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events).. Secondary objectives: To assess the long-term effects of pharmacologically-induced reduction in body weight in adults with essential hypertension on change from baseline in systolic and diastolic blood pressure, and on body weight reduction. SEARCH METHODS: For this updated review, the Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to March 2020: the Cochrane Hypertension Specialised Register, CENTRAL, MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. The searches had no language restrictions. We contacted authors of relevant papers about further published and unpublished work. SELECTION CRITERIA: Randomised controlled trials of at least 24 weeks' duration in adults with hypertension that compared approved long-term weight-loss medications to placebo.  DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risks of bias, and extracted data. Where appropriate and in the absence of significant heterogeneity between studies (P > 0.1), we pooled studies using a fixed-effect meta-analysis. When heterogeneity was present, we used the random-effects method and investigated the cause of the heterogeneity. MAIN RESULTS: This third update of the review added one new trial, investigating the combination of naltrexone/bupropion versus placebo. Two medications, which were included in the previous versions of this review (rimonabant and sibutramine) are no longer considered relevant for this update, since their marketing approval was withdrawn in 2010 and 2009, respectively. The number of included studies in this review update is therefore six (12,724 participants in total): four RCTs comparing orlistat to placebo, involving a total of 3132 participants with high blood pressure and a mean age of 46 to 55 years; one trial comparing phentermine/topiramate to placebo, involving 1305 participants with high blood pressure and a mean age of 53 years; and one trial comparing naltrexone/bupropion to placebo, involving 8283 participants with hypertension and a mean age of 62 years. We judged the risks of bias to be unclear for the trials investigating orlistat or naltrexone/bupropion. and low for the trial investigating phentermine/topiramate. Only the study of naltrexone/bupropion included cardiovascular mortality and morbidity as predefined outcomes. There were no differences in the rates of all-cause or cardiovascular mortality, major cardiovascular events, or serious adverse events between naltrexone/bupropion and placebo. The incidence of overall adverse events was significantly higher in participants treated with naltrexone/bupropion. For orlistat, the incidence of gastrointestinal side effects was consistently higher compared to placebo. The most frequent side effects with phentermine/topiramate were dry mouth and paraesthesia. After six to 12 months, orlistat reduced systolic blood pressure compared to placebo by mean difference (MD) -2.6 mm Hg (95% confidence interval (CI) -3.8 to -1.4 mm Hg; 4 trials, 2058 participants) and diastolic blood pressure by MD -2.0 mm Hg (95% CI -2.7 to -1.2 mm Hg; 4 trials, 2058 participants). After 13 months of follow-up, phentermine/topiramate decreased systolic blood pressure compared to placebo by -2.0 to -4.2 mm Hg (1 trial, 1030 participants) (depending on drug dosage), and diastolic blood pressure by -1.3 to -1.9 mm Hg (1 trial, 1030 participants) (depending on drug dosage). There was no difference in the change in systolic or diastolic blood pressure between naltrexone/bupropion and placebo (1 trial, 8283 participants). We identified no relevant studies investigating liraglutide or lorcaserin in people with hypertension. AUTHORS' CONCLUSIONS: In people with elevated blood pressure, orlistat, phentermine/topiramate and naltrexone/bupropion reduced body weight; the magnitude of the effect was greatest with phentermine/topiramate. In the same trials, orlistat and phentermine/topiramate, but not naltrexone/bupropion, reduced blood pressure. One RCT of naltrexone/bupropion versus placebo showed no differences in all-cause mortality or cardiovascular mortality or morbidity after two years. The European Medicines Agency refused marketing authorisation for phentermine/topiramate due to safety concerns, while for lorcaserin the application for European marketing authorisation was withdrawn due to a negative overall benefit/risk balance. In 2020 lorcaserin was also withdrawn from the US market. Two other medications (rimonabant and sibutramine) had already been withdrawn from the market in 2009 and 2010, respectively.


Subject(s)
Anti-Obesity Agents/adverse effects , Appetite Depressants/adverse effects , Hypertension/drug therapy , Adult , Anti-Obesity Agents/therapeutic use , Appetite Depressants/therapeutic use , Bias , Blood Pressure/drug effects , Body Weight/drug effects , Bupropion/adverse effects , Bupropion/therapeutic use , Diet, Reducing , Drug Combinations , Female , Fructose/adverse effects , Fructose/analogs & derivatives , Fructose/therapeutic use , Humans , Hypertension/mortality , Lactones/adverse effects , Lactones/therapeutic use , Male , Middle Aged , Naltrexone/adverse effects , Naltrexone/therapeutic use , Orlistat/adverse effects , Orlistat/therapeutic use , Phentermine/adverse effects , Phentermine/therapeutic use , Piperidines/adverse effects , Piperidines/therapeutic use , Pyrazoles/adverse effects , Pyrazoles/therapeutic use , Randomized Controlled Trials as Topic , Safety-Based Drug Withdrawals , Time , Topiramate/adverse effects , Topiramate/therapeutic use
8.
Int J Clin Pharmacol Ther ; 59(8): 539-548, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34236303

ABSTRACT

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.


Subject(s)
Anti-Obesity Agents , Appetite Depressants , Adult , Anti-Obesity Agents/adverse effects , Humans , Mexico , Obesity/drug therapy , Phentermine/adverse effects , Prospective Studies
9.
Int J Obes (Lond) ; 44(5): 1021-1027, 2020 05.
Article in English | MEDLINE | ID: mdl-32152496

ABSTRACT

AIMS: Over the past several decades, many antiobesity drugs have been withdrawn from the market due to unanticipated adverse events, often involving cardiotoxicity. This study aimed to evaluate the presence of cardiovascular safety signals with currently marketed antiobesity drugs. METHODS: We used the US Food and Drug Administration Adverse Event Reporting System (FAERS) database and retrieved data from January 2013 through December 2018. We performed disproportionality analyses to detect cardiovascular safety signals with three antiobesity drugs recently approved for marketing: lorcaserin, naltrexone-bupropion, phentermine, and phentermine-topiramate. Three main cardiovascular outcomes were evaluated: valvular disorders, and pulmonary hypertension (PH) and other cardiovascular events (myocardial infarction, stroke, cardiovascular death, cardiac failure, and arrhythmia). RESULTS: During the evaluated period, a total of 6,787,840 adverse event reports were submitted to FAERS. Of these, 2687 involved lorcaserin, 3960 involved phentermine/phentermine-topiramate, and 2873 involved naltrexone-bupropion. Lorcaserin was associated with a significantly greater proportion of reports of valvular disorders (ROR = 4.39; 95% CI 2.72-5.07). None of the antiobesity drugs were associated with a safety signal for valvulopathy, PH, or other cardiovascular events. CONCLUSIONS: Our analyses revealed a signal for valvular disorders with lorcaserin and did not detect a safety signal for other cardiovascular events with recently approved antiobesity drugs. Further research is needed to explore and validate this signal.


Subject(s)
Anti-Obesity Agents/adverse effects , Cardiovascular Diseases , Drug-Related Side Effects and Adverse Reactions/epidemiology , Adult , Adverse Drug Reaction Reporting Systems , Aged , Anti-Obesity Agents/therapeutic use , Benzazepines/adverse effects , Benzazepines/therapeutic use , Cardiovascular Diseases/chemically induced , Cardiovascular Diseases/epidemiology , Databases, Factual , Female , Humans , Male , Middle Aged , Naltrexone/adverse effects , Naltrexone/therapeutic use , Obesity/drug therapy , Phentermine/adverse effects , Phentermine/therapeutic use , United States , United States Food and Drug Administration
10.
Diabetes Obes Metab ; 22(4): 480-491, 2020 04.
Article in English | MEDLINE | ID: mdl-31696603

ABSTRACT

AIMS: To assess the pharmacokinetic (PK) and pharmacodynamic characteristics of VI-0521, a fixed-dose combination of immediate-release phentermine (PHEN) and extended-release topiramate (TPM) in adolescents aged 12 to 17 years with obesity, and to report weight loss and adverse events using this drug combination. MATERIALS AND METHODS: This was a multicentre, randomized, double-blind, parallel-design, placebo-controlled study in adolescents with obesity. A total of 42 adolescents were randomly assigned in a 1:1:1 ratio to placebo, or to a mid-dose (PHEN/TPM 7.5 mg/46 mg), or a top-dose (PHEN/TPM 15 mg/92 mg) of VI-0521. A total of 26 adolescents were included in the PK analysis (14 from the mid-dose group and 12 from the top-dose group). RESULTS: On day 56, arithmetic means of terminal elimination half-life, apparent clearance (CL/F) and apparent central volume of distribution (Vc/F) were consistent across dose levels for both PHEN and TPM. Arithmetic means of CL/F and Vc/F for PHEN and TPM administered as a combination in adolescents with obesity were within 10% to 30% of those previously assessed in adults with obesity enrolled in phase II and III studies. A higher proportion of adolescents in both the mid- and top-dose groups (13.3% and 50.0%, respectively) compared with placebo (0.0%) reached ≥5% weight loss at day 56. The least squares (LS) mean change in systolic blood pressure from baseline to day 56 was -5.2 mmHg for the placebo group, -2.5 mmHg for the mid-dose group, and - 5.5 mmHg for the top-dose group. The LS mean change in diastolic blood pressure from baseline to day 56 was -2.4 mmHg for the placebo group, +3.8 mmHg for the mid-dose group, and + 2.0 mmHg for the top-dose group. Participants in the top-dose group had increases in heart rate from baseline of 4.1 bpm, while participants in the mid-dose group experienced a mean decrease in heart rate of 4.5 bpm at day 56. Both PHEN/TPM dose combinations were safe and well tolerated. CONCLUSIONS: Treatment of adolescents with obesity using a fixed-dose combination of PHEN/TPM for 8 weeks resulted in exposure to PHEN and TPM that was comparable to that observed in adults, statistically significant weight loss, and a tolerable safety profile. These data indicate that both mid- and top-dose levels are appropriate for longer-term safety and efficacy studies in adolescents.


Subject(s)
Anti-Obesity Agents , Adolescent , Anti-Obesity Agents/adverse effects , Child , Double-Blind Method , Fructose/adverse effects , Humans , Obesity/complications , Obesity/drug therapy , Phentermine/adverse effects , Topiramate
11.
Endocr Pract ; 26(9): 990-996, 2020 Sep.
Article in English | MEDLINE | ID: mdl-33471704

ABSTRACT

OBJECTIVE: Obesity is a well-known risk factor for infertility. However, the use of weight loss medications prior to conception is underutilized. The objectives of our study are to describe weight loss, pregnancy rates, and live birth rates after short-term phentermine use in women with obesity and infertility. METHODS: This was a retrospective analysis of 55 women (18 to 45 years old) who were overweight or obese, diagnosed with infertility, and prescribed phentermine for weight loss in an ambulatory endocrinology clinic at a single, tertiary level academic medical center. Main outcome measures were mean percent weight change at 3 months after starting phentermine, and pregnancy, and live birth rates from start of phentermine to June 30, 2017. RESULTS: Median duration of phentermine use was 70 days (Q1, Q3 [33, 129]). Mean ± SD percent weight change at 3 months after starting phentermine was -5.3 ± 4.1% (P<.001). The pregnancy rate was 60% and the live birth rate was 49%. There was no significant difference in pregnancy rates (52% versus 68%; P = .23) or live birth rates (44% versus 54%; P = .50) in women who lost ≥5% versus <5% of their baseline weight. The number of metabolic comorbidities was negatively associated with the pregnancy rate. Phentermine was generally well-tolerated with no serious adverse events. CONCLUSION: Phentermine can produce clinically significant weight loss in women with obesity during the preconception period. Higher pregnancy or live birth rates were not observed with a greater degree of weight loss with phentermine.


Subject(s)
Anti-Obesity Agents , Weight Loss , Adolescent , Adult , Female , Humans , Middle Aged , Phentermine/adverse effects , Pregnancy , Pregnancy Outcome/epidemiology , Retrospective Studies , Young Adult
13.
Ann Plast Surg ; 81(4): 503-507, 2018 10.
Article in English | MEDLINE | ID: mdl-30204622

ABSTRACT

PURPOSE: Phentermine is the most prescribed antiobesity drug in America, with 2.43 million prescriptions written in 2011. Case reports suggest there are anesthetic risks, such as refractory hypotension, involved with its perioperative use. Despite these risks and the frequency of phentermine use among plastic surgery patients, there are no published guidelines for the perioperative management of phentermine use in the plastic surgery literature. To address this patient safety issue, we performed a systematic review and provide management recommendations. METHODS: A systematic review of the pharmacology of phentermine and the anesthetic risks involved with its perioperative use was undertaken using the search engines PubMed/MEDLINE, EMBASE, and Scopus. RESULTS: A total of 251 citations were reviewed, yielding 4 articles that discussed perioperative phentermine use and complications with anesthesia. One was a review article, 2 were case reports, and 1 was a letter. Complications included hypotension, hypertension, hypoglycemia, hyperthermia, bradycardia, cardiac depression, and acute pulmonary edema. CONCLUSIONS: The relationship between phentermine and anesthesia, if any, is unclear. Hypotension on induction of general anesthesia is the most reported complication of perioperative phentermine use. Specifically, phentermine-induced hypotension may be unresponsive to vasopressors that rely on catecholamine release, such as ephedrine. Therefore, the decision to perform surgery, especially elective surgery, in a patient taking phentermine should be made with caution. Because of the half-life of phentermine, we recommend discontinuing phentermine for at least 4 days prior to surgery. This differs from the classic 2-week discontinuation period recommended for "fen-phen." The patient should be made aware of the increased risk of surgery, and a skilled anesthesiologist should monitor intraoperative blood pressure and body temperature for signs of autonomic derailment.


Subject(s)
Anesthesia , Anesthetics/pharmacology , Appetite Depressants/pharmacology , Phentermine/pharmacology , Plastic Surgery Procedures , Anesthetics/adverse effects , Appetite Depressants/adverse effects , Drug Interactions , Humans , Phentermine/adverse effects
14.
Aust Fam Physician ; 46(7): 472-477, 2017.
Article in English | MEDLINE | ID: mdl-28697290

ABSTRACT

BACKGROUND: Obesity is a serious, chronic, relapsing disease of energy regulation, with strong genetic and early-life environmental determinants. Pharmacotherapy can be a useful adjunct to lifestyle intervention in effecting and maintaining clinically meaningful weight loss. OBJECTIVE: The aim of this article is to discuss the role of pharmacotherapy in obesity management. The efficacy, side effects and contraindications of available weight-loss medications are reviewed. DISCUSSION: Long-term pharmacotherapy options, which can be effective in providing moderate weight loss, are available to treat obesity. Pharma-cotherapy should be considered an adjunct to lifestyle intervention in those with a body mass index (BMI) >30 kg/m30 kg/m2, or in those with a BMI of 27-30 kg/m2 and obesity-related complications. Safety and efficacy should be monitored closely on commencement, and the medication should be discontinued if there are safety or tolerability issues, or if.


Subject(s)
Drug Therapy/methods , Drug Therapy/standards , Obesity/drug therapy , Anti-Obesity Agents/adverse effects , Anti-Obesity Agents/pharmacology , Anti-Obesity Agents/therapeutic use , Appetite Depressants/adverse effects , Appetite Depressants/pharmacology , Appetite Depressants/therapeutic use , Body Mass Index , Drug Therapy, Combination/adverse effects , Drug Therapy, Combination/standards , Fructose/adverse effects , Fructose/analogs & derivatives , Fructose/pharmacology , Fructose/therapeutic use , Humans , Incretins/adverse effects , Incretins/pharmacology , Incretins/therapeutic use , Lactones/adverse effects , Lactones/pharmacology , Lactones/therapeutic use , Liraglutide/adverse effects , Liraglutide/pharmacology , Liraglutide/therapeutic use , Orlistat , Phentermine/adverse effects , Phentermine/pharmacology , Phentermine/therapeutic use , Topiramate
15.
Cochrane Database Syst Rev ; 3: CD007654, 2016 Mar 02.
Article in English | MEDLINE | ID: mdl-26934640

ABSTRACT

BACKGROUND: All major guidelines on antihypertensive therapy recommend weight loss; anti-obesity drugs may be able to help in this respect. PRIMARY OBJECTIVES: To assess the long-term effects of pharmacologically induced reduction in body weight in adults with essential hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events). SECONDARY OBJECTIVES: To assess the long-term effects of pharmacologically induced reduction in body weight in adults with essential hypertension on change from baseline in systolic blood pressure, change from baseline in diastolic blood pressure, and body weight reduction. SEARCH METHODS: We obtained studies using computerised searches of the Cochrane Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid EMBASE, the clinical trials registry ClinicalTrials.gov, and from handsearches in reference lists and systematic reviews (status as of 13 April 2015). SELECTION CRITERIA: Randomised controlled trials in hypertensive adults of at least 24 weeks' duration that compared long-term pharmacologic interventions for weight loss with placebo.  DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risk of bias, and extracted data. Where appropriate and in the absence of significant heterogeneity between studies (P > 0.1), we pooled studies using fixed-effect meta-analysis. When heterogeneity was present, we used the random-effects method and investigated the cause of heterogeneity. MAIN RESULTS: After updating the literature search, which was extended to include four new weight-reducing drugs, we identified one additional study of phentermine/topiramate, bringing the total number of studies to nine that compare orlistat, sibutramine, or phentermine/topiramate to placebo and thus fulfil our inclusion criteria. We identified no relevant studies investigating rimonabant, liraglutide, lorcaserin, or naltrexone/bupropion. No study included mortality and cardiovascular morbidity as predefined outcomes. Incidence of gastrointestinal side effects was consistently higher in those participants treated with orlistat versus those treated with placebo. The most frequent side effects were dry mouth, constipation, and headache with sibutramine, and dry mouth and paresthaesia with phentermine/topiramate. In participants assigned to orlistat, sibutramine, or phentermine/topiramate body weight was reduced more effectively than in participants in the usual-care/placebo groups. Orlistat reduced systolic blood pressure as compared to placebo by -2.5 mm Hg (mean difference (MD); 95% confidence interval (CI): -4.0 to -0.9 mm Hg) and diastolic blood pressure by -1.9 mm Hg (MD; 95% CI: -3.0 to -0.9 mm Hg). Sibutramine increased diastolic blood pressure compared to placebo by +3.2 mm Hg (MD; 95% CI: +1.4 to +4.9 mm Hg). The one trial that investigated phentermine/topiramate suggested it lowered blood pressure. AUTHORS' CONCLUSIONS: In people with elevated blood pressure, orlistat and sibutramine reduced body weight to a similar degree, while phentermine/topiramate reduced body weight to a greater extent. In the same trials, orlistat and phentermine/topiramate reduced blood pressure, while sibutramine increased it. We could include no trials investigating rimonabant, liraglutide, lorcaserin, or naltrexone/bupropion in people with elevated blood pressure. Long-term trials assessing the effect of orlistat, liraglutide, lorcaserin, phentermine/topiramate, or naltrexone/bupropion on mortality and morbidity are unavailable and needed. Rimonabant and sibutramine have been withdrawn from the market, after long-term trials on mortality and morbidity have confirmed concerns about the potential severe side effects of these two drugs. The European Medicines Agency refused marketing authorisation for phentermine/topiramate due to safety concerns, while the application for European marketing authorisation for lorcaserin was withdrawn by the manufacturer after the Committee for Medicinal Products for Human Use judged the overall benefit/risk balance to be negative.


Subject(s)
Anti-Obesity Agents/adverse effects , Appetite Depressants/adverse effects , Hypertension/drug therapy , Weight Loss , Adult , Anti-Obesity Agents/therapeutic use , Appetite Depressants/therapeutic use , Blood Pressure/drug effects , Cyclobutanes/adverse effects , Cyclobutanes/therapeutic use , Diet, Reducing , Female , Fructose/adverse effects , Fructose/analogs & derivatives , Fructose/therapeutic use , Humans , Hypertension/mortality , Lactones/adverse effects , Lactones/therapeutic use , Male , Middle Aged , Orlistat , Phentermine/adverse effects , Phentermine/therapeutic use , Piperidines/adverse effects , Piperidines/therapeutic use , Pyrazoles/adverse effects , Pyrazoles/therapeutic use , Randomized Controlled Trials as Topic , Rimonabant , Safety-Based Drug Withdrawals , Time , Topiramate
16.
Clin Auton Res ; 26(3): 229-33, 2016 06.
Article in English | MEDLINE | ID: mdl-26968177

ABSTRACT

Stimulant medication may mimic the tachycardia of postural orthostatic tachycardia syndrome. Two case histories illustrate how missing the clinical distinction between a primary dysautonomia and a medication effect may have avoidable adverse consequences.


Subject(s)
Phentermine/adverse effects , Postural Orthostatic Tachycardia Syndrome/diagnosis , Adult , Central Nervous System Stimulants/adverse effects , Central Nervous System Stimulants/pharmacology , Diagnostic Errors , Female , Heart Rate/drug effects , Humans , Norepinephrine Plasma Membrane Transport Proteins/antagonists & inhibitors , Obesity , Postural Orthostatic Tachycardia Syndrome/chemically induced , Tilt-Table Test
17.
JAMA ; 315(22): 2424-34, 2016 Jun 14.
Article in English | MEDLINE | ID: mdl-27299618

ABSTRACT

IMPORTANCE: Five medications have been approved for the management of obesity, but data on comparative effectiveness are limited. OBJECTIVE: To compare weight loss and adverse events among drug treatments for obesity using a systematic review and network meta-analysis. DATA SOURCES: MEDLINE, EMBASE, Web of Science, Scopus, and Cochrane Central from inception to March 23, 2016; clinical trial registries. STUDY SELECTION: Randomized clinical trials conducted among overweight and obese adults treated with US Food and Drug Administration-approved long-term weight loss agents (orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, or liraglutide) for at least 1 year compared with another active agent or placebo. DATA EXTRACTION AND SYNTHESIS: Two investigators identified studies and independently abstracted data using a predefined protocol. A Bayesian network meta-analysis was performed and relative ranking of agents was assessed using surface under the cumulative ranking (SUCRA) probabilities. Quality of evidence was assessed using GRADE criteria. MAIN OUTCOMES AND MEASURES: Proportions of patients with at least 5% weight loss and at least 10% weight loss, magnitude of decrease in weight, and discontinuation of therapy because of adverse events at 1 year. RESULTS: Twenty-eight randomized clinical trials with 29 018 patients (median age, 46 years; 74% women; median baseline body weight, 100.5 kg; median baseline body mass index, 36.1) were included. A median 23% of placebo participants had at least 5% weight loss vs 75% of participants taking phentermine-topiramate (odds ratio [OR], 9.22; 95% credible interval [CrI], 6.63-12.85; SUCRA, 0.95), 63% of participants taking liraglutide (OR, 5.54; 95% CrI, 4.16-7.78; SUCRA, 0.83), 55% taking naltrexone-bupropion (OR, 3.96; 95% CrI, 3.03-5.11; SUCRA, 0.60), 49% taking lorcaserin (OR, 3.10; 95% CrI, 2.38-4.05; SUCRA, 0.39), and 44% taking orlistat (OR, 2.70; 95% CrI, 2.34-3.09; SUCRA, 0.22). All active agents were associated with significant excess weight loss compared with placebo at 1 year-phentermine-topiramate, 8.8 kg (95% CrI, -10.20 to -7.42 kg); liraglutide, 5.3 kg (95% CrI, -6.06 to -4.52 kg); naltrexone-bupropion, 5.0 kg (95% CrI, -5.94 to -3.96 kg); lorcaserin, 3.2 kg (95% CrI, -3.97 to -2.46 kg); and orlistat, 2.6 kg (95% CrI, -3.04 to -2.16 kg). Compared with placebo, liraglutide (OR, 2.95; 95% CrI, 2.11-4.23) and naltrexone-bupropion (OR, 2.64; 95% CrI, 2.10-3.35) were associated with the highest odds of adverse event-related treatment discontinuation. High attrition rates (30%-45% in all trials) were associated with lower confidence in estimates. CONCLUSIONS AND RELEVANCE: Among overweight or obese adults, orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, and liraglutide, compared with placebo, were each associated with achieving at least 5% weight loss at 52 weeks. Phentermine-topiramate and liraglutide were associated with the highest odds of achieving at least 5% weight loss.


Subject(s)
Anti-Obesity Agents/adverse effects , Obesity/drug therapy , Weight Loss , Anti-Obesity Agents/therapeutic use , Bayes Theorem , Benzazepines/adverse effects , Benzazepines/therapeutic use , Drug Combinations , Female , Fructose/adverse effects , Fructose/analogs & derivatives , Fructose/therapeutic use , Humans , Lactones/adverse effects , Lactones/therapeutic use , Liraglutide/adverse effects , Liraglutide/therapeutic use , Male , Middle Aged , Naltrexone/adverse effects , Naltrexone/therapeutic use , Orlistat , Phentermine/adverse effects , Phentermine/therapeutic use , Randomized Controlled Trials as Topic , Topiramate
18.
Conn Med ; 80(4): 213-5, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27265924

ABSTRACT

Weight-loss medications have been associated with many conditions, including valvular heart disease, ischemic colitis, and pulmonary hypertension. There is a constant increase in the use of these drugs, especially new medications with better efficacy. Phentermine is one such drug, approved for short-term use to lose weight. We report a case of ischemic colitis in a female patient linked to inappropriate phentermine intake. The patient presented with symptoms of severe abdominal pain and repeated bowel movement associated with rectal bleeding for two weeks. Initial blood work was unremarkable for infectious and inflammatory causes. A CT scan was performed which revealed findings of ischemic colitis extending from transverse to descending colon. A biopsy study confirmed the same. Upon further questioning, the patient admitted to taking 37.5 mg of phentermine for two years beyond her prescribed period of 12 weeks. Hence, we propose that inappropriate use of phentermine caused ischemic colitis. With the widespread use of these medications, there is a need for heightened awareness among clinicians regarding adverse effects of phentermine.


Subject(s)
Appetite Depressants/adverse effects , Colitis, Ischemic/chemically induced , Phentermine/adverse effects , Adult , Colitis, Ischemic/pathology , Colonoscopy , Drug Administration Schedule , Female , Humans
19.
J Neurophysiol ; 114(1): 585-607, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25972577

ABSTRACT

Obesity is a worldwide health problem that has reached epidemic proportions. To ameliorate this problem, one approach is the use of appetite suppressants. These compounds are frequently amphetamine congeners such as diethylpropion (DEP), phentermine (PHEN), and bupropion (BUP), whose effects are mediated through serotonin, norepinephrine, and dopaminergic pathways. The nucleus accumbens (NAc) shell receives dopaminergic inputs and is involved in feeding and motor activity. However, little is known about how appetite suppressants modulate its activity. Therefore, we characterized behavioral and neuronal NAc shell responses to short-term treatments of DEP, PHEN, and BUP. These compounds caused a transient decrease in weight and food intake while increasing locomotion, stereotypy, and insomnia. They evoked a large inhibitory imbalance in NAc shell spiking activity that correlated with the onset of locomotion and stereotypy. Analysis of the local field potentials (LFPs) showed that all three drugs modulated beta, theta, and delta oscillations. These oscillations do not reflect an aversive-malaise brain state, as ascertained from taste aversion experiments, but tracked both the initial decrease in weight and food intake and the subsequent tolerance to these drugs. Importantly, the appetite suppressant-induced weight loss and locomotion were markedly reduced by intragastric (and intra-NAc shell) infusions of dopamine antagonists SCH-23390 (D1 receptor) or raclopride (D2 receptor). Furthermore, both antagonists attenuated appetite suppressant-induced LFP oscillations and partially restored the imbalance in NAc shell activity. These data reveal that appetite suppressant-induced behavioral and neuronal activity recorded in the NAc shell depend, to various extents, on dopaminergic activation and thus point to an important role for D1/D2-like receptors (in the NAc shell) in the mechanism of action for these anorexic compounds.


Subject(s)
Appetite Depressants/pharmacology , Dopamine D2 Receptor Antagonists/pharmacology , Nucleus Accumbens/drug effects , Receptors, Dopamine D1/antagonists & inhibitors , Action Potentials/drug effects , Action Potentials/physiology , Animals , Appetite Depressants/adverse effects , Benzazepines/pharmacology , Bupropion/adverse effects , Bupropion/pharmacology , Diethylpropion/adverse effects , Diethylpropion/pharmacology , Drug Interactions , Eating/drug effects , Eating/physiology , Locomotion/drug effects , Locomotion/physiology , Male , Nucleus Accumbens/physiology , Phentermine/adverse effects , Phentermine/pharmacology , Raclopride/pharmacology , Random Allocation , Rats, Sprague-Dawley , Receptors, Dopamine D1/metabolism , Receptors, Dopamine D2/metabolism , Sleep Initiation and Maintenance Disorders/chemically induced , Stereotyped Behavior/drug effects , Stereotyped Behavior/physiology , Weight Loss/drug effects , Weight Loss/physiology
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