Retrospective Evaluation of Sibutramine-Topiramate Therapy for Obesity in Real-World Outpatient Practice (SIBUTAMATE)

This retrospective real-world cohort study aims to evaluate the effectiveness, safety, and tolerability of the combination of sibutramine and topiramate in the treatment of obesity and overweight associated with metabolic comorbidities in adult patients treated in an outpatient clinical setting. Obesity is a chronic, multifactorial, and progressive disease associated with substantial metabolic, cardiovascular, and psychosocial burden. Although newer anti-obesity therapies such as GLP-1 receptor agonists and dual agonists have demonstrated high efficacy, their elevated cost significantly limits accessibility in low- and middle-income populations and restricts widespread implementation in routine clinical practice. Consequently, there is an increasing need for affordable, accessible, and clinically effective pharmacological strategies for obesity management.

Sibutramine is a serotonin and norepinephrine reuptake inhibitor that promotes appetite suppression and increased satiety, while topiramate is a neuromodulatory agent with anorexigenic effects mediated through GABAergic and glutamatergic pathways. The pharmacological combination of these agents has been increasingly used in clinical practice because of their complementary mechanisms of action and relatively low cost. Previous studies and observational data have suggested meaningful weight reduction and acceptable tolerability with this combination under appropriate medical supervision.

The present study is designed as a retrospective observational cohort based on the review of medical records from adult patients treated between January 2023 and December 2025 at a private outpatient clinic in Brazil. Eligible participants include adults aged 18 years or older with obesity (body mass index [BMI] ≥30 kg/m²) or overweight (BMI ≥27 kg/m²) associated with at least one metabolic comorbidity, including type 2 diabetes mellitus, prediabetes, dyslipidemia, or hypertension. Patients must have received concomitant treatment with sibutramine and topiramate for a minimum period of three months and have documented clinical follow-up with at least two consultations containing anthropometric and clinical information.

Patients with pregnancy, breastfeeding, uncontrolled hypertension, significant cardiovascular disease, severe psychiatric disorders, epilepsy, nephrolithiasis, glaucoma, severe renal or hepatic disease, or concomitant use of medications known to significantly interfere with body weight will be excluded. Records lacking sufficient anthropometric or clinical follow-up information will also be excluded from analysis.

Data extracted from medical records will include demographic variables, baseline body weight, BMI, treatment duration, medication doses, percentage weight change over time, adherence to follow-up, eating behavior control, and adverse events reported during treatment. All information will be anonymized before analysis. No identifiable personal information, including names, telephone numbers, addresses, or identification numbers, will be collected. Data will be stored in password-protected electronic databases accessible only to the principal investigator.

The primary outcome is the percentage change in body weight and BMI during treatment with the sibutramine-topiramate combination. Secondary outcomes include the proportion of patients achieving clinically significant weight loss thresholds (≥5%, ≥10%, and ≥15%), early treatment response defined as ≥3% body weight reduction within the first month, treatment adherence, tolerability profile, frequency of adverse events, and subgroup analyses according to age, sex, baseline BMI, and medication dose.

Statistical analyses will include descriptive statistics, paired parametric or nonparametric comparisons, and exploratory regression analyses to identify predictors of therapeutic response. Statistical significance will be established at p<0.05.

Because this is a retrospective observational study using exclusively secondary data from medical records, the protocol is classified as minimal risk. There will be no direct patient contact, no intervention, and no modification of standard medical care. The study was approved by the Research Ethics Committee of the Hospital Universitário Cassiano Antônio de Moraes / Federal University of Espírito Santo (HUCAM/UFES), Brazil, under approval number 8.403.776 and CAAE 94334125.7.0000.5071.

Study Overview

• Status: Not yet recruiting
• Conditions: Obesity & Overweight
• Intervention / Treatment: Drug: Sibutramine + Topiramate

• Study Type: Observational
• Enrollment (Estimated): 500

Contacts and Locations

• Study Contact: Name: Hugo F Falqueto, MD, MSc; Phone Number: +55 31971271712; Email: hugofalqueto@hotmail.com

Study Locations

• Brazil
  • Espírito Santo
    • Venda Nova do Imigrante, Espírito Santo, Brazil, 29375000
      • Falqueto Med - N1 Centro Clínico

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult patients with obesity or overweight associated with metabolic comorbidities treated in a real-world outpatient clinical setting in Brazil. Participants received combined pharmacological treatment with sibutramine and topiramate during routine medical care. The population includes patients with conditions such as type 2 diabetes mellitus, prediabetes, dyslipidemia, and hypertension who underwent regular clinical follow-up with documented anthropometric and therapeutic data available in medical records for retrospective analysis.

Description

Inclusion Criteria:

• Adults aged 18 years or older at the start of treatment
• Diagnosis of obesity, defined as body mass index (BMI) ≥ 30 kg/m²
• Diagnosis of overweight, defined as BMI ≥ 27 kg/m², associated with at least one metabolic comorbidity, including type 2 diabetes mellitus, prediabetes, dyslipidemia, or arterial hypertension
• Patients treated with concomitant sibutramine and topiramate prescribed during routine outpatient medical care
• Minimum treatment duration of 3 months
• At least two documented outpatient visits, including baseline and follow-up assessments
• Availability of clinical and anthropometric data in the medical record, including body weight, BMI, medication dose, treatment duration, and reported adverse events
• Treatment performed in an outpatient clinical setting under medical supervision

Exclusion Criteria:

• Pregnancy or breastfeeding during the treatment period
• History of epilepsy or seizures
• Severe psychiatric disorders, including schizophrenia, uncontrolled bipolar disorder, or severe depression
• Significant cardiovascular disease, including previous myocardial infarction, stroke, transient ischemic attack, significant coronary artery disease, congestive heart failure, clinically relevant arrhythmias, previous deep vein thrombosis, or pulmonary embolism
• Uncontrolled arterial hypertension, defined as blood pressure ≥ 160/100 mmHg during follow-up
• History of nephrolithiasis
• Closed-angle glaucoma or history of increased intraocular pressure associated with medication use
• Severe renal or hepatic disease
• Concomitant use of medications that may significantly affect body weight, including chronic corticosteroids, atypical antipsychotics, tricyclic antidepressants, other anorectic agents, or other anti-obesity medications
• Incomplete medical records lacking sufficient information on body weight, BMI, medication dose, or minimum clinical follow-up
• Known hypersensitivity to sibutramine, topiramate, or any component of the formulations
• Treatment interruption for more than 1 month associated with weight regain

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Sibutramine + Topiramate Cohort; Retrospective cohort of adult patients with obesity or overweight associated with metabolic comorbidities who received combined treatment with sibutramine and topiramate in a real-world outpatient clinical. Clinical, anthropometric, adherence, and safety data were obtained from medical records for effectiveness and tolerability analysis.

Drug: Sibutramine + Topiramate; Combined pharmacological treatment using sibutramine and topiramate prescribed during routine outpatient clinical practice for the management of obesity and overweight associated with metabolic comorbidities. Medication doses were individualized according to clinical evaluation and tolerability. This retrospective observational study evaluates real-world effectiveness, safety, adherence, and weight reduction outcomes based on medical record review.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent Change in Body Weight	Evaluation of the percentage change in total body weight after treatment with the combination of sibutramine and topiramate in adult patients with obesity or overweight with metabolic comorbidities treated in a real-world outpatient setting.	Baseline to 12 months
Change in Body Mass Index (BMI)	Assessment of the variation in body mass index (BMI) during treatment with sibutramine and topiramate based on retrospective medical record analysis.	Baseline to 12 months

Collaborators and Investigators

• Sponsor: Falquetomed

Publications and helpful links

General Publications

• Astrup A, Caterson I, Zelissen P, Guy-Grand B, Carruba M, Levy B, Sun X, Fitchet M. Topiramate: long-term maintenance of weight loss induced by a low-calorie diet in obese subjects. Obes Res. 2004 Oct;12(10):1658-69. doi: 10.1038/oby.2004.206.
• Cercato C, Stumpf MAM, da Cunha Freire GN, Kawahara EZ, Fernandes AE, de Melo ME, Mancini MC. Combination of sibutramine and topiramate for the treatment of obesity: the SIBAMATE retrospective cohort study : Sibutramine and topiramate for the treatment of obesity. Diabetol Metab Syndr. 2025 Jul 21;17(1):289. doi: 10.1186/s13098-025-01842-1.
• Bray GA, Blackburn GL, Ferguson JM, Greenway FL, Jain AK, Mendel CM, Mendels J, Ryan DH, Schwartz SL, Scheinbaum ML, Seaton TB. Sibutramine produces dose-related weight loss. Obes Res. 1999 Mar;7(2):189-98. doi: 10.1002/j.1550-8528.1999.tb00701.x.

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: May 9, 2026
• First Submitted That Met QC Criteria: May 9, 2026
• First Posted (Actual): May 15, 2026

Study Record Updates

• Last Update Posted (Actual): May 18, 2026
• Last Update Submitted That Met QC Criteria: May 14, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Obesity; Sibutramine; Topiramate; Real-World Evidence; Anti-Obesity Drugs
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity; Carbohydrates; Sugars; Hexoses; Monosaccharides; Fructose; Ketoses; Topiramate; sibutramine
• Other Study ID Numbers: 35972820.1.0000.5564; SIBTOP-2026 (Other Identifier: FALQUETOMED LTDA)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be publicly shared because this is a retrospective real-world study based on confidential medical records containing sensitive clinical information. All data analyzed in the study will be anonymized and presented only in aggregated form to protect participant privacy and comply with ethical and institutional data protection regulations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No