Development of a Follow-Up Protocol for Patients Treated with Injectable Semaglutide for Weight Loss: Design of a Research Study in Community Pharmacy.

In 2024, a second brand of injectable semaglutide was marketed, authorized for the indication of weight loss, along with the first tirzepatide. Both are indicated as an adjunct to a low-calorie diet and increased physical activity for weight control, including weight loss and maintenance, in adults with a BMI greater than 27. In Community Pharmacy, we have a Professional Pharmaceutical Service in Nutrition, and it is of interest to study and compare the outcomes obtained by patients using these drugs versus those who only adopt lifestyle changes in diet and physical activity. This is especially relevant after observing that several patients had stopped attending the Nutrition Service, arguing that maintaining diet and increasing physical activity required too much effort, and that they would instead request a prescription for one of these drugs from their primary care physician. A protocol was therefore designed to conduct a research study during 2026 to allow follow-up of patients treated with injectable semaglutide and tirzepatide, since during the dispensing of these medicines it was detected that patients lacked knowledge regarding possible adverse effects and the dietary and physical activity habits they should maintain during treatment. The most frequent adverse effects are gastrointestinal: nausea, vomiting, diarrhea, constipation, abdominal pain; others may also appear such as headache, dizziness, and fatigue, and cases of retinopathy, hypotension, cholelithiasis, and hair loss, among others, have been reported. Data collection will take place during 2026 through various questionnaires and/or interviews with patients who agree to participate in the study. Different questionnaires will be developed to collect important information at each phase of treatment, as well as the outcomes obtained in terms of weight loss and lifestyle habits adopted after initiating pharmacological treatment, in order to perform a statistical analysis of the variables. The main objective of the research will be to assess the results obtained over one year regarding weight loss in patients treated with semaglutide or tirzepatide, as well as adverse effects and, where applicable, rebound effect, and to compare them with the results obtained in other patients from the nutrition service who are not receiving these treatments. With the data obtained, statistical analyses will be carried out to describe the sample, using absolute and relative frequencies for qualitative variables, and means and standard deviations for quantitative ones. Chi-square tests will also be used to compare proportions regarding weight loss, adverse effects, weight maintenance or rebound, and dietary and exercise habits adopted by patients treated with semaglutide or tirzepatide compared with those not using these drugs. In addition, potential DRPs (Drug-Related Problems) and NMOs (Negative Medication Outcomes) will be studied, and health education will be provided, emphasizing the importance of acquiring healthy dietary and physical activity habits.