Hello, I have not noted any interaction between these two medications in the references available to me. However, the antibiotic itself can cause nausea, vomiting, and diarrhea in some people. It is possible that you did not tolerate the antibiotic well. I recommend speaking with your pharmacist, who can contact your doctor if necessary to change the antibiotic. Depending on the situation and the timing of starting Saxenda, your pharmacist may refer you back to your doctor. If you have any other questions, please do not hesitate to reach out.