Hello, Thank you for asking at HCM. I carefully read your question and understand your concern. If you are taking an oral medication it is always a risk it might cause some nausea and vomiting even though it might not be the most common side effect of it and every patient is unique in the way he responds to treatments. There are other antibiotics that can be tried for infection. So I would recommend you to see your doctor again (have another visit with him) and speak with him if he can change your antibiotic for a few reasons: 1. you have been on this antibiotic for at least 3 days and you are still having chills, normally fever should be down in 2 days if antibiotic is effective 2. it is always advisable to try a different oral treatment if the patient is throwing up with one medication. 3. if you are getting worse and having new symptoms like throwing up you need to see your doctor for another evaluation anyway, to make sure the diagnosis accurate and if there is a need for a different treatment plan.. Something else the doctor can do is give you something against vomiting (antiemetic). If this does not help than changing the antibiotic is the only option. Meanwhile make sure you drink frequent small amounts of fluids and keep yourself hydrated. Hope this is helpful and answers to your question