Hello and welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. It is possible for Nitrofurantoin to cause nausea and stomach discomfort. In general it is present with just the first doses and it gets better. So if it is not very much, and you can handle it, I would say to continue the antibiotic. Try to take it with food. You can also buy an antiacid over the counter to take during the time that you are using Nitrofurantoin. If what I am suggesting above is not enough and you think the nausea is bothering you too much, then consider going to your doctor so they can suggest another antibiotic. Keep in mind though that it is very important for the UTI to be treated well, otherwise it may get worse and cause a kidney infection. So do not stop it without making sure that your doctor will give you another antibiotic in the following hours. Hope I have answered your query. Let me know if I can assist you further. Kind regards, Dr. Papaqako