I know the rarely prescribed antibiotics such as rifampin can cause any type of birth control to become less effective. But what about everyday, UTI antibiotics? I had a UTI recently and was prescribed Bactrim. I was unable to find out if Bactrim would affect my Nexplanon, and the doctors office wouldn’t return my calls for me to ask. Since Nexplanon isn’t ingested, is it safe to use with common antibiotics without backup?