Antibiotics for an E. coli urinary tract infection

A clinician may start treatment from your symptoms and then adjust it if a urine culture shows that the bacteria resist the first medicine.

E. coli normally lives in the bowel but can enter the urinary tract and cause infection. Burning during urination, needing to pass urine often, and lower abdominal discomfort can occur with a bladder infection. Fever, chills, nausea, or pain in the side or back can indicate that infection has reached a kidney.

The antibiotic choice differs between a bladder infection and a kidney infection because medicines reach these tissues differently. Pregnancy, kidney function, allergies, recent antibiotics, and previous resistant bacteria also influence prescribing.

Take the antibiotic exactly as prescribed and complete the stated course unless the prescriber changes it. Do not use leftover tablets or share medicine: an unsuitable drug can delay effective treatment and cause side effects. Drink enough fluid to avoid dehydration unless you have been told to restrict fluids.

Contact the treating clinic if symptoms are not easing, return soon after treatment, or the laboratory reports resistance. Seek advice before combining the prescription with supplements or other medicines, and report rash, severe diarrhoea, vomiting that prevents dosing, or other troublesome reactions.

Arrange prompt medical assessment for fever with side or back pain, repeated vomiting, visible blood in the urine, worsening weakness, confusion, or very little urine. These features may accompany kidney involvement, dehydration, or a more serious infection.

Urgent assessment is also appropriate if you are pregnant, have significant kidney or immune problems, or are becoming rapidly more unwell. Call emergency services for breathing difficulty, facial or throat swelling, faintness, or a rapidly spreading rash after taking an antibiotic.

Ask whether a urine culture is needed, when results should be available, and how you will be contacted if treatment must change. Clarify which side effects warrant stopping the medicine, whether it interacts with your regular medicines, and what follow-up is appropriate if infections recur.