How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • Go back-and-forth until satisfied
    Rate the answer you receive.
Ask DrOAB Your Own Question
DrOAB, Doctor (MD)
Category: Medical
Satisfied Customers: 1032
Experience:  In practice since 2000.
Type Your Medical Question Here...
DrOAB is online now

Have been on Trimethoprin for three days for a infection

This answer was rated:

Have been on Trimethoprin for three days for a urine infection also taking ibuprofen and paracetamol how long before antibiotics take to work still getting lower back pain

Hello. When taking an antibiotic for a urinary tract infection (UTI), you should see some symptom relief (e.g., fever resolution, decreased urinary and back pain) after three full days of medication treatment. If you have taken the antibiotic for three full days without significant improvement, then I would advise calling your prescribing doctor about a change in antibiotic therapy. If your doctor sent a urine specimen for a bacterial culture test, then such a test may also provide information about which antibiotic therapy would be effective.

Customer: Thank you for your help I don't think the antibiotic is makin any difference and that is the third day I am on now

I realize you are in the UK while I am in the USA, but by comparison, trimethoprim would NOT be a first-line choice in treating a UTI here in the USA.

Customer: Do you suggest another visit to th doctor

You might just call your doctor to request a courtesy change in prescription be called in to the pharmacy.


If a urine culture was performed, ask if it indicates a better antibiotic choice.

DrOAB and other Medical Specialists are ready to help you