after signing the consent form, you are randomly assigned to one of two treatment options. the first option is the experimental drug fosfomycin (also called fosfomycin‑trometamol). the second option is a standard antibiotic, which may be a fluoroquinolone such as ofloxacin, levofloxacin or ciprofloxacin, or the combination drug sulfamethoxazole‑trimethoprim (also known as cotrimoxazole). the assignment is made by the study computer and you will not know which group you are in.

the purpose of randomization is to compare the effectiveness of the experimental drug with the standard antibiotics in men who have a fever and a urinary tract infection caused by susceptible bacteria.

you will be given the medication that corresponds to your assigned group. the dosage is written on the medication label and explained by the study staff.

if you are assigned to the experimental group, you will take fosfomycin 3 g (three grams) by mouth once each day for a total of 12 days.

if you are assigned to the standard‑treatment group, you will take the prescribed fluoroquinolone (for example, ofloxacin 400 mg, levofloxacin 500 mg, or ciprofloxacin 1000 mg) or the combination sulfamethoxazole‑trimethoprim at the dose indicated by the study protocol, taken by mouth each day for 12 days. the exact number of tablets and timing (morning and evening) will be explained to you.

each day you should measure your body temperature. a temperature below 38 °C (100.4 °F) is considered normal.

you should also note any urinary symptoms such as pain, urgency, or burning while urinating, and report if they improve or worsen.

do not take any other antibiotics or medicines for the infection unless you are told to do so by the study team.

if you experience side effects such as nausea, rash, diarrhea, or any new symptoms, write them down and inform the study staff at the next visit or by the contact method provided in your study diary.

after the twelfth dose, you stop taking the study medication. keep the medication package for the study record, but do not use any leftover tablets.

14 days after you finish the medication (which is day 26 of the study), you return to the clinic for the primary evaluation.

the study staff will check your temperature, ask about any remaining urinary symptoms, and verify that you have not needed any additional antibiotics.

a urine sample may be collected to confirm that the infection has cleared.

a rectal swab may be taken to test for the presence of antibiotic‑resistant bacteria. this helps the researchers understand if resistant bacteria are carried after treatment.

28 days after the end of treatment (day 40 of the study), you attend a second follow‑up visit.

the staff will ask whether you have had any new episodes of fever or urinary tract infection, which are recorded as a possible recurrence.

any additional health information since the previous visit is also collected.

after the day‑40 visit, no further study visits are required. the data you provided will be used by the researchers to compare the two treatment groups.

you may be asked to keep a short record of any late side effects for a few weeks, but no additional clinic visits are scheduled.