Patient description: The patients is a 25-year-old G1 P1 pregnant woman who is 24W3D gestational old who developed a sudden unset of fever and chills, accompany with nausea and vomiting. She also complains of dysuria, urgency and frequency. She also reports some severe pain in the flank. Her vital signs are: T = 39.7ºC, P = 117, R = 20, and BP = 113/74 mm Hg. Physical examination reveals tenderness on palpation of both costovertebral angles. She has no history of recurrent UTI prior to her pregnancy or any other underlying disease. The urine culture showed Gram-negative rod-shaped bacterial cells, leukocytes, and leukocyte casts. The blood culture is negative. A CBC shows Hb 12.9 g/dL, Hct 39%, MCV 76 fL, WBC count 14,120/µL.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Uncomplicated Urinary Tract Infections Female patients ≥18 years of age with 24-96 hours of urinary symptoms attributable to a urinary tract infection (UTI) 2. Two of the following signs and symptoms of uUTI: urinary frequency, urinary urgency, pain or burning micturition, suprapubic pain 3. A mid-stream urine specimen with: 1. a dipstick analysis positive for nitrite AND 2. evidence of pyuria as defined by either: i. a dipstick analysis positive for leukocyte esterase ii. at least 10 white blood cells per cubic millimeter on microscopic analysis of unspun urine iii. White blood cell count ≥10 cells/high-powered field in the sediment of a spun urine 4. Has given written informed consent to participate in the study  Presence of signs and symptoms suggestive of acute pyelonephritis: fever (temperature > 38°Celsius), chills, costovertebral angle tenderness, flank pain, nausea, and/or vomiting 2. Receipt of antibacterial drug therapy potentially effective as treatment of uUTI within the prior 7 days 3. Concurrent use of non-study treatments that would have a potential effect on outcome evaluations in patients with uUTI 4. Patients with ileal loops or urinary stoma 5. Patients with an indwelling urinary catheter in the previous 30 days 6. Patients with paraplegia 7. Patients who are likely to receive ongoing antibacterial drug prophylaxis after treatment of uUTI (e.g., patients with vesico-ureteral reflux) 8. Any history of trauma to the pelvis or urinary tract 9. Patient's urine culture, if available at study entry, identify more than 2 microorganisms regardless of colony count or patient has a confirmed fungal UTI 10. Patient is receiving hemodialysis or peritoneal dialysis or had a renal transplant 11. Known history of creatinine clearance <50 mL/min 12. Patients known to have liver disease 13. Patients who are pregnant, or females of child-bearing age unable to take adequate contraceptive precautions 14. Patients with uncontrolled diabetes mellitus 15. Patients with history of blood dyscrasias 16. Patients with history of uric acid kidney stones 17. Patients with acute gouty attack 18. Patients on chronic methotrexate therapy 19. Patient known to be immunocompromised 20. Patients with a known history of myasthenia gravis 21. Patients who require concomitant administration of tizanidine or valproic acid 22. Patients with a history of allergy or hypersensitivity to carbapenems, beta-lactams, quinolones or probenecid 23. Patient is considered unlikely to survive the 4-week study period or has a rapidly progressive or terminal illness including septic shock which is associated with a high risk of mortality 24. History of seizures 25. Use of any other investigational drug in the 30 days prior to the study