Imipenem/Cilastatin Dosage for UTI Treatment
For complicated urinary tract infections, imipenem/cilastatin should be administered at 500 mg intravenously every 6 hours for 5-7 days. 1, 2
Dosing Recommendations
Standard Dosing for Complicated UTIs
- 500 mg IV every 6 hours for susceptible organisms 2
- Alternative: 1,000 mg IV every 8 hours 2
- For organisms with intermediate susceptibility: 1,000 mg IV every 6 hours 2
- Treatment duration: 5-7 days 1
Administration Method
- 500 mg doses: Administer by IV infusion over 20-30 minutes
- 1,000 mg doses: Administer by IV infusion over 40-60 minutes
- For patients who develop nausea during infusion, the rate may be slowed 2
Renal Dosage Adjustments
Imipenem/cilastatin requires dosage adjustment based on creatinine clearance (CLcr) 2:
| Creatinine Clearance | Dosage for Susceptible Organisms |
|---|---|
| ≥90 mL/min | 500 mg every 6 hours |
| 60-89 mL/min | 400 mg every 6 hours |
| 30-59 mL/min | 300 mg every 6 hours |
| 15-29 mL/min | 200 mg every 6 hours |
| <15 mL/min | Not recommended unless hemodialysis is instituted within 48 hours |
Clinical Considerations
Indications for Imipenem/Cilastatin in UTIs
Imipenem/cilastatin is particularly indicated for complicated UTIs caused by:
- Multidrug-resistant organisms
- Carbapenem-resistant Enterobacterales (CRE) when combined with relebactam 1, 3
Alternative Options for CRE UTIs
- Ceftazidime/avibactam 2.5 g IV q8h
- Meropenem/vaborbactam 4 g IV q8h
- Imipenem/cilastatin/relebactam 1.25 g IV q6h 1
Efficacy and Safety
- Clinical studies have shown high efficacy rates (95-99%) for imipenem/cilastatin in complicated UTIs 4, 5
- Common adverse effects include phlebitis at injection site 6
- Monitor for seizure risk, especially in patients with CNS disorders or renal impairment 2
Important Precautions
- Maximum total daily dosage should not exceed 4 g/day 2
- Not recommended for patients with creatinine clearance <15 mL/min unless hemodialysis is instituted 2
- Increased seizure risk in patients with creatinine clearance <30 mL/min 2
- For patients on hemodialysis, administer after dialysis session 2
- Reconstitute with appropriate diluent (0.9% Sodium Chloride or 5% Dextrose) 2
- Do not use diluents containing benzyl alcohol for neonates 2
Monitoring
- Obtain urine culture and susceptibility testing before initiating therapy 3
- Monitor renal function throughout treatment course
- Assess clinical response within 48-72 hours of initiating therapy
- Consider follow-up urine culture after completion of therapy to confirm eradication
Imipenem/cilastatin remains an effective option for complicated UTIs, particularly when other treatment options are limited due to resistance patterns 7.