Post-Hydration After Amphotericin B
Administer 0.9% normal saline intravenously (500-1000 mL) 30 minutes before each amphotericin B infusion to reduce nephrotoxicity, and maintain aggressive hydration throughout the treatment course to ensure urine output exceeds 4000 mL/day. 1, 2, 3
Hydration Protocol
Pre-Infusion Hydration
- Administer 1 liter of 0.9% normal saline IV over 30-60 minutes immediately before each amphotericin B dose 1, 2, 4
- This pre-hydration strategy significantly ameliorates nephrotoxicity by maintaining high urine output and facilitating tubular recovery 1, 2
- The sodium load is crucial—studies demonstrate that patients receiving saline supplementation had dramatically lower rates of nephrotoxicity (2/17 patients) compared to those without supplementation (14/21 patients developed renal impairment) 4
During and Post-Infusion Hydration
- Maintain total intravenous hydration of at least 1500 mL/m² body surface area per day, with at least 1 liter being 0.9% saline 5
- Target urine output should exceed 4000 mL/day to prevent tubular damage 3
- Increase hydration by an additional 500-1000 mL if serum creatinine rises by 20% from baseline 5
Electrolyte Monitoring and Replacement
Potassium Management
- Monitor serum potassium at least twice weekly, as hypokalemia occurs in up to 80% of patients 1, 6
- Provide aggressive oral potassium supplementation as needed; severe cases may require IV potassium (7.45% solution via central line) 3
- Replace all urinary potassium losses to maintain normal serum levels 3
Magnesium and Other Electrolytes
- Check magnesium levels twice weekly and supplement losses aggressively 1, 2
- Monitor calcium and bicarbonate for renal tubular acidosis 2, 6
- Supplemental alkali medication may decrease renal tubular acidosis 6
Monitoring Schedule
Renal Function Assessment
- Measure serum creatinine and calculate creatinine clearance every 2-3 days initially, then weekly 2
- Obtain baseline values before starting therapy 6
- Consider 24-hour urine collection for accurate creatinine clearance if using medications that interfere with creatinine secretion 2
Electrolyte Surveillance
- Check serum potassium, magnesium, calcium, and bicarbonate at least twice weekly 2
- Monitor for signs of renal tubular acidosis (check serum bicarbonate and arterial blood gas if acidosis suspected) 2
Formulation-Specific Considerations
Lipid Formulations vs. Deoxycholate
- Lipid formulations (liposomal amphotericin B, amphotericin B lipid complex) have considerably less nephrotoxicity than conventional amphotericin B deoxycholate 7, 1, 2
- If nephrotoxicity develops with deoxycholate, switch to lipid formulations at 4-6 mg/kg daily 2
- Amphotericin B deoxycholate should be reserved for patients at low risk for nephrotoxicity or resource-limited settings 7, 1
Critical Pitfalls to Avoid
Concurrent Nephrotoxins
- Avoid or minimize aminoglycosides, cyclosporine, tacrolimus, and NSAIDs during amphotericin B therapy 2
- Concomitant nephrotoxic medications dramatically worsen outcomes and delay recovery 2
Inadequate Hydration
- The most common error is insufficient hydration—studies show that water restriction in animal models rapidly produces severe renal insufficiency 3
- Patients who had ticarcillin (with obligatory sodium) stopped while on amphotericin B developed nephrotoxicity within one week 4
Long-Term Management
Post-Treatment Monitoring
- Continue monitoring renal function and electrolytes for at least 3-6 months after treatment completion 2, 8
- Permanent tubular dysfunction may require ongoing potassium and magnesium supplementation 2, 8
- Some permanent renal impairment often occurs, especially in patients receiving cumulative doses over 5 grams 6, 8