What happens when administering Intravenous (IV) antibiotics on the same day as dialysis?

Administering IV Antibiotics on the Same Day as Dialysis

IV antibiotics should be administered after the dialysis session to prevent premature removal of the drugs and ensure optimal therapeutic concentrations. 1

Timing Considerations

• Post-dialysis administration: Antibiotics should be given after hemodialysis on dialysis days to avoid:

  • Premature removal of antibiotics during dialysis
  • Underdosing of medications
  • Need for supplemental dosing 1

• Exception: Antibiotics that are not significantly removed by dialysis (e.g., rifampin, ethionamide) can be given before dialysis 1

Antibiotic-Specific Considerations

Antibiotics Not Requiring Dose Adjustment

These can be given at standard doses after dialysis:

• Isoniazid: 300 mg once daily or 900 mg three times per week 1
• Rifampin: 600 mg once daily or 600 mg three times per week 1
• Ethionamide: 250-500 mg daily 1

Antibiotics Requiring Dose Adjustment

These require modified dosing schedules:

• Vancomycin:

  • 20 mg/kg loading dose during the last hour of dialysis session
  • 500 mg during the last 30 minutes of each subsequent dialysis session 1, 2
  • Target pre-dialysis levels: 10-20 μg/mL for most infections 3

• Aminoglycosides (e.g., gentamicin):

  • 1 mg/kg (not exceeding 100 mg) after each dialysis session 1, 4
  • Avoid if possible due to risk of ototoxicity 1

• Cephalosporins:

  • Cefazolin: 20 mg/kg IV after each dialysis session 1
  • Ceftazidime: 1 g IV after each dialysis session 1
  • Pyrazinamide: 25-35 mg/kg three times weekly (not daily) 1
  • Ethambutol: 15-25 mg/kg three times weekly (not daily) 1

Antibiotic Lock Therapy for Catheter-Related Infections

When treating catheter-related bloodstream infections in dialysis patients:

• Systemic antibiotics should be combined with antibiotic lock therapy for catheter salvage 1
• The antibiotic lock solution should be renewed after each dialysis session 1
• Recommended antibiotic lock concentrations:
  • Vancomycin: 2.5-5.0 mg/mL with 2500-5000 IU/mL heparin
  • Cefazolin: 5.0 mg/mL with 2500-5000 IU/mL heparin
  • Gentamicin: 1.0 mg/mL with 2500 IU/mL heparin 1

Monitoring Recommendations

• Serum drug concentrations: Monitor levels for antibiotics with narrow therapeutic ranges (e.g., vancomycin, aminoglycosides) 1
• Vancomycin: Measure trough levels after the third dose, aiming for pre-dialysis levels of 10-20 μg/mL 3
• Clinical response: Daily evaluation of treatment response 3
• Surveillance cultures: Obtain one week after completing antibiotic treatment if catheter is retained 1

Common Pitfalls to Avoid

1. Premature administration: Giving antibiotics before dialysis can lead to significant drug removal and therapeutic failure 1

2. Inappropriate dosing: Failure to adjust doses based on residual renal function can lead to toxicity 1, 4

3. Overlooking drug interactions: Some antibiotics may interact with other medications commonly used in dialysis patients 1

4. Inadequate monitoring: Failure to monitor drug levels can lead to subtherapeutic concentrations or toxicity 1

5. Using nephrotoxic antibiotics: Aminoglycosides should be avoided when possible due to risk of ototoxicity; cephalosporins are preferred for gram-negative coverage 1

By following these guidelines, clinicians can optimize antibiotic therapy in dialysis patients, ensuring adequate antimicrobial coverage while minimizing the risk of toxicity and treatment failure.