Steroid Duration for Interstitial Nephritis
For acute interstitial nephritis, initiate prednisone at 0.5-1 mg/kg/day (typically 60 mg daily) and taper over 8 weeks total, with high-dose treatment maintained for 2-3 weeks before beginning the taper. 1, 2
Initial Dosing and High-Dose Phase
- Start with prednisone 0.5-1 mg/kg/day (typically 60 mg daily as a single morning dose) 1, 2, 3
- Maintain this high dose for 2-3 weeks before initiating taper 2
- In immune checkpoint inhibitor-related AIN, consider higher initial doses such as methylprednisolone 500-1000 mg IV daily for 3 days, followed by oral prednisone 4
Tapering Schedule
- Total treatment duration should be approximately 8 weeks from initiation to completion 1
- After the initial 2-3 week high-dose phase, begin tapering the dose gradually over the remaining 5-6 weeks 1, 3
- One effective rapid taper protocol: reduce from 60 mg daily to 10 mg within 3 weeks, which has shown equivalent outcomes to longer tapers 5
- Standard taper: reduce to 10 mg over 6 weeks 5
Critical Timing Considerations
The most important factor is early initiation—delayed steroid treatment is associated with worse kidney recovery. 2
- Each day of delay in starting steroids increases the odds of incomplete renal recovery 2
- Prolonging high-dose treatment beyond 3 weeks does NOT improve outcomes 2
- Extending total treatment duration beyond 8 weeks does NOT provide additional benefit 2
Common Pitfalls to Avoid
- Do not delay steroid initiation while waiting for biopsy confirmation if clinical suspicion is high—delayed treatment (even by days) worsens outcomes 2
- Do not continue high-dose steroids beyond 3 weeks thinking it will improve recovery—it won't, and only increases toxicity risk 2
- Discontinue all nephrotoxic medications (especially proton pump inhibitors and trimethoprim-sulfamethoxazole) during treatment, as continued exposure significantly delays recovery 5
- Do not extend treatment beyond 8 weeks unless there are specific indications—longer courses do not improve kidney function recovery 2
Monitoring Response
- Assess treatment response by monitoring serum creatinine and eGFR 1, 3
- Complete remission is defined as eGFR improvement to ≥60 mL/min/1.73 m² 3
- Partial remission is improvement but eGFR remains <60 mL/min/1.73 m² 3
- Most patients who will respond show improvement within the first 2-4 weeks of treatment 2
Route of Administration
Oral prednisone is equally effective as IV pulse methylprednisolone for drug-induced AIN. 3
- Oral prednisone 1 mg/kg daily for 2 weeks followed by taper achieves similar outcomes to IV methylprednisolone 30 mg/kg for 3 days (max 1 g) followed by oral prednisone 3
- Choose IV route only if oral administration is not feasible or in severe immune checkpoint inhibitor-related cases 4, 3
Prognostic Factors
Poor recovery is associated with: