Can pantoprazole (Proton Pump Inhibitor) cause interstitial nephritis?

Can Pantoprazole Cause Interstitial Nephritis?

Yes, pantoprazole can definitely cause acute interstitial nephritis (AIN), which is listed as a serious side effect in its FDA drug label and has been documented in multiple case reports.

Evidence from FDA Drug Label

The FDA medication guide for pantoprazole explicitly warns about this risk:

• Pantoprazole can cause "a type of kidney problem (acute interstitial nephritis)" that "can happen at any time during treatment" 1
• The label advises patients to "call your doctor right away if you have a decrease in the amount that you urinate or if you have blood in your urine" 1
• Hypersensitivity reactions to pantoprazole may include "acute tubulointerstitial nephritis" among other serious reactions 1

Clinical Presentation of Pantoprazole-Induced Interstitial Nephritis

Pantoprazole-induced AIN typically presents with:

• Elevated serum creatinine (acute kidney injury)
• Oliguria (decreased urine output)
• Systemic symptoms may include:
  • Fever
  • Fatigue/malaise
  • Arthralgia (joint pain)
  • Flank pain 2

Timing and Diagnosis

• AIN typically develops after several weeks of pantoprazole exposure (reported cases show development after 4-8 weeks of therapy) 2, 3, 4
• Diagnostic findings include:
  • Eosinophils in urine
  • Renal biopsy showing interstitial mononuclear cells, plasma cells, and eosinophilic infiltrates 2, 4

Mechanism and Risk Factors

Pantoprazole-induced AIN is a drug hypersensitivity reaction rather than a direct toxic effect:

• It is not dose-dependent
• It can occur at any time during treatment
• It represents an immune-mediated reaction to the drug 2

Management

If pantoprazole-induced AIN is suspected:

1. Immediately discontinue pantoprazole
2. Consider corticosteroid therapy (typically prednisone 1 mg/kg/day)
3. Monitor renal function for improvement 2, 3, 5

Early detection and management are crucial as continued exposure can lead to progressive renal damage. One case report demonstrated that even with ongoing drug exposure, steroids led to resolution of inflammatory infiltrates, though drug discontinuation remains the primary intervention 5.

Prognosis

With prompt recognition and management:

• Complete recovery of renal function occurs in approximately 50% of cases
• Partial recovery occurs in the remaining cases 4
• Delayed diagnosis and treatment may lead to permanent renal impairment

Rare Complications

Beyond acute interstitial nephritis, there is a case report of pantoprazole causing chronic tubulointerstitial nephritis with concurrent peripheral neuropathy, mimicking systemic disease 6. This suggests that the nephrotoxic effects of pantoprazole may occasionally present with additional neurological manifestations.

Monitoring Recommendations

For patients on pantoprazole therapy:

• Monitor renal function at baseline and periodically during treatment
• Maintain vigilance for symptoms of AIN, especially during the first few months of therapy
• Consider more frequent monitoring in patients with pre-existing kidney disease or other risk factors