What is the next step in managing a 66-year-old male with impaired renal function (elevated creatinine, eGFR of 35) and normal BUN, currently using NSAIDs?

Management of NSAID-Induced Renal Impairment in a 66-Year-Old Male

The immediate next step for a 66-year-old male with elevated creatinine, eGFR of 35, and normal BUN who is currently using NSAIDs is to discontinue the NSAID immediately to prevent further renal damage. 1

Assessment of Current Situation

The patient presents with:

• Elevated creatinine
• eGFR of 35 ml/min/1.73m² (indicating Stage 3B chronic kidney disease)
• Normal BUN
• Current NSAID use
• Age 66 (increased risk factor)

Management Algorithm

1. Immediate Discontinuation of NSAIDs

   • NSAIDs should be avoided in patients with preexisting renal disease to prevent acute renal failure 1
   • All NSAIDs (selective and non-selective) can cause volume-dependent renal failure, interstitial nephritis, and nephrotic syndrome 1

2. Rehydration Assessment

   • Evaluate for signs of volume depletion
   • Consider IV fluids if clinically dehydrated
   • Normal BUN suggests patient may not be significantly volume depleted

3. Alternative Pain Management

   • Switch to acetaminophen (up to 3g/day) for pain control 1
   • Consider opioid analgesics if necessary as they are safer alternatives to NSAIDs for patients with renal impairment 1

4. Laboratory Monitoring

   • Recheck renal function (creatinine, BUN, eGFR) within 1 week after NSAID discontinuation
   • Monitor electrolytes, particularly potassium levels
   • Urinalysis to check for proteinuria or hematuria

5. Medication Review

   • Evaluate for other nephrotoxic medications
   • Assess for "triple whammy" combination (NSAIDs + diuretics + ACE inhibitors/ARBs) which significantly increases renal risk 1
   • Consider temporary dose reduction of ACE inhibitors or ARBs if patient is taking them 1

Expected Outcome

After NSAID discontinuation, significant improvement in renal function can be expected. Research shows that patients with Stage 3 CKD who discontinued NSAIDs experienced an increase in eGFR from 45.9 to 46.9 ml/min/1.73m² 2.

Common Pitfalls to Avoid

1. Continuing NSAIDs at a lower dose - Even reduced doses can cause renal damage in susceptible individuals

2. Switching to a different NSAID - All NSAIDs, including COX-2 inhibitors, carry renal risks in patients with impaired kidney function 1

3. Failing to monitor for improvement - Renal function should be rechecked within 1 week to confirm improvement

4. Overlooking other nephrotoxic medications - Review all medications for potential nephrotoxicity

5. Inadequate patient education - Patient must understand the importance of avoiding all NSAIDs, including over-the-counter preparations 1

Long-term Considerations

If renal function does not improve after NSAID discontinuation, consider:

• Nephrology consultation
• Evaluation for other causes of renal dysfunction
• Possible renal biopsy if suspicion for NSAID-induced interstitial nephritis

The revised Beers criteria indicate moderate evidence to support complete NSAID avoidance in elderly patients with creatinine clearance <30 ml/min 1. With an eGFR of 35, this patient is approaching this threshold and should permanently avoid NSAIDs to prevent progression to more advanced kidney disease.