A 58-year-old man with a 10-year history of osteoarthritis of the knee presents with severe joint pain. He has been taking ibuprofen 400 mg three times daily for the past 6 months with good symptomatic relief. On examination, he has a blood pressure of 148/92 mmHg (previously 130/80 mmHg 6 months ago). His serum creatinine has risen from 0.9 mg/dL to 1.4 mg/dL, and urinalysis shows mild proteinuria. He denies any other systemic symptoms. What is the most appropriate next step in management?

Explanation

## Clinical Assessment This patient demonstrates **NSAID-induced renal injury and hypertension**, both reversible but serious adverse effects that mandate discontinuation. ### Evidence of NSAID Toxicity | Finding | Significance | |---------|-------------| | Serum creatinine rise (0.9 → 1.4 mg/dL) | ~55% increase; indicates functional renal impairment | | Proteinuria on urinalysis | Glomerular involvement; sign of NSAID-induced nephropathy | | New-onset hypertension (130/80 → 148/92) | NSAID-induced via sodium retention and prostaglandin inhibition | | Timeline: 6 months of NSAID use | Sufficient duration for cumulative renal and vascular toxicity | **Key Point:** NSAIDs inhibit renal prostaglandin synthesis, reducing glomerular filtration rate and causing sodium/fluid retention. This is particularly dangerous in older patients and those with baseline renal disease or hypertension. ### Management Algorithm ```mermaid flowchart TD A[NSAID use + rising creatinine + proteinuria]:::outcome --> B{Reversible injury?}:::decision B -->|Yes - early stage| C[Discontinue NSAID immediately]:::action C --> D[Recheck renal function in 2 weeks]:::action D --> E{Creatinine normalizes?}:::decision E -->|Yes| F[Switch to safer analgesic]:::action E -->|No| G[Nephrology referral]:::urgent F --> H[Acetaminophen or topical NSAID]:::action B -->|No - advanced| I[Nephrology referral]:::urgent ``` **High-Yield:** NSAID-induced renal injury is often **reversible if caught early** (within 6 months). Discontinuation typically restores renal function within 2–4 weeks in uncomplicated cases. **Clinical Pearl:** The combination of rising creatinine + proteinuria + new hypertension in an NSAID user is pathognomonic for NSAID nephropathy. Do not mask the problem with antihypertensives; remove the offending agent. ### Alternative Analgesics After NSAID Discontinuation - **Acetaminophen:** Safe in renal disease (max 3 g/day); no renal or cardiovascular toxicity - **Topical NSAIDs:** Minimal systemic absorption; safe in renal impairment - **Tramadol or weak opioids:** If acetaminophen insufficient (short-term only) - **Physical therapy, weight loss, intra-articular steroid injections:** Non-pharmacological options **Warning:** Do NOT switch to a COX-2 inhibitor (celecoxib) in this patient—it carries the same renal and cardiovascular risks as non-selective NSAIDs, especially in the setting of existing renal dysfunction. [cite:KD Tripathi 8e Ch 12]