In an adult with acute renal colic due to a ureteral stone and normal renal function, what oral NSAID regimen is recommended as first‑line analgesia, including dosing, duration, and contraindications?

Oral NSAIDs for Acute Renal Colic: First-Line Analgesic Regimen

NSAIDs are the first-line analgesic for acute renal colic in adults with normal renal function, with diclofenac and ibuprofen being the most strongly recommended agents. 1, 2, 3

Recommended NSAID Regimens

First-Line Options

• Diclofenac: Has the strongest evidence base for renal colic and is specifically recommended by multiple guidelines 2, 3
• Ibuprofen: 400-600 mg orally every 6-8 hours (maximum 3200 mg/day in divided doses) 2
• Metamizole: Where available, can be used as an alternative 2

Duration of Treatment

• Maximum 5 days for acute renal colic to minimize nephrotoxicity risk 2, 4
• Use the shortest effective duration necessary 2

Mechanism and Superiority Over Opioids

NSAIDs are superior to opioids for kidney stone pain because they reduce intraureteral pressure by decreasing inflammation and ureteric spasm, directly addressing the pathophysiology of renal colic. 1, 3, 5

• NSAIDs reduce the need for additional analgesia compared to opioids 6
• NSAIDs cause less vomiting than opioid therapy 6
• Patients receiving NSAIDs are significantly less likely to require rescue medication than those receiving placebo (RR 0.35,95% CI 0.20 to 0.60) 6

Mandatory Pre-Treatment Assessment

Before prescribing any NSAID for renal colic, you must evaluate renal function (BUN, creatinine, GFR), as this is the critical determinant of safety. 2

Required Laboratory/Clinical Evaluation:

• Renal function: Calculate eGFR; NSAIDs are relatively contraindicated if baseline renal impairment exists 1, 2
• Age: Patients ≥60 years have increased risk of NSAID complications 2, 4
• Hydration status: Dehydration significantly increases nephrotoxicity 2
• Cardiovascular history: NSAIDs increase CV risk, particularly in patients with existing disease 1, 2
• GI history: Screen for peptic ulcer disease or GI bleeding history 1, 2, 7
• Current medications: Check for anticoagulants, antiplatelet agents, or other nephrotoxic drugs 2, 4

Absolute Contraindications to NSAIDs

Do not prescribe NSAIDs if any of the following are present: 1, 2, 4

• Severe renal impairment (GFR <30 mL/min or creatinine doubled from baseline) 1, 2
• Dehydration or volume depletion 2, 4
• Active GI bleeding or peptic ulcer disease 2, 4, 7
• Concurrent nephrotoxic medications 2
• Severe cardiovascular disease 2
• Concurrent anticoagulation that cannot be interrupted 4

Monitoring During NSAID Therapy

While using NSAIDs for renal colic, monitor for the following and discontinue immediately if they occur: 2, 4

• BUN or creatinine doubles from baseline 2, 4
• New or worsening hypertension 2, 4
• Any signs of GI bleeding 4
• Ensure adequate hydration (critical for both stone passage and NSAID safety) 2

Alternative Analgesic Strategy When NSAIDs Are Contraindicated

If NSAIDs cannot be used due to renal impairment or other contraindications, opioids become second-line therapy. 2

Second-Line Options:

• Opioids: Hydromorphone, tramadol, or pentazocine (avoid meperidine/pethidine) 2
• Acetaminophen/Paracetamol: Can be used but is significantly less effective than NSAIDs for renal colic 2
• Oral corticosteroids: 30-35 mg/day prednisolone equivalent for 3-5 days (though this is primarily recommended for gout, not renal colic) 1

Dosing Adjustments for Elderly:

• Downward-adjusted opioid doses are necessary in elderly patients to prevent confusion and respiratory depression 7
• Monitor closely for adverse effects 7

Common Pitfalls to Avoid

• Do not combine multiple NSAIDs (e.g., ketorolac with ibuprofen), as toxicities are additive without additional analgesic benefit 4
• Do not use NSAIDs for prolonged periods beyond 5 days for acute renal colic 2, 4
• Do not assume normal renal function without laboratory confirmation, especially in elderly patients or those with comorbidities 2, 7
• Do not prescribe NSAIDs in dehydrated patients without first ensuring adequate hydration 2

Risk-Benefit Consideration

For acute, short-term use (days, not weeks), the risk-benefit ratio favors NSAIDs as first-line therapy because they directly reduce intraureteral pressure and inflammation, despite potential nephrotoxicity concerns. 2, 5

• The short duration of treatment (≤5 days) minimizes cumulative renal toxicity 2
• NSAIDs are far more effective than alternatives for the specific pathophysiology of renal colic 5, 6
• Major adverse effects are rarely reported in the literature for short-term NSAID use in renal colic 6