A 35-year-old man presents with acute colicky flank pain and hematuria. Non-contrast CT confirms a 6 mm calcium oxalate stone in the right mid-ureter. He is hemodynamically stable with no fever or signs of obstruction. What is the drug of choice for acute pain management and stone passage?

Explanation

## Drug of Choice for Acute Ureteric Colic **Key Point:** NSAIDs are the first-line analgesics for acute renal/ureteric colic in uncomplicated cases. Among NSAIDs, **indomethacin** is classically cited as the drug of choice in most Indian surgical and urology textbooks (Bailey & Love, Smith's Urology), though diclofenac and ibuprofen are equally acceptable per contemporary EAU/AUA guidelines. ### Mechanism of Action NSAIDs inhibit prostaglandin synthesis (COX-1 and COX-2), reducing: - Ureteric smooth muscle tone and peristaltic amplitude - Renal blood flow and glomerular filtration rate (↓ urine production → ↓ intraluminal pressure proximal to stone) - Local inflammatory mediator release This dual analgesic and pressure-reducing action makes NSAIDs superior to opioids for ureteric colic. ### Comparative Overview | Feature | Indomethacin | Ibuprofen | Paracetamol | Morphine | |---------|---|---|---|---| | **Analgesic efficacy** | Excellent | Good–Excellent | Moderate | Excellent | | **Ureteric relaxation** | Yes (via PG inhibition) | Yes | No | No | | **Stone passage rate** | Increases | Increases | No effect | No effect | | **First-line status** | Yes (classical DOC) | Yes (equally acceptable) | No | Opioid reserve | | **Route** | IV/IM/PR (rapid onset) | Oral/IV | Oral | IV/IM | **High-Yield:** Indomethacin 50 mg IM/IV or 100 mg PR is the standard acute dose with onset within 15–30 minutes. Diclofenac 75 mg IM is also widely used. ### Why Not Morphine? Opioids reduce ureteric peristalsis (they do not cause frank spasm, but diminish the coordinated propulsive contractions that help move the stone distally). They do not lower intraluminal pressure proximal to the stone and are associated with higher rates of nausea/vomiting. Morphine is reserved for severe pain unresponsive to NSAIDs or when NSAIDs are contraindicated (renal insufficiency, bleeding diathesis, allergy, or fever with obstruction suggesting urosepsis). ### Why Indomethacin Over Ibuprofen in This Context? Both indomethacin and ibuprofen are NSAIDs with equivalent analgesic efficacy for ureteric colic. Indomethacin is traditionally preferred in Indian surgical textbooks (Bailey & Love, Smith & Tanagho) due to its rapid parenteral/rectal availability and potent COX inhibition. Contemporary EAU/AUA guidelines list diclofenac and ibuprofen as equally acceptable first-line agents. In an examination context asking for the **classical drug of choice**, indomethacin remains the standard answer per Indian postgraduate curricula. ### Clinical Pearl NSAIDs increase stone passage rates by approximately 30–40% in uncomplicated cases for stones < 10 mm, making them preferable to opioids as first-line therapy. Alpha-blockers (tamsulosin) may be added as medical expulsive therapy for stones 5–10 mm. **Contraindications to NSAIDs:** - eGFR < 30 mL/min - Active peptic ulcer / bleeding diathesis - NSAID allergy - Fever + obstruction (risk of urosepsis — use opioids instead) *(References: Bailey & Love's Short Practice of Surgery, 27th ed.; EAU Guidelines on Urolithiasis 2023; Smith & Tanagho's General Urology, 19th ed.)*