A 35-year-old man presents with acute flank pain and is diagnosed with a 6 mm calcium oxalate ureteric stone. He is haemodynamically stable with no fever or signs of infection. What is the drug of choice for medical expulsive therapy?

Explanation

## Medical Expulsive Therapy for Ureteric Stones **Key Point:** Tamsulosin, an alpha-1A adrenergic antagonist, is the drug of choice for medical expulsive therapy (MET) in uncomplicated ureteric stones ≤10 mm. ### Mechanism of Action Tamsulosin relaxes smooth muscle in the ureter and ureteric orifice by blocking α1A receptors, facilitating stone passage. This reduces ureteric peristalsis resistance and increases stone expulsion rates by 20–30%. ### Evidence & Guidelines **High-Yield:** Multiple RCTs and meta-analyses support tamsulosin 0.4 mg once daily for 2–4 weeks as first-line MET. Success rates are highest for stones <10 mm and in the distal ureter. ### Clinical Application | Parameter | Details | |-----------|----------| | **Indications** | Uncomplicated ureteric stones <10 mm, no obstruction, no infection | | **Dosing** | 0.4 mg once daily (evening) | | **Duration** | 2–4 weeks | | **Success rate** | 65–80% for distal stones <10 mm | | **Onset** | Benefits seen within 1–2 weeks | **Clinical Pearl:** MET is cost-effective and reduces need for intervention in appropriately selected patients. Contraindicated in infected obstructed systems (pyonephrosis) and symptomatic complete obstruction with renal dysfunction. ### Supportive Measures - Adequate hydration (2–3 L/day) - NSAIDs for pain control (diclofenac or ibuprofen) - Antiemetics as needed - Regular imaging (ultrasound or plain KUB) to track stone position [cite:Harrison 21e Ch 279]