L-Citrulline Versus Tamsulosin for Medical Expulsive Therapy of Distal Ureteral Stones: A Prospective Randomized Study

This is a prospective, randomized, controlled trial conducted at the outpatient Urology Clinic, Beni-Suef University Hospital.

The study will include adult patients aged 18 to 60 years with a single distal ureteral stone measuring 5 to 10 mm, normal renal function, and controlled pain. Patients with fever or active urinary tract infection, severe hydronephrosis, solitary kidney, pregnancy, previous ureteric surgery, multiple stones, or an indication for urgent surgical intervention will be excluded.

Eligible participants will be randomized in a 1:1 ratio to one of two treatment groups. The L-citrulline group will receive oral L-citrulline 750 mg twice daily. The tamsulosin group will receive oral tamsulosin 0.4 mg once daily. Treatment will be discontinued upon stone passage or after completion of 4 weeks of therapy, whichever occurs first. Both groups will receive standard supportive care, including analgesics as needed, hydration advice, and use of a stone strainer.

Participants will be evaluated weekly for 4 weeks. Follow-up assessments will include symptom review, pain assessment using the Visual Analog Scale, documentation of pain episodes, analgesic requirements, adverse event monitoring, and imaging assessment using ultrasound with or without KUB, with low-dose computed tomography when clinically needed.

The primary outcome is stone expulsion rate within 4 weeks. Stone expulsion will be confirmed by patient-reported stone passage with stone capture, or by absence of the stone on follow-up imaging. Secondary outcomes include time to stone expulsion, number of pain episodes, analgesic use, need for additional intervention such as ureteroscopy or ureteral stenting, and adverse events.