L-Citrulline Versus Tamsulosin for Medical Expulsive Therapy of Distal Ureteral Stones

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

This study will compare L-citrulline and tamsulosin as medical expulsive therapy for adults with single distal ureteral stones.

Eligible participants with a single distal ureteral stone measuring 5 to 10 mm will be randomly assigned to receive either oral L-citrulline 750 mg twice daily or oral tamsulosin 0.4 mg once daily. Treatment will continue until documented stone passage or completion of 4 weeks of therapy, whichever occurs first.

Participants will be followed weekly for up to 4 weeks. The main outcome is stone expulsion within 4 weeks. The study will also assess time to stone expulsion, pain episodes, analgesic use, need for additional intervention, and adverse events.

Study Overview

• Status: Recruiting
• Conditions: Urolithiasis; Ureteral Calculi; Distal Ureteral Stone
• Intervention / Treatment: Drug: L-Citrulline; Drug: Tamsulosin

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Hany F Badawy, MD; Phone Number: +201149525028; Email: HANYFATHY86@GMAIL.COM
• Study Contact Backup: Name: Ahmed Gmal, Md; Phone Number: +20 11 18206022; Email: Drhanyfathy86@GMAIL.COM

Study Locations

• Egypt
  • Beni Suweif Governorate
    • Banī Suwayf, Beni Suweif Governorate, Egypt, 02456
      • Recruiting
      • Department of Urology- Beni-Suef University Hospitals
      • Contact: Hany F Badawy, MD; Phone Number: +201149525028; Email: HANYFATHY86@GMAIL.COM
      • Principal Investigator: Hany F Badawy, MD
      • Contact: Mahmoud Abdallah, Md; Phone Number: +20 11 55361979; Email: Mahmoud.abdalla@med.bsu.edu.eg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 to 60 years.
• Single distal ureteral stone.
• Stone size 5 to 10 mm.
• Normal renal function.
• Controlled pain.
• Willingness to comply with follow-up for 4 weeks.
• Written informed consent.

Exclusion Criteria:

• Fever or active urinary tract infection.
• Severe hydronephrosis.
• Solitary kidney.
• Pregnancy.
• Previous ureteric surgery.
• Multiple ureteral stones.
• Indication for urgent surgical intervention.
• Known hypersensitivity or contraindication to L-citrulline or tamsulosin.
• Inability to complete follow-up.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: L-Citrulline Plus Tamsulosin Placebo; Participants will receive oral L-citrulline 750 mg twice daily plus a matched tamsulosin placebo once daily. Treatment will continue until documented stone passage or completion of 4 weeks of therapy, whichever occurs first. Standard supportive care will be provided as needed.	Drug: L-Citrulline; Oral L-citrulline 750 mg twice daily will be administered until documented stone passage or completion of 4 weeks of therapy, whichever occurs first.
Active Comparator: Tamsulosin Plus L-Citrulline Placebo; Participants will receive oral tamsulosin 0.4 mg once daily plus a matched L-citrulline placebo twice daily. Treatment will continue until documented stone passage or completion of 4 weeks of therapy, whichever occurs first. Standard supportive care will be provided as needed.	Drug: Tamsulosin; Oral tamsulosin 0.4 mg once daily will be administered until documented stone passage or completion of 4 weeks of therapy, whichever occurs first.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stone Expulsion Rate Within 4 Weeks	Stone expulsion rate will be defined as the proportion of randomized participants with confirmed stone passage within 4 weeks. Stone expulsion will be confirmed by patient-reported stone passage with stone capture, or by absence of the ureteral stone on follow-up imaging.	Within 4 weeks after randomization

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Stone Expulsion	Time to stone expulsion will be defined as the number of days from randomization to confirmed stone passage. Stone passage will be confirmed by patient-reported stone passage with stone capture, or by absence of the ureteral stone on follow-up imaging.	From randomization up to 4 weeks
Number of Pain Episodes	The number of renal colic pain episodes reported by each participant during the follow-up period will be recorded and compared between the study groups.	From randomization up to 4 weeks
Analgesic Use	Analgesic use will be assessed by recording the number of analgesic doses required by each participant during the follow-up period.	From randomization up to 4 weeks

Collaborators and Investigators

• Sponsor: Beni-Suef University
• Investigators: Principal Investigator: Hany F Badawy, MD, Faculty of Medicine, Beni-Suef University

Study record dates

Study Major Dates

• Study Start (Actual): May 6, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: May 25, 2026
• First Submitted That Met QC Criteria: May 25, 2026
• First Posted (Actual): June 1, 2026

Study Record Updates

• Last Update Posted (Actual): June 1, 2026
• Last Update Submitted That Met QC Criteria: May 25, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Tamsulosin; L-Citrulline; Medical Expulsive Therapy; Ureteral Stone Passage
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urinary Calculi; Ureteral Diseases; Pathological Conditions, Signs and Symptoms; Ureterolithiasis; Ureteral Calculi; Urolithiasis; Amino Acids, Peptides, and Proteins; Sulfur Compounds; Organic Chemicals; Hydrocarbons; Hydrocarbons, Cyclic; Hydrocarbons, Aromatic; Amides; Amino Acids; Benzene Derivatives; Amino Acids, Diamino; Benzenesulfonamides; Sulfonamides; Sulfones; Tamsulosin; Citrulline
• Other Study ID Numbers: FMBSUREC05052026BadawyCIT

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared because the study is an investigator-initiated single-center clinical trial and the informed consent does not include a specific plan for external individual-level data sharing. Only aggregated, de-identified study results will be reported. Any future sharing of de-identified individual participant data would require additional approval from the Research Ethics Committee.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No