Medical Expulsive Therapy for Ureteric Stone

Q: What is medical expulsive therapy (MET) for ureteric stones?

MET uses oral alpha blockers (e.g., Tamsulosin) to relax ureteral smooth muscle and facilitate spontaneous stone passage. It is suitable for stable patients with no sepsis, no kidney failure, and adequate pain control, with stones of appropriate size and location.

Q: What are the success rates for ureteric stones to pass with MET?

Spontaneous passage: 68% for <5mm stones, 47% for 5-10mm. Lower ureter: 75%, upper ureter: 48%. MET increases passage rate by ~29% per US/European guidelines.

Q: When is medical expulsive therapy not appropriate?

MET is contraindicated with urosepsis, acute kidney failure from obstruction, or uncontrolled pain. These require urgent endoscopic intervention (ureteroscopy or ureteric stenting) instead.

Last updated: May 18, 2026

Soarawee Weerasopone, Urologist

Bangkok hospital Headquarter, Bangkok

Samitivej Sriracha hospital, Chonburi

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It is very common for me to care for ureteric stone pain patients who have frequent questions about medical expulsive therapy (MET) for ureteric stones. Here are the answers in Q&A format.

Urology center Bangkok hospital Thailand Booking online 02-310-3009 bhquro@bdms.co.th
Samitivej Sriracha hospital Chonburi 088-022-1445

Q: Is it possible to avoid endoscopic stone surgery?

Yes, it is possible — but only if all of the following emergency conditions are absent:

Pain is adequately controlled by pain medication
No sign of kidney failure from stone obstruction
No signs of life-threatening bloodstream infection (urosepsis)

Medical expulsive therapy may help avoid emergency endoscopic stone removal.

Q: How likely is a ureteric stone to pass spontaneously without medication?

It depends on the size and location of the obstructing stone:

By size: 68% for stones <5 mm; 47% for stones 5–10 mm
By location: 48% for upper ureter; 60% for mid-ureter; 75% for lower ureter

Chance of passing a stone depends on size and location in the ureter.

Q: How much does medical expulsive therapy improve the stone passage rate?

According to US and European urological guidelines, medical expulsive therapy (typically alpha blockers such as Tamsulosin) increases the stone passage rate by approximately 29% compared to no medication.

Q: Are there any side effects of medical expulsive therapy?

There is a chance that ureteric pain may temporarily worsen as the medication facilitates stone movement. Approximately 4% of patients experience side effects including dizziness, headache, nausea, and vomiting.

4% dizziness reported during medical expulsive therapy.

Q: What parameters are used to assess stone passage success?

Several CT-based parameters are assessed: transverse stone diameter, longitudinal stone diameter, ureteral diameter at the stone level, and stone-to-bladder distance. These help the urologist select the right patients for medical expulsive therapy vs. early endoscopic intervention.

After carefully assessing the ureteric stone on CT scan, the urologist can select the appropriate patients for medical expulsive therapy.

During the treatment period, I schedule regular follow-up visits with at least an ultrasound to check whether the stone is moving downward. Important: Do not take MET medications on your own without medical supervision, as serious complications can arise without proper monitoring.

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Frequently Asked Questions About Ureteric Stone Medical Expulsive Therapy

What is medical expulsive therapy (MET) for ureteric stones?

Medical expulsive therapy (MET) is the use of oral medication — typically alpha blockers such as Tamsulosin — to relax the smooth muscle of the ureter, facilitating spontaneous passage of a ureteric stone without surgery. It is suitable for patients who are clinically stable (no sepsis, no kidney failure, adequate pain control) and who have stones likely to pass based on CT assessment of size and location.

What are the success rates for ureteric stones to pass with MET?

Without medication, the spontaneous passage rate is 68% for stones under 5 mm and 47% for stones 5–10 mm. Lower ureteric stones have a 75% spontaneous passage rate compared to 48% for upper ureteric stones. Adding medical expulsive therapy increases the overall passage rate by approximately 29% based on US and European guidelines, making it a meaningful adjunct to conservative management.

When is medical expulsive therapy not appropriate?

MET should not be used when there are emergency indications for immediate intervention: urosepsis (life-threatening urinary infection), acute kidney failure from bilateral obstruction or single kidney obstruction, or pain that cannot be controlled with medication. In these situations, urgent endoscopic intervention (ureteroscopy or ureteric stenting) takes priority over conservative management.

If you have ureteric stone pain and would like a specialist evaluation, Dr. Soarawee Weerasopone offers specialist consultations at Bangkok Hospital Headquarters. Book a Consultation.

Disclaimer: This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters. It is intended for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any medical treatment.

Medically written & reviewed by: Dr. Soarawee Weerasopone (Dr. Pom) — Board-Certified Urologist, Bangkok Hospital Headquarters. International Fellow: Baylor College of Medicine (USA) · Juntendo University (Japan) · Chang Gung Memorial Hospital (Taiwan).

Dr. Soarawee Weerasopone

Dr. Soarawee Weerasopone (Dr. Pom) is a board-certified urologist at Bangkok Hospital Headquarters, specializing in Men’s Health, Robotic Surgery (Da Vinci System), and Kidney Stone treatment. He has completed international fellowships at Baylor College of Medicine (USA), Juntendo University Hospital (Japan), and Chang Gung Memorial Hospital (Taiwan). All medical content on this site is written and reviewed by Dr. Soarawee based on his clinical experience and international training.