Medical Expulsive Therapy (MET)

Medical Expulsive Therapy (MET) is a recommended treatment for patients with a reasonable chance of passing kidney stones. Although stones smaller than 3 mm have a high probability of passing naturally, MET is most useful for stones between 3-10 mm in size. However, many urologists suggest using MET treatment with alpha-blockers even for smaller or proximal stones to potentially avoid surgical intervention since the treatment is relatively inexpensive and has few side effects.

Observation is typically the initial treatment for acute stone episodes since spontaneous passage of the stone is common. The size and location of the stone can impact its passage, with stones smaller than 5 mm and those in the distal ureter having the highest chance of passing naturally. While most stones pass within 4-6 weeks, patients often experience a reduced quality of life during this period due to concerns about pain and hospitalization, as well as the economic impact of not being able to work.

Medical expulsive therapy, which uses medication to enhance the passage of stones or fragments, can reduce the potential time for stone passage in suitable patients, leading to significant benefits for both patients and the healthcare system. Alpha-blockers and calcium channel blockers have been shown to have a role in MET, but there are no clear guidelines on their use in initial conservative management or following definitive stone treatment.

During kidney stone treatment, patients should be aware of common symptoms such as nausea, vomiting, pain in the kidneys, abdomen, lower back, and sides, and blood in the urine. They should also be aware of common side effects such as lightheadedness, dizziness, and sinus congestion or runny nose sensation. For men, a decrease in ejaculate volume due to retrograde ejaculation may occur.

Small stones in the ureter and kidneys can pass out naturally with newly developed medicines. Most kidney stones do not require invasive treatment and can be managed through regular medication and adequate water intake. Drinking 1.9 to 2.8 liters of water a day can help flush out the urinary system. The doctor may also prescribe medication to relax the muscles in the urethra, making it easier and less painful to pass the kidney stone.