How Does Flomax Work for Kidney Stones?

The sudden, intense pain of a kidney stone will have you searching for a way to pass your stone — fast. The National Kidney Foundation estimates that one in 10 adults will experience a kidney stone at some point in their life and over 500,000 cases of kidney stones are seen in hospitals each year. Among other methods to help you pass a kidney stone, many doctors are turning to a process called medical expulsive therapy (MET) with the use of tamsulosin, or Flomax, to help pass the stone easier and quicker, according to a 2018 article published in the Journal of Family Practice.

What is Flomax?

Flomax, an alpha-blocker, is a commonly prescribed medication for men with benign prostatic hyperplasia, or an enlarged prostate. An enlarged prostate can cause urinary issues, such as urinating often, a weak stream, or not being able to empty the bladder, according to the Mayo Clinic. Flomax relaxes the muscles of the bladder neck and prostate, making it easier to urinate. Tamsulosin does not make the prostate smaller, it only treats the symptoms of the enlarged prostate. Flomax is taken as a capsule by mouth.

Types of Kidney Stones

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Kidney stones are small pebbles in your kidneys usually made up of minerals that reach high levels in your urine. The National Kidney Foundation indicates the two most common types of kidney stones are calcium oxalate stones and uric acid stones 1. Uric acid stones can be formed when there is a high level of purines in the diet. Purines are high in organ meats and shellfish.

Calcium oxalate stones are usually caused by dehydration, or low fluid levels, and low calcium intakes. Calcium in the diet can help bind to oxalate and remove it before it gets to the kidneys. The National Kidney Foundation states that individuals with low dietary calcium intakes are at high risk for kidney stones 1.

Symptoms of Kidney Stones

The National Kidney Foundation stresses that the size of the stone, whether it be the size of a grain of sand or larger, will have a large impact on the symptoms associated with the stone 1. Symptoms include intense pain on either or both sides of your lower back, nausea, vomiting, stomach pain, fever, chills, blood in the urine, or urine that smells bad.

How Flomax Works for Kidney Stones

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Flomax is intended to ease the flow of urine associated with BPH. It is now being used, although still infrequently, to ease the passage of kidney stones through the urinary tract. Alpha-blockers, like Flomax, help dilate the urinary system to help pass a kidney stone at a quicker pace, according to 2018 review article published in Journal of Pharmacy Technology.

The 2016 American Urological Association guidelines for the management of stones indicates that alpha-blockers may be beneficial for stones that are less than 10mm 6. They indicate that many smaller stones may pass on their own, but with the safety record of alpha-blockers, it may speed up the passing of stones.

The research; however, is not conclusive on the use of tamsulosin in the treatment of kidney stones 37. Recent research published in the Journal of the American Medical Association concluded that tamsulosin was not effective in increasing the passage time for stones less than 9mm when compared with placebo 239.

Dietary modifications are also recommended to speed up the passing of kidney stones. Drinking plenty of water, decreasing sodium intake, and decreasing animal protein in the diet are advised, according to the authors in Journal of Pharmacy Technology.

Can Women Take Flomax?

Most of the research with tamsulosin has been conducted on men, most likely because it is not approved for use in women by the FDA 347. One specific study, called the SUSPEND study — Spontaneous Urinary Stone Passage ENabled by Drugs — included women in their study. When looking at the rate and time of passage of stones in comparison with medication or placebo, they did not find a difference.

These study findings, published in the Journal of Family Practice in 2016 may indicate the need for a conversation with your primary physician when considering tamsulosin for treatment of kidney stones 238.

Side Effects of Flomax

There is the potential to be allergic to Flomax. The U.S. National Library of Medicine indicates side effects can include skin rash, extreme itching, and respiratory symptoms 4. If experiencing any adverse reaction to Flomax, stop using immediately and seek medical attention.

There have also been side effects reported with tamsulosin 310. According to the Mayo Clinic, common side effects are fever and chills, lower back pain, cough, and difficulty urinating 310. Less common or rare side effects are chest pain, fainting, dizziness, sensation of spinning or orthostatic hypotension — feeling lightheaded when standing from a seated position.

Precautions When Taking Flomax

Individuals who are allergic to sulfa drugs, which treat a wide variety of conditions, should use caution when taking Flomax. In addition, those who have low blood pressure should speak with their doctor, because taking this medication could make the condition worse, causing dizziness and fainting. If you have severe liver or kidney disease, you should not take Flomax, warns the Mayo Clinic 310. These conditions could affect the way the medication is removed from the body.

Flomax has the potential to interfere with a large number of medications to include warfarin and vasodilators, so it is imperative to speak with your doctor about any current medications you may be taking.

Prevention of Kidney Stones

If you are trying to prevent a single occurrence of a kidney stone or reduce the chances of developing another stone, there are some lifestyle modifications to consider.

• Pay attention to urine color — the darker the urine, the more dehydrated you are. Drink plenty of fluids to constantly flush fluids out of your kidneys to help prevent minerals from depositing there. The National Kidney Foundation recommends at least 12 glasses per day and more if you are out in the heat. 
  
• Eat plenty of fruits and vegetables 1. Diets high in animal protein may produce more acid in the urine, increasing the chance for stones. Fruits and vegetables are high in water, which can help flush out the kidneys. 
• Reduce the amount of salt in your diet. Higher amounts of sodium in the body can increase the chance of developing a kidney stone. 

When to See a Doctor for Kidney Stones

If you are experiencing any of the above symptoms, seek immediate medical attention. If you are actively passing a stone and can save a piece of the stone, that may be helpful for a doctor. Knowing the type of stone can help in modifying your diet, if possible, to prevent a reoccurrence of another stone.

Your doctor will immediately want to see where and how big the stone is, so you will most likely receive a computed tomography (CT) scan or an x-ray for diagnostic purposes. Based on the diagnostic data and the health of your kidneys, you and your doctor will decide on a treatment plan to pass or destroy the stone. Your doctor may recommend a visit with a registered dietitian, who can look at your diet and make sure you make the necessary changes to your daily eating plan.