Medications to help pass kidney stones may not be effective

Kidney stonesIf you’ve recently experienced a kidney stone episode, there is a good chance that a medication such as tamsulosin or nifedipine may have been prescribed to help you pass your stone. These medications, originally designed for other purposes including treating high blood pressure and enlarged prostates, were thought to increase your chances of passing a ureteral stone by relaxing the muscles in the ureter.  This treatment is known as “medical expulsive therapy” and several dozen studies supported their use. A combined review of 32 studies by the Cochrane Collaboration found “a higher stone-free rate and a shorter time to expulsion” with these medications and the authors concluded that “alpha blockers should therefore be offered…as one the primary treatment modalities” for patients passing a ureteral stone.

A recently published large study from the UK has however demonstrated the opposite conclusion: these medications appear to be ineffective in helping stones to pass. The study, published in the Lancet by Pickard and colleagues in July of 2015, differed from previous studies in its size and thorough scientific design. 1,167 participants with ureteral stones measuring on average 4.5mm were randomly assigned to three groups. In each group, participants were given either placebo (sugar pill), tamsulosin, or nifedipine. The participants were then followed to see whether they passed their stone successfully. After 4 weeks, there were no differences seen, with 80% of those receiving placebo not needing further treatment, compared to 81% of those receiving tamsulosin and 80% of those receiving nifedipine. Pain scores, pain medication use, and time to stone passage also did not differ between the groups. The bottom line? These medications did not seem to improve your chances of passing a stone, nor did they reduce pain with stone passage. You can read the full original study at the Lancet’s website.

Why did the results of this study differ so significantly from prior studies? The most likely reason is the large size of the UK study and its design allowed for a more thorough evaluation of the potential benefits of these medications. Prior studies were small, involving in most cases a hundred or so patients. Small studies can be less accurate and to help combat their drawbacks, researchers sometimes pool the results of multiple smaller studies into one large study in a technique known as “meta-analysis”. This is how the Cochrane collaboration report mentioned above conducted their analysis. While this approach is helpful in many cases, one potential drawback is the risk for the results being influenced by “publication bias” – researchers tend to have better luck publishing studies that show a positive benefit while “negative” studies, which show no effect from a treatment, are less likely to published. These “negative” studies are therefore less likely to be available to be included in meta-analyses, skewing the results towards the published positive studies, potentially showing a benefit where there may not be one. The UK study additionally differed in other important ways from prior studies, including by not using repeat CT scans to assess stone passage. This is more similar to actual practice in the real world but it may be less accurate in assessing whether a stone has passed or not.

Future research on this topic may find that these medications or other medications may have some role in helping to pass stones in specific situations (such as in patients with larger stones) but for now, these new findings suggest that for most patients, using alpha blocker medications may not be beneficial in helping to pass a stone. If you find yourself in the unfortunate situation of trying to pass a stone and are offered this type of medication, talk to your healthcare provider to see if they feel you should still take them in light of these new findings.

About Dr. Mike Nguyen

Mike M Nguyen, MD, MPH, is a urologist and an Associate Professor of Clinical Urology at the Keck School of Medicine of USC in Los Angeles, CA. He specializes in the treatment of kidney stones with both surgery and dietary prevention and the in the treatment of kidney and prostate cancer using the latest robotic surgical approaches. He sees patients at clinics located in Los Angeles, Pasadena, and La Canada, CA. He is the founder of the www.KidneyStoners.org website.
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11 Responses to Medications to help pass kidney stones may not be effective

  1. Oscar Rubino says:

    holy shit this page has scared the shit out of me.i have a stone in my left kidney and i am terrorfied of what to expect.This can’t be easy.GOD HELP ME

  2. VanessaMD says:

    I cannot take the spasms with stents placed and my doctor prescribes Detrol LA AKA ditropan. Mind you it’s not a miracle drug but it does help me. It makes obviously intolerable pain and spasms tolerable for the most part. I see this was months ago for Michelle’s husband BUT I hope that maybe this info can help someone. I have passed over 200 stones up to 7mm in size. The most of them being approximately 5mm in size and WITHOUT pain medicine. After so many stones you would like to think that I would not ever have a doctor disbelieve me but despite always taking the stones to the actual Doctor that said I was not passing a stone they still act as though I’m merely seeking drugs. Most of the time I just suffer through it and hope for the best.

  3. Andy says:

    I have a question I have yet to see anywhere online. We are on well water at my house, water that’s filled with calcium deposits. Our coffee machine after a few months looks like it has oatmeal accumulated in it. My question is would these contribute to kidney stone formation? Since my last episode a week ago, I’ve since changed to only using purified or distilled water for coffee (and a lot of cranberry juice in lieu of sodas). Also, is there any benefit to using distilled water, as I seem to remember reading that it’s good for flushing minerals out of ur body.

    • Trish says:

      Cranberry juice is not good for you if you have mainly calcium oxalate stones. You must find out what kind of stones you mainly have.
      Cranberry juice helps UTIs , urinary tract infections.
      If you think this could help you, cranberry pills or capsules are better.
      These seem to be ok for calcium oxalate stone formers.
      Cranberry juice could contribute to the formation of new stones if you have calculated oxalate stones. there are 3 other kinds of stones too. Not everyone has thmostly that kind of stones. A stone must be given to a doctor and sent
      to a lab for analysis. Your body chemistry does change and that effects stone formation. Annual or more frequent lab work and 24 urine tests can be done to help you manage stone disease

  4. Sudheendra says:

    Are you sure there isnt a way to atleast induce sleep and allow the stones to pass? anything would help

    • Andy says:

      Closest I ever came to what ur asking is one of the first times my wife witnessed me go thru this, slumped on the bathroom floor, sweating head to toe, just finished vomiting, she pushed me in the car and rushed me to the ER. A male nurse there also suffered from kidney stones and showed me some mercy. Gave me a cocktail of meds in a shot that knocked me out for a few hours and kept the pain down for the next day. Gave me time to work on passing it (water, water and more water, plus a ton of cranberry juice 100% no sugar added, the awful tasting kind)

  5. Nick says:

    My Kidney Stone composition 97% calcium oxalate monohydrate 1% calcium oxalate dehydrate 2% calcium phosphate Help!

  6. Michelle Fraser says:

    Can anyone direct me to any advice for pain control after having a ureteral stent fitted? My husband is in so much pain he is frightened to drink liquid because of the terror of passing urine. I want to help him manage the pain – doctors have only given him paracetamol and ibroprofen (we’re in the UK) but it doesn’t even begin to dull the pain. It’s a frightening experience so any advice would be greatly appreciated.
    Many thanks,
    Michelle

    • darren young says:

      hello michelle, I can fully relate to your husband having suffered stones for over 30 years.the last ones I had were in 2014 and I had 3 stents put in place the only way of easing the pain is with a high dose of co codamal which can make you feel a little sick but they do help.
      another thing that helped me was controlling your breathing while passing water,holding your breath then let it out slowing always seemed to help the pain also you can try panting sound stupid but it does work.
      hopefully he has had the stent removed by the the time you receive this email but remember it for the future just in case
      kind regards darren

      • Andy says:

        I had one of my kidney stone episodes a week ago and I found when the pain became unbearable (as it eventually does), the breathing was helpful, if just to take ur mind off the pain as u focus on slow, deep breaths. My dad suffers from these as well and always told me to jump off the porch steps a few times to try and dislodge the stone. Never helped me much tho. Water is always ur friend in these times (tho this one seemed to block the tube so bad that no amount of water seemed to help me pee, just built up more pressure.)

    • Paul kirby says:

      I’m on paracetamol nefopan codine 4 times a day and brings the pain down to a level 5 oral morphine very 2 hours take the edge off I am having my stent out this Monday and can wait the pain is nearly as bad as the stones

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