Kidney stones affect 8.8% of the population according to the most recent National Health and Nutrition Examination Survey. Symptoms include pain in the side of the abdomen or back, pain that comes in waves of fluctuation intensity, red or brown urine, and nausea and vomiting to name a few. Routine outpatient care includes oral hydration, anti-nausea medication and pain medications. Other medications can also be included to help the expulsion of the stone if it is < 10mm in size. The two medications commonly used to help pass stones and reduce pain are Tamsulosin (Flomax) or Nifedipine. A new study showed that these medications may be no better than placebo.
It is called the SUSPEND (Spontaneous Urinary Stone Passage Enabled by Drugs) trial. It is a multi center randomized control trial designed to determine the effectiveness of Tamsulosin or Nifedipine for patients aged 18-65 with a single stone measuring < 10mm as seen on a CT scan. Over 1000 adults were randomized to take Tamsulosin (0.4 mg/day), Nifedipine (30 mg/day) or placebo for 4 weeks or until the stone spontaneously passed. The primary outcome was to determine how many participants spontaneously passed their stone. Secondary outcomes looked at how long it took to pass the stone and differences in pain.
The results showed that the proportion of people that passed their stone was no different with either medication group or placebo. There was also no differences between the medication groups and placebo in the time it took to pass the stone as measured by clinical report and confirmed by CT scan. The average number of days to pass the stone in all the groups was 15 days. Self reported use of pain medication during the first 4 weeks was also similar between the groups. The average use of pain medication used was 10-11 days.
There was no evidence that gender, stone size (< 5mm vs > 5mm) or stone location impacted the efficacy of treatment.
So even though your practitioner may still offer a medication to help expel your kidney stone if it is less than 10mm in size, it may not have any additional benefit in length of time of stone expulsion or pain.
Slattengren, A et al. “Kidney Stones? It’s Time to Rethink those Meds”. Clinician Reviews. April 2016, pp, 20,44.