Whether or not medical expulsive therapy (MET) is a sound recommendation for patients with kidney or ureteral stones is a matter of debate. MET still has a role in the management of some patients, according to AUA guidelines for the management of ureteral calculi. But a large, multicenter study in The Lancet (2015; 386:341–9) found no evidence supporting the use of MET with the alpha-blocker tamsulosin or the calcium channel blocker nifedipine. The lead author of that study told Urology Times that, based on the results, these drugs should no longer be recommended or used to reduce the risk of intervention required to remove stones in people with ureteric colic.
So, what is a urologist to do? We asked two experts in stone disease to answer the important questions regarding MET use in this patient population. The experts are Stephen Y. Nakada, MD, professor and chairman of urology at the University of Wisconsin School of Medicine and Public Health in Madison, and Glenn M. Preminger, MD, professor and chief of urologic surgery at Duke University Medical Center, Durham, NC.
Dr. Preminger helped to write the AUA’s guidelines on ureteral calculi management. Neither physician has conflicts of interest related to this topic.
Why the recent controversy?
In a recent study, researchers at the University of Michigan Medical School reviewing 55 kidney stone studies found moderate evidence to support use of alpha-blockers for larger stones (≥5 mm). Published online Dec. 1 in The BMJ, first author John M. Hollingsworth, MD, said that The Lancet’s results prompted the researchers to study 1,136 subjects in the United Kingdom.
Why the discrepancy with these and other studies? Dr. Nakada thinks that while the therapeutic benefit of MET may be in question, the varying designs of the studies, including different endpoints, might also contribute to the variable nature of the findings.
Dr. Preminger said the use of varying endpoints is the primary reason for the diversity of MET study outcomes.
“When they determined whether the treatment was successful or not, the study in The Lancet used intention to treat as their endpoint… as opposed to many other studies that performed imaging studies to specifically document whether or not the ureteral stone was still present. Many argue that The Lancet study was flawed because they never definitively proved whether or not the stone had passed,” Dr. Preminger said.