Sridharan K et al, 2017: Medical expulsive therapy in urolithiasis: a mixed treatment comparison network meta-analysis of randomized controlled clinical trials.
Sridharan K, Sivaramakrishnan G.
School of Health Sciences, Fiji National University, Suva, Fiji Islands.
School of Oral Health, College of Medicine, Nursing and Health Sciences, Fiji National University, Suva , Fiji Islands.
BACKGROUND: Medical expulsive therapy (MET) using alpha blockers, calcium channel blockers (CCB), phosphodiesterase inhibitors (PDEI) and spasmolytics have been shown to be effective in clinical trials on urolithiasis. The present study is a network meta-analysis comparing the above mentioned drug classes.
RESEARCH DESIGN AND METHODS: Electronic databases were searched for randomized controlled trials comparing the above mentioned drug classes in patients with urolithiasis using appropriate search strategy. Inverse variance heterogeneity model was used for the mixed treatment comparisons. Stone expulsion rate (SER) was the primary and stone expulsion time (SET) was the main secondary outcome measure.
RESULTS: We included a total of 114 studies for systematic review and 108 studies for the network meta-analysis. Alpha blockers, PDEI, and combined alpha blockers and corticosteroids had significantly increased SER and shorter SET than placebo or standard of care. Alpha blockers have the highest probability of being the 'best' in the pool with regard to SER. This effect persisted in patients with stones ≥ 5 mm, children, after shockwave lithotripsy, proximal ureteric stones and distal ureteric stones.
CONCLUSION: To conclude, we observed a statistically significant increase in the expulsion rate and shorter expulsion time with alpha blockers, PDEI and combined alpha blockers with corticosteroids. Of these interventions, alpha blockers have the high probability of being the 'best'.
Expert Opin Pharmacother. 2017 Aug 4:1-11. doi: 10.1080/14656566.2017.1362393. [Epub ahead of print]
This meta-analysis includes 9 studies published in 2012, 14 in 2013, 15 in 2014, 18 in 2015, 14 in 2016. The authors state: from the year 2011, addition of data did not have any significant drift in the pooled estimates for SER and similarly from the year 2014 for SET.”
Obviously the alpha-blocker story goes on and on and on … but without a gain of information. Readers should not waste time on reading original papers and meta-analyses on that topic.
The authors justify their publication by pointing out the unique character of their technique:
“Use of MET in urolithiasis has been debated for more than a decade. Many randomized controlled trials were conducted comparing the interventions and similarly meta-analyses pooling the results from such randomized controlled trials. This is the first NMA evaluating MET in urolithiasis. A NMA offers the advantage of comparing multiple interventions through a direct and indirect approach using a common comparator. To discuss with a simple example, when there are three treatment arms, A, B, and C, and when head-to-head trials have been conducted only between A and B and B and C, indirect comparisons between A and C can be made through the common comparator B. By doing so, it may be possible to identify the best amongst a basket of agents that can be used for treating a particular disease in case of limited clinical evidence.”
Nevertheless the conclusion sounds very familiar to me: “The quality of evidence is moderate for the recommendations pertaining to alpha blockers and very low for other drugs used in MET.”