Combination therapy only shows short-term superiority over monotherapy on ureteral stent-related symptoms – outcome from a randomized controlled trial
Liu et al. BMC Urology
Combination therapy only shows short- term superiority over monotherapy on ureteral stent-related symptoms - outcome from a randomized controlled trial
Qinyu Liu 0
Banghua Liao 0
0 Equal contributors Department of Urology, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University , Chengdu 610041, Sichuan , People's Republic of China
Background: Controversy remains on the superiority of combination therapy over monotherapy on ureteral stent-related symptoms (SRSs). We tend to explore if there is a necessity of combination therapy. Methods: One hundred cases of unilateral upper urinary tract calculi with stent insertion (pre and post flexible ureteroscopy) were randomized into 4 groups, given non-treatment, solifenacin, tamsulosin or combination respectively. Eight times of follow-ups were given after each insertion. Results: SRSs released spontaneously within 4 days after insertion (p = 0.017) but then stay with no further improvement. Benefit of solifenacin on flank pain started showing after day4 (p = 0.002), which was comparable to that of tamsulosin and combination (p = 0.914 vs 0.195). Combination therapy showed superiority over both monotherapy before day4, but after then solifenacin and tamsulosin showed similar effectiveness with the combination therapy on both bladder pain (p = 0.229 vs 0.394) and urgency (p = 0.813 vs 0.974). No improvement on hematuria or frequency was observed in each group. Conclusions: Combination therapy takes effect faster but shows no supervisory after the first few days compared with monotherapy. Trial registration: The study protocol was registered on Chinese Clinical Trial Register on April 17th, 2013 (registration number: ChiCTR-TRC-13003148).
Stent-related symptoms; Medication therapy management; Muscarinic antagonists; Adrenergic alpha-1 receptor antagonists
A vast majority of patients with indwelling ureteral stent
are suffering from stent-related symptoms (SRSs) with
poor quality of life (QoL), and storage symptoms and body
pain are the most troublesome [1, 2]. Currently it is
hypothesized that bladder discomfort, lower urinary tract
symptoms (LUTS) and hematuria are due to mechanical
irritation of bladder trigone as well as bladder neck, while
flank pain is associated with vesicoureteric reflux and
evidences showed antireflux stent can minimize the pain .
As a consequence, efforts such as improving stent design
and composition and investigating medical therapy have
been made to solve this problem [4–6]. So far many
researches have shown that α-blockers and anticholinergic
agents both can ease these discomforts and ultimately
improve the QoL  . However, there’re still not many
researches on comparison between monotherapy and
combination. In addition, some most recent published
papers made different voices: while former researches
with International Prostate Symptom Score (IPSS) found
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combination therapies provided preferable outcomes,
some most current ones declared that monotherapies
functioned equally with the combination in Ureteric
Stent Symptom Questionnaire (USSQ) assessment [8, 9].
Basing on the background above, we conducted a
randomized controlled trial to evaluate the efficacy of
solifenacin, tamsulosin and the combination therapy, and
meanwhile to explore SRSs’ development features with
time as secondary outcomes.
Subjects and treatments
An open-label, randomized, controlled study was
conducted at West China Hospital of Sichuan University
from Feb 2014 to May 2015. Inclusion criteria were as
followed: (1) aged 18–60 years with unilateral
nephrolithiasis ≤2 cm; (2) 4.7Fr ureteral stent being inserted
before and after flexible ureteroscopic lithotripsy. The
exclusion criteria included: (1) a history of urinary tract
surgery; (2) a history of LUTS related to benign prostatic
hyperplasia or infection; (3) concomitant use of other
antiadrenergics, anticholinergics, and analgesics; (4) a
history of neurogenic bladder, overactive bladder syndrome,
neurologic and psychiatric diseases, chronic prostatitis and
urinary tract abnormalities; (5) drug allergy; (6) having
major complications after the surgery.
4.7Fr ureteral stents (INLAY®, Bard Inc.) of 26 cm were
inserted in all cases through cystoscopy 2 weeks before
the ureteroscopic surgery. A stent of the same size was
inserted after lithotripsy under general anesthesia within
the flexible ureteroscopic surgery. X-ray plain films were
done after both insertions to make sure the stents were in
correct position since inappropriate stent location would
worsen LUTS and affect the QoL severely [10, 11].
Patients were told to drink more than 2500 ml water per day
and avoid aggravating physical activities after insertion.
Patients were discharged on the third day following
Randomization, follow-up, assessment of outcomes
Patients were randomized into one of four groups, namely
C (control), S (solifenacin 5 mg once daily), T (tamsulosin
0.2 mg once daily), and S + T (solifenacin and tamsulosin
Follow-ups were performed on day 1, 2, 3, 4, 5, 6, 10,
and 14 after stent insertion on phone. Questions on
urinary symptoms were selected from USSQ to assess
bladder irritation, while a visual analogue scale (VAS)
and a seven-score QoL scale were adopted for body pain
and QoL assessment. Every patient had two series of
follow-ups (pre- and post-lithotripsy) as self-control. Data of
patients who missed more than twice dose or follow-ups
throughout the follow-up duration were excluded in the
final analysis. Also a questionnaire aiming at adverse
events was taken on day14 to evaluate the safety.
The primary outcome was the urinary symptom score
of the given questionnaire. The secondary outcomes
included scores in every single symptom assumed in
the current study, the score of quality of life and initial
Sample size and statistical analysis
Sample size was calculated with the standard deviation
of the urinary symptom domain of 4 as observed in our
preliminary test of patients given no treatment and the
following assumed post-stent urinary symptom scores:
no treatment (14), tamsulosin (11), solifenacin (11)
tamsulosin, and solifenacin (10). For α = 0.05 and β = 0.1, the
minimal sample size needed for each group was 20.
Assuming a 20% withdrawal rate, we decided to have 25 as
the least sample size needed for each group and recruit
as many as possible during the research period.
SPSS 20.0 was used for statistical analysis. Repeated
measures analysis of variance was used to compare
variables between groups. Chi-square and ANOVA tests were
used to compare ratios and mean values between groups
or different follow-up days. Logistic regression was used
to reveal relevance between variables. A p-value < 0.05
indicated statistically significant differences in the current
Finally, a total of 112 cases were recruited. With 12
cases (10.71%) not appropriate for final analysis due to
loss of follow-up or poor compliance, the final sample
size was 100 (group C 28, S 26, T 22 and S + T 24, Fig. 1).
No significant differences showed in age, height, weight
or gender among the 4 groups (p = 0.633, 0.131, 0.674,
0.337) (Table 1). None of participants were found with a
history of urinary tract surgery, LUTS related to benign
prostatic hyperplasia or infection, concomitant use of
other similar drugs or any other comorbidities that may
confuse the assessment of SRSs.
Characteristics of SRSs in the control group
Outcomes from the group C showed that the total score
of all symptoms spontaneously decreased in the first
4 days (from 12.75 ± 3.52 to 9.93 ± 3.64, p = 0.017).
However after that, no significant differences showed from
day4 to day14 (from 9.93 ± 3.64 to 9.18 ± 3.38, p = 0.602),
and a trend of increase was noted after day6 (Fig. 2).
Though the degree of symptoms changed over time,
score of quality of life stayed relatively steady throughout
the follow-up (p = 0.674) and the minimal score was
3.25 ± 1.08 (score3 means mostly satisfied while score4
means about equally satisfied and dissatisfied) (Additional
file 1: Figure S1).
Fig. 1 Flow diagram of the current study
Effect of endoscopic procedure on SRSs
Generally no significant differences were found in total
scores of symptoms between pre- and post-lithotripsy
cases (p = 0.066). However, subsection analysis showed
that pre-lithotripsy cases had lower scores than those of
post-lithotripsy ones before day4 (p = 0.001, mean
difference = −1.455, 95% CI = −2.334 to −0.576). Subgroup
analysis of single symptom suggested that within the first
4 days following insertion, pre-lithotripsy cases had milder
bladder area pain (p = 0.036, mean difference = −0.39, 95%
CI = −0.75 to −0.03), flank pain (p = 0.005, mean
difference = −0.60, 95% CI = −1.01 to −0.19) and hematuria
(p = 0.001, mean difference = −0.065, 95% CI = −0.34 to
−0.09) comparing to post-lithotripsy cases. Pre- and
postlithotripsy cases had similar level of frequency (p = 0.232)
and urgency (p = 0.825) from the beginning to the end
(Additional file 1: Figure S2).
Efficacy outcomes of medication therapy
Overall, solifenacin, tamsulosin and combination therapy
group all had lower levels of SRSs than the control group
throughout the follow up (p = 0.004 & 0.026 & <0.001).
Table 1 Popularity characteristic of the current study
Age (year), mean ± SD
Height (cm), mean ± SD
Weight (kg), mean ± SD
P < 0.05 for age, height, weight and gender among the 4 groups
Before day4, combination therapy provided even lower
scores of SRSs than single solifenacin (p = 0.016, mean
difference = −1.52, 95% CI = −2.76 to −0.29) and tamsulosin
(p = 0.002, mean difference = −2.10, 95% CI = −3.39 to
−0.81), but no significant differences showed up between
combination and either single drug group after day5
(solifenacin & tamsulosin, p = 0.84 & 0.77). Solifenacin
and tamsulosin showed comparable effect throughout
the whole follow up (p = 0.582) (Fig. 3).
As for specific symptoms, no statistical differences
were found in flank pain scores among all 4 groups
before day4 (p = 0.101). However, from day5 to the end, a
superiority over the control group was noted in
solifenacin group (p = 0.002, mean difference = −0.71, 95%
CI = −1.14 to −0.27), which was comparable with
tamsulosin and combination therapy (p = 0.914 vs 0.195).
Combination therapy released bladder pain and urgency
from the very beginning and remained effective to the end
(comparing with the control, bladder pain p < 0.001, mean
difference = −1.07, 95% CI = −1.43 to −0.72; urgency
p < 0.001, mean difference = −0.61, 95% CI = −0.91 to −0.31).
On the other hand, neither of solifenacin or tamsulosin
Fig. 2 Means of total scores of all symptoms in control group on each follow-up day. The means changed statistically over time (p < 0.001) and
decreased obviously in the first 4 days (p = 0.017). However, from then on no significant differences showed from day4 to day14 showed (p = 0.602)
Fig. 3 Solifenacin, tamsulosin and combination therapy all released SRSs comparing to the control group (p = 0.004 vs 0.026 vs <0.001).
Combination therapy could release the SRSs much faster than solifenacin (p = 0.016) or tamsulosin (0.002) in the first 4 days. No significant
differences showed up between combination and solifenacin (p = 0.842) or tamsulosin (p = 0.774) alone from day5 to day14. Solifenacin and
tamsulosin showed comparable effect throughout the whole follow up (p = 0.582)
showed significant effects on bladder pain (vs control,
p = 0.589 & 0.936) or urgency (vs control, p = 0.806 &
0.729) before day4. But from the fifth day on, solifenacin
and tamsulosin monotherapy both started showing equal
benefic effects as the combination therapy on both bladder
pain (p = 0.229 & 0.394) and urgency (p = 0.813 & 0.974)
Solifenacin, tamsulosin and combination group all
showed no superiority over the control group in hematuria
(p = 0.736 & 0.924 & 1.000) or frequency (p = 0.073 & 0.860
& 0.092) (Additional file 1: Figure S3). Incontinence was
observed on only two follow-up days from one single case
in solifenacin group.
As for quality of life (QoL), significant difference
existed among the 4 groups (p = 0.046) but combination
therapy wasn’t superior to either monotherapy group
(solifenacin and tamsulosin, p = 0.107 vs 0.670).
Medication therapy groups had higher scores than the control
at the beginning but finally went down to be lower after
day4 (Additional file 1: Figure S4).
Fig. 4 Means of scores of flank pain (a), bladder pain (b) and urgency (c). Effect on flank pain started showing up from day5 to the end (p = 0.006) and
solifenacin is comparable to tamsulosin and combination therapy (p = 0.914 vs 0.195) (a). Combination therapy released bladder pain and urgency
throughout the whole follow-up (comparing with the control, both p < 0.001) (b and c). Before day4, Solifenacin and tamsulosin had no significant
effect on bladder pain (p = 0.589 vs 0.936) or urgency (p = 0.806 vs 0.729) but both showed showed comparable effectiveness as the combination
therapy from day5 to day14 (b and c)
Main complications of drug therapy groups were as
followed: solifenacin group with three patients with dry
mouth (3/26, 11.5%); tamsulosin group with two with
dizziness (2/22, 9.1%), combination group with three
with dry mouth and one with both symptoms in group
(4/24, 16.7%). The total incidence rate of adverse events
from these three groups and no significant differences
(p = 0.727). No serious adverse events were reported
throughout the study.
In a previous study on SRSs features, J. Irani et al. 
declared that the general tolerance to SRSs remains
unchanged with time while only some symptoms
significantly improve, dysuria and hematuria included. And
in the current study, we also recorded that though SRSs
relieved spontaneously to some degree within a few
days after the insertion, it would stay relatively stable
after then, and might even relapse or worsen as time
went by. The minimal total symptom score was
designed as 4, which meant suffering no SRSs, in our
questionnaire. But the actual minimal mean of total
scores of all symptoms in the control group was 8.607,
which again demonstrated that patients would not
develop complete tolerance to SRSs within two weeks.
We estimate that the symptoms appearing within the
very first days after insertion may be also associated
with stimulation of transurethral endoscopic
procedures, and these parts of symptoms can rapidly
improve. The phenomenon that pre- and post-lithotripsy
cases suffered differently in the beginning may support
this hypothesis to some degree. And since the patients
suffer the most in the first few days, we recommend
that active managements should be given to patient
right after stent-insertion, especially to whom following
Speaking of efficacy, solifenacin and tamsulosin showed
comparably promising effect on releasing urgency, bladder
discomfort and flank pain. And the long-term effects of
both monotherapies were not inferior to the combination
therapy in the current study. Meanwhile however, we also
noticed that in the first few days a combination therapy
would take effect faster than monotherapy, especially on
symptoms of bladder pain and urgency. We think that the
inhibitors of α- receptor and m-receptor may have
synergistic effect on releasing irritative symptoms of bladder. So
for patients who have relatively severe SRSs from the
beginning or who are urge to release the symptom, a
combination therapy is recommended. But after the
first few days, an alternation to monotherapy would be
a proper choice because the outcome demonstrated that a
long-term combination therapy was unnecessary.
Although some transient relieving was observed, no
general improvement in hematuria and frequency was
found in any medication therapy groups comparing with
the control, which disagreed with some previous studies
[13–15]. Hematuria is believed to result from mechanical
injury on mucosa by stent, so we think it may be more
likely to be affected by patients’ living habits, exercise
habits for example, other than medicine intervention. And
for frequency, we believe water-drinking amount also
contributes a lot to it apart from stent insertion. In the
current study, a daily water intake over 2500 ml resulted
in urine volume increasing to about 2000 ml per day.
Medication of α-blockers and anticholinergic agents are
believed able to release irritating-induced storage
symptoms while not affect the normal voiding function of
bladder [16, 17], so frequency resulting from increased urine
volume wouldn’t be improved by solifenacin or
tamsulosin. This reminds us that recording daily urine volume
may be necessary for an accurate SRSs assessment.
We found it interesting to note that QoL might not
improve completely with symptom releasing. On the
days just following stent-insertion, patients accepting
drug therapies had even poorer score on QoL than the
control, although the degrees of their symptoms were
about the same or even better. Not satisfied with the
slow effect of drug in the first few days may be one of
the reasons. Also our advice on water drinking and
exercise limitation, which may contribute to the lower
incidence of hematuria and flank pain, may also make
patients feel bothered. During the follow-up days some
patients complained about change in living habits and
their QoL scores stayed low even though they have no
There are three previous studies adopting the same or
similar regimen with the current study. Essam S. et al.
found combined therapy of 0.4 mg tamsulosin and
10 mg solifenacin daily significantly alleviated irritative
symptoms associated with stent-insertion comparing to
either single medication . Lim KT. et al. drew a
conclusion of agreement with Essam S. with half the dose
. Jinsung P. et al. adopted the same regimen of Lim
KT., but resulted in a totally different conclusion. They
declared that neither tamsulosin nor solifenacin
medications provide beneficial effects for SRSs . In the
current study, we conducted a multiple follow-up on
several different days to explore SRSs, which can avoid
bias of single-day follow-up adopted by the previous
studies since SRSs may be affected by aspects like
amount of exercise and water-drinking. All the
researches mentioned above reached only one agreement
that the administration of solifenacin and tamsulosin as
well as their combination appeared equally safe and no
severe complications were recorded. And so did the
The following limitations should be acknowledged. A
major one was that our method inevitably increased the
workload of follow-up staffs and participants, so a
limitation existed in comprehensiveness of symptom
assessment and sample size. However since the size reached
our established goal, we still believe our outcomes can
make some sense. Another problem was that our center
only provided stents with the same size and couldn’t
adjust the lengths of stents with heights. But while the
randomized groups had no significant difference in patients’
heights, this limitation would have little influence on the
comparison outcomes. Further studies may take more
comprehensive symptoms and effects of living habits into
account, ending in more accurate assessment of SRSs, so
as to bring out a more optimal protocol which can benefit
patients the most.
As our outcomes demonstrated, SRSs would release
spontaneously to some degree in the first few days after
the insertion, then stay non-improved or even worsen
in the following days, which may still be troublesome.
Combination of solifenacin and tamsulosin can take
effect faster and improve the SRSs better than
monotherapy in the first few days. After that, combination and
monotherapy relieve the SRSs equally. So for long-term
using, patients with SRSs may get comparable benefits
from monotherapy and combination. Patients with
frequency or hematuria may benefit little from both drugs
because these symptoms would be largely affected by
living habits. Further studies with lager sample size are
expected to collect more detailed data and drawing more
Additional file 1: Figure S1. Means of total scores of quality of life on
each follow-up day. No significant difference existed from day1 to day14
(p = 0.674). Figure S2. Means of Symptom scores of pre- and post-lithotripsy
cases. Generally pre- and post-lithotripsy cases had no significant differences
in total scores of all symptoms (p = 0.066) but subsection analysis showed
significant difference existed before day4 (p = 0.001) (a). Subgroup analysis
demonstrated difference in scores of bladder area pain (p = 0.036), kidney
area pain (p = 0.005) and hematuria (p = 0.001) (b, c, d). No obvious
difference showed up on frequency (p = 0.232) and urgency (p = 0.825)
from the beginning to the end. (e, f). Figure S3. Solifenacin, tamsulosin
and combination group showed no superiority over the control group
on hematuria (p = 0.736 vs 0.924 vs 1.000) (a). Solifenacin, tamsulosin and
combination therapy didn’t effectively release the level of frequency
(p = 0.073 vs 0.860 vs 0.092) (b). Figure S4. Mean of scores of quality of
life. Significant difference existed among the 4 groups (p = 0.046) but
combination therapy wasn’t superior to either single drug group (solifenacin
and tamsulosin, p = 0.107 vs 0.670). (DOCX 807 kb)
The current study was supported by the following funds: Technology
Support Plan of Science and Technology Department of Sichuan Province
(Grant No. 2014SZ0210), Foundation of Sichuan University for Outstanding
Youth (Grant No. 2014SCU04B21), Foundation for Academic Leader Fostering
of Personnel Department of Sichuan Province (Grant No. JH2014053), Key
Project for Applied Research of Organization Department of Sichuan
Provincial Party Committee (Grant No. JH2015017) and Natural Science
Foundation of China (Grant No. 81470927).
Availability of data and materials
The datasets analyzed during the current study is available from the
corresponding author on reasonable request.
QL and BL contributed equally to this work and share the co-first authors.
QL, KW and BL designed the experiments; QL, BL and RZ collected the data.
RZ and LZ analyzed while QL, TJ and KW interpreted the data. QL, BL, RZ
and LZ wrote the manuscript while DL, TJ, JL and KW provided suggestions
for revision. KW and HL obtained the funding. KW and HL did the supervision
job throughout this study. All authors read and approved the final manuscript.
Ethics approval and consent to participate
The study protocol was registered on Chinese Clinical Trial Register on April
17th, 2013 (registration number: ChiCTR-TRC-13003148) and was approved
by Ethics Committee of West China Hospital of Sichuan University. Written
informed consents were obtained from patients at recruiting.
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