The Effect of Switching Patients with Symptomatic Benign Prostatic Hyperplasia from Tamsulosin 0.2 mg to 0.4 mg ()
Abstract
Objectives: In 2010,
tamsulosin 0.2 mg (OD) was withdrawn from Thailand and replaced with tamsulosin
0.4 mg (OD). Therefore, we assessed the impact of this change on the patients,
at a men’s health clinic, with lower urinary tract symptoms suggestive of
benign prostatic hyperplasia (LUTS/BPH). Material and Methods: Subjects
were 100 men with BPH who had been taking tamsulosin 0.2 mg as needed for at
least 3 months. The outcome measures were IPSS, AMS and IEFF5 scores and
uroflowmetry. Tolerability was evaluated on by adverse events. Changes from
baseline were assessed using the paired t-test. SPSS version 12.0 was
used for statistical analysis, with p
< 0.05 considered significant. Results: The mean follow up of
tamsulosin 0.2 and 0.4 mg were 20.23 and 10.56 months respectively. On
switching from tamsulosin 0.2 to 0.4 mg, mean IPSS score improved from 15.54 ± SD 1.25
to 14.13 ± SD 1.09 (p = 0.034), Q max 15.91 cm3/sec ± SD 1.36 to 16.69 cm3/sec ± SD 1.52
(p = 0.128), and nocturia 3.15 ± SD 0.32 to 2.68 ± SD 0.39 (p = 0.015),
respectively. However IEFF-5 score and AMS score increased from14.78 ± SD 1.38
to 15.79 ± SD 1.03 (p = 0.0055) and 34.76 ± SD 2.76
to 33.21 ± SD 2.62 (p = 0.0853), respectively. Treatment-related
adverse events of Tamsulosin 0.2 mg included dizziness (4%), postural
hypotension (3%) and retrograde ejaculation (3%). Interestingly,
no withdrawals resulted from adverse events during Tamsulosin 0.4 mg
assessment. Conclusions: Switching to tamsulosin 0.4 mg improves LUTS.
The change was well tolerated by the majority of patients. Increased symptoms
scores of erectile dysfunction and aging male during the study may be due to
increased age.
1. Introduction
Symptomatic benign prostatic hyperplasia (BPH) may affect up to 30% of men in their early 70s, causing urinary symptoms of bladder outlet obstruction [1]. Community and practice based studies suggest that men with lower urinary tract symptoms (LUTS) can expect slow progression of symptoms [2,3].
Medical therapies to treat LUTS/BPH include α1- adrenergic receptor antagonists (terazosin, doxazosin, tamsulosin, and alfuzosin), 5α-reductase inhibitors such as finasteride and dutasteride, and phytotherapy. Physicians choosing treatment to achieve symptom relief must take into account factors such as the clinical benefits, potential for morbidity, probable long-term efficacy, and costs [4]. Tamsulosin is a more selective α1A subtype antagonist, which maintains the α-antagonist effect on the prostatic capsule and bladder neck but has less of an effect on the vascular system and blood pressure. Tamsulosin has a favorable side effect profile in regard to problems related to hypotension and dizziness compared to those of terazosin and doxazosin [5].
In Thailand, tamsulosin 0.2 mg was the first line treatment in patients with BPH or LUTS but it was withdrawn and switched to tamsulosin 0.4 mg in 2010. Our study was designed to confirm previous research, which compared the efficacy of tamsulosin 0.4 mg and 0.2 mg in different groups, while our study was done in the same patients.
Our study observed patients who had BPH and LUTS symptoms and were first treated with tamsulosin 0.2 mg then, later, with tamsulosin 0.4 mg. The patients were evaluated for IPSS, side effects and uroflowmetry.
2. Materials and Methods
After obtaining the local ethics committee’s approval, we reviewed data between January 2007 and December 2010 from out patient cards for a retrospective study. A total of 130 patients were recruited in our study. Patients were diagnosed with LUTS due to BPH and aged above 50 years old at the first diagnosis and treated with tamsulosin (0.2 mg) in the outpatient department of a university hospital.
Thirty patients were excluded from our study due to having been treated with combined therapy, having other urological diseases (example: bladder cancer, prostate cancer, urinary tract infection (UTI)) or wanting to change to other drugs. A hundred patients remained in our study. The patients were treated with tamsulosin 0.2 mg in their first drug treatment and then switched to tamsulosin 0.4 mg in 2010 due to the withdrawal of tamsulosin 0.2 and its replacement with tamsulosin 0.4 mg. Age, time of follow up, IPSS scores, nocturia, erectile dysfunction using International Index Erectile Function (IIEF-5) scores, Uroflowmetry (maximum flow rate and post void residual urine), complications from tamsulosin were collected from records in outpatient cards. Patients were followed up every 3 months for IPSS scores, rectal examination and side effects, and uroflowmetry every 12 months. The mean follow up time for tamsulosin 0.2 mg was 20.23 ± 2.44 months and after switching to tamsulosin 0.4 mg the mean was 10.56 ± 1.09 months. For statistical analysis, we used the paired t-test and Stata version 12.0 with p-value < 0.05 for statistical significance.
3. Results
In result of our study, table 1 details the median ± standard deviation (SD) of each data. The average age was 68.13 ± 2.26 years when starting treatment with tamsulosin 0.2 mg and 70.46 ± 1.55 years after switching to tamsulosin 0.4 mg. Mean IPSS score before treatment was 20.23 ± 2.46, after treatment with tamsulosin 0.2 mg it was 15.54 ± 1.25 and after switching to tamsulosin 0.4 mg it was 14.13 ± 1.09. Regarding maximum flow rate and post residual urine: the maximum flow for tamsulosin 0.2 mg was 15.91 ± 1.36 cm3/sec and for tamsulosin 0.4 mg it was 16.69 ± 1.52 cm3/sec, average of post void residual urine for tamsulosin 0.2 mg was 73.57 ± 7.16 cm3 and for tamsulosin 0.4 mg it was 63.89 ± 5.54 cm3. The outcome of the International Index of Erectile Function questionnaire (IIEF-5) after treatment with tamsulosin 0.2 mg was 15.79 ± 6.60 and for tamsulosin 0.4 mg it was 14.78 ± 1.03. The average of frequency of nocturia after treatment with tamsulosin 0.2 mg was 3.15 ± 0.32/night and for tamsulosin 0.4 mg it was 2.68 ± 0.39/night. In aging male symptoms, we used the Aging Male Score (AMS) for evaluation, but in our analysis was limited to 60 patients due to some patients failed to complete AMS forms. The average score for AMS with tamsulosin 0.2 mg was 33.21 ± 2.76 and after switching to tamsulosin 0.4 mg it became 34.76 ± 2.62.
Table 2 Data analysis with statistical methods. IPSS scores data show a statistically significant increase after switching from tamsulosin 0.2 mg to treatment with tamsulosin 0.4 mg (p-value = 0.0034). In uroflowmetry, maximum flow rate in patients after treatment with tamsulosin 0.4 mg was better than with tamsulosin 0.2 mg but not statistically significant (p-value = 0.128). Post void residual urine after switching to tamsulosin 0.4 mg was less than that after treatment with tamsulosin 0.2 mg but, again, the difference was not statistically significant (p-value = 0.073). In erectile dysfunction it was shown that, after switching to treatment with tamsulosin 0.4 mg, IIEF-5 scores were less than when treated with tamsulosin 0.2 mg at a statistically significant level (p-value = 0.005). The higher dosage of tamsulosin also brought about a statistically significant decrease in the frequency of nocturia (p-value = 0.015). The aging male score after