A Pharmacological Study of Alpha Adrenergic Receptor Subtypes in Smooth Muscle of Human Urinary Bladder Base and Prostatic Urethra

Kunisawa, Y; Kawabe, Kazuki; Niijima, Tadao; Honda, Kazuo; Takenaka, Oichi

doi:10.1016/s0022-5347(17)47185-0

Cited by 117 publications

(44 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Since Caine et al reported the therapeutic ef®cacy of phenoxybenzamine in BPH [6], a-adrenoceptor antagonists of three different types have been used to treat this condition. These are the ®rst-generation, nonselective a1/a2-antagonists (e.g.…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, most patients with BPH reportedly choose less aggressive interventions than TURP, although more aggressive than watchful waiting [2]. Recently, several investigations have signi®cantly more a1-adrenergic receptors in hypertrophic prostatic tissue than in normal tissue [3±5] and that blocking urethral a1-adrenoceptors causes the prostatic urethra to relax [6]. First-generation, nonselective a1/a2-antagonists, e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A comparative study of terazosin and tamsulosin for symptomatic benign prostatic hyperplasia in Japanese patients

et al. 2000

View full text Add to dashboard Cite

Objective To compare the ef®cacy and safety of an incremental-dose regimen of terazosin (1±2 mg daily) and a ®xed-dose regimen of tamsulosin (0.2 mg daily), on Japanese patients with symptomatic benign prostatic hyperplasia (BPH). Patients and methods This multicentre, single-blind, randomized trial compared terazosin and tamsulosin over 4 weeks, in 61 patients with symptomatic BPH randomly assigned to terazosin (n=31) or tamsulosin (n=30). Terazosin 0.5 mg twice daily was administered for 2 weeks, followed by 1 mg twice daily for 2 weeks. Tamsulosin (0.2 mg) was administered once daily for 4 weeks. Symptoms were evaluated using the International Prostate Symptom Score (IPSS), and quality of life (QOL) was assessed subjectively before treatment, and again after 2 and 4 weeks of treatment.Objective measurements taken before and after the treatment period were the maximum (Q max ) and average (Q ave ) urinary¯ow rates, and the percentage residual urine volume. Improvement was de®ned as a 25% decrease from baseline in IPSS, >1 point increase in QOL score, and >2.5 mL/s increase in Q max . Adverse reactions potentially related to the study drugs were recorded throughout the treatment period. Results Both terazosin and tamsulosin produced statistically signi®cant improvements in subjective and objective variables. Neither treatment affected systolic or diastolic blood pressure or pulse rate. Adverse reactions were noted in four patients (three in the terazosin group and one in the tamsulosin group). However, there was no statistically signi®cant difference in the incidence of adverse effects between the groups. Conclusions Despite the limitations of small sample size and relatively short treatment periods, terazosin and tamsulosin were equally effective in the treatment of symptomatic BPH in Japanese patients, using relatively lower doses than those used in Western countries.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A comparative study of terazosin and tamsulosin for symptomatic benign prostatic hyperplasia in Japanese patients

et al. 2000

View full text Add to dashboard Cite

show abstract

“…As alpha-1 adrenoceptors were more predominant than alpha-2 adrenoceptors in male rabbits, they were used in this study. A study involving isometric contraction of isolated muscle strips of the human proximal urethra and prostate has revealed that alpha-1 adrenoceptors participate in contraction of the lower urinary tract in humans (Kunisawa et al, 1985).…”

Section: Discussionmentioning

confidence: 99%

Effects of different alpha-1 adrenoceptor blockers on proximal urethral function using in vivo isovolumetric pressure changes

Yokota

Nagano

Osada

2005

J. Smooth Muscle Res.

View full text Add to dashboard Cite

The effects of different alpha-1 adrenoceptor blockers on the urethra and the cardiovascular system were evaluated using an in vivo isovolumetric intra-urethral pressure model in New Zealand white rabbits. The urethra of anesthetized male rabbits was cannulated through the bladder and secured at the vesico-urethral junction. The distal side of urethra under the pubic bone was also closed to allow measurement of the intra-urethral pressure. Both the intra-urethral pressure and the femoral arterial pressure were monitored. The effects of five different alpha-1 adrenoceptor blockers on the increases in both the intra-urethral pressure and blood pressure induced by phenylephrine were then examined. The inhibition rate of the alpha-1 adrenoceptor blockers prazosin, bunazosin, terazosin, alfuzosin and tamsulosin on the increase in intraurethral pressure caused as a result of contraction by phenylephrine was 87.5 ± 4.5% (mean ± S.E.), 88.0 ± 7.2%, 86.2 ± 6.2%, 81.4 ± 4.8% and 92.5 ± 5.0% respectively. The potency ranking of these alpha-1 adrenoceptor blockers was tamsulosin > bunazosin > prazosin > terazosin > alfuzosin. Their inhibition rate of the arterial pressure increase induced by phenylephrine was 81.9 ± 5.0%, 86.2 ± 5.9%, 76.0 ± 6.0%, 63.6 ± 5.7% and 58.0 ± 5.2% respectively, with a potency ranking of bunazosin > prazosin > terazosin > alfuzosin > tamsulosin. We therefore conclude that the alpha-1 adrenoceptor blockers bunazosin and prazosin have a more potent action on both the urethra and the vascular system. However, tamsulosin and alfuzosin displayed a marked blockade of the increased urethral pressure induced by phenylephrine, with much less of a blockade of arterial pressure. In the present study, tamsulosin has been shown to be the most sensitive and powerful of the alpha-1 adrenoceptor blockers on urethral smooth muscle.

show abstract

“…The preference has been for longer acting and more uroselective a 1 -adrenoceptor antagonists [Brawer et al 1993]. Prazosin [Roehrborn et al 1995], terazosin [Chapple et al 1994], doxazosin [Jardin et al 1994], and alfuzosin [Kunisawa et al 1985], a 1 -adrenoreceptor antagonists have been used to treat BPH and increase urinary outflow and lessen symptoms. However, their use is associated with adverse effects that included dizziness, severe hypotension and dry mouth.…”

Section: Introductionmentioning

confidence: 99%

Tamsulosin Versus Terazosin for Benign Prostatic Hyperplasia: A Systematic Review

Dong

Wang

Yang

et al. 2009

Systems Biology in Reproductive Medicine

View full text Add to dashboard Cite

The effectiveness and safety of tamsulosin and terazosin for patients with benign prostatic hyperplasia (BPH) was evaluated by literature review. PubMed, Embase, the Cochrane Library, Chinese biomedicine literature database (CBM), reference lists of reports, and reviews were searched for randomized controlled trials (RCTs), or quasi-RCTs of tamsulosin versus terazosin in BPH. Twelve studies involving 2,816 men were included. Outcomes included international prostate symptom score (IPSS), quality of life (QOL), maximum urinary flow rate (Q max ), average urinary flow rate (Q ave ), residual volume, prostate volume, and adverse effect (dizziness, severe hypotension, dry mouth). Relative risk was calculated for dichotomous data. Sensitivity analyses assessed the influence of baseline symptom severity. We found that tamsulosin is better than terazosin when assessed by IPSS (weighted mean difference ( (RR ¼ 0.14 95% CI [0.03, 0.77]), compared with patients receiving terazosin. Many of the high quality RCTs showed beneficial effects of tamsulosin in terms of improving IPSS. However, whether tamsulosin proves more efficacious than terazosin in long term therapy requires confirmation by additional large sample, high quality trials.

show abstract

A Pharmacological Study of Alpha Adrenergic Receptor Subtypes in Smooth Muscle of Human Urinary Bladder Base and Prostatic Urethra

Cited by 117 publications

References 10 publications

A comparative study of terazosin and tamsulosin for symptomatic benign prostatic hyperplasia in Japanese patients

A comparative study of terazosin and tamsulosin for symptomatic benign prostatic hyperplasia in Japanese patients

Effects of different alpha-1 adrenoceptor blockers on proximal urethral function using in vivo isovolumetric pressure changes

Tamsulosin Versus Terazosin for Benign Prostatic Hyperplasia: A Systematic Review

Contact Info

Product

Resources

About