Alpha-adrenergic blocking drugs in the management of benign prostatic hyperplasia: interactions with antihypertensive therapy

A prospective pilotstudy comparing the anesthetic effects of an alpha-2 agonist during holmium laser resection of the prostate and transurethral resection for prostate surgery for benign prostatic hyperplasia patients using selective alpha-1 blockers

BACKGROUND

To examine the response to an α2receptor agonist used as a sedative for patients using long-term selective α1 blockers.

METHODS

Sixty-nine consecutive patients undergoing transurethral prostate resection or holmium laser resection of the prostateunder spinal anesthesia were divided into two groups; group N (n = 37), which did not receive α1 blockers, and group T (n = 32), which was administered tamsulosin for at least 1 month before the study. Bispectral index scores, Modified Observer's Assessment of Alertness/Sedation scale scores, heart rate, and mean blood pressure were obtained under sedation using dexmedetomidine for 30 min during surgery.

RESULTS

The only significant difference found between the groups were mean bloodpressure 15 min after the first loading dose injection of dexmedetomidine. Differencesbetween both groupswere noted at 15 min(group T: 100.2 ± 12.9 mmHg; group N: 90.0 ± 17.5 mmHg; P = 0.08), 20 min (group T: 99.8 ± 12.3 mmHg; group N: 87.4 ± 15.0 mmHg; P < 0.00), 25 min (group T: 99.3 ± 13.4 mmHg; group N: 85.4 ± 13.8 mmHg; P < 0.00), and 30 min (group T: 98.8 ± 13.1 mmHg; group N: 84.5 ± 13.5 mmHg; P < 0.00).

CONCLUSIONS

The use of α2 agonists is appropriate during surgery for benign prostatic hyperplasia patients using tamsulosin, and there is no need to alter the dose. Alertness with anesthesia involving α2 agents was maintained for patients using long-term tamsulosin and patients who did not use tamsulosin.

TRIAL REGISTRATION

The study was retrospectively registered with the Clinical Research Informational Service ( KCT0002967 , July 2, 2018).

Efficacy and Safety of a Fixed-Dose Combination Therapy of Tamsulosin and Tadalafil for Patients With Lower Urinary Tract Symptoms and Erectile Dysfunction: Results of a Randomized, Double-Blinded, Active-Controlled Trial

BACKGROUND

Phosphodiesterase type 5 inhibitors and α-adrenergic blocking agents (α-blockers) are widely used for the treatment of erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH).

AIMS

To assess the efficacy and safety of fixed-dose combinations (FDCs) of tamsulosin and tadalafil compared with tadalafil monotherapy in patients with comorbid BPH-associated LUTS and ED.

METHODS

A randomized, double-blinded, active-controlled trial was conducted of 510 men with BPH-associated LUTS and ED. Patients were treated with FDCs of tamsulosin 0.4 mg plus tadalafil 5 mg (FDC 0.4/5 mg), tamsulosin 0.2 mg plus tadalafil 5 mg (FDC 0.2/5 mg), or tadalafil 5 mg for a 12-week treatment period. For a subsequent 12-week extension period, the patients were administered FDC 0.4/5 mg.

OUTCOMES

The primary outcomes were changes from baseline in total International Prostate Symptom Score (IPSS) and International Index of Erectile Function erectile function domain (IIEF-EF) score at week 12 to prove superiority and non-inferiority of FDCs compared with tadalafil 5 mg. The safety assessments were adverse reactions, laboratory test results, and vital signs at week 24.

RESULTS

The mean changes in total IPSS and IIEF-EF scores were -9.46 and 9.17 for FDC 0.4/5 mg and -8.14 and 9.49 for tadalafil 5 mg, respectively, which indicated superiority in LUTS improvement (P = .0320) and non-inferiority in ED treatment with FDC 0.4/5 mg compared with tadalafil 5 mg. However, the results from FDC 0.2/5 mg failed to demonstrate superiority in LUTS improvement. No clinically significant adverse events regarding the investigational products were observed during the 24-week period.

CLINICAL IMPLICATIONS

The FDC 0.4/5 mg is the first combined formulation of an α-blocker and a phosphodiesterase type 5 inhibitor that offers benefits in patient compliance and as add-on therapy in patients with comorbid BPH-associated LUTS and ED.

STRENGTHS AND LIMITATIONS

The study clearly demonstrated the advantage of FDC 0.4/5 mg. The main advantage of FDC 0.4/5 mg was the enhanced efficacy on BPH-associated LUTS comorbidity with ED, the lower incidence of side effects, and the simplification and convenience of therapy, which led to better overall patient compliance. However, the lack of a tamsulosin monotherapy control group was a limitation of this study.

CONCLUSION

The FDC 0.4/5 mg therapy was safe, well tolerated, and efficacious, indicating that combination therapy could provide clinical benefits for patients with BPH-associated LUTS complaints and ameliorate the comorbidity of ED. Kim SW, Park NC, Lee SW, et al. Efficacy and Safety of a Fixed-Dose Combination Therapy of Tamsulosin and Tadalafil for Patients With Lower Urinary Tract Symptoms and Erectile Dysfunction: Results of a Randomized, Double-Blinded, Active-Controlled Trial. J Sex Med 2017;14:1018-1027.

The Vasodilatory Effect of Alfuzosin and Tamsulosin in Passive Orthostasis: A Randomised, Double-Blind, Placebo-Controlled Study

OBJECTIVE

To compare in details the effects of urologically used alpha(1)-blockers alfuzosin and tamsulosin on the cardiovascular responses to passive orthostasis.

METHODS

The responses to passive orthostasis (tilt provocation at 60 degrees for 8 min) were measured in normotensive healthy volunteers with finger blood pressure method and whole-body impedance cardiography prior to the administration of the drugs as well as three days after the beginning of the randomised, double-blind medications. The parallel treatments were standard clinically used doses of alpha(1)-blockers alfuzosin (5 mg twice daily, n=10), tamsulosin (0.4 mg once daily, n=10), or placebo (n=11).

RESULTS

When measured prior to the head-up tilt test in supine position, neither alfuzosin nor tamsulosin significantly changed any of the cardiovascular variables. During the passive orthostasis, however, both tamsulosin and alfuzosin reduced systemic vascular resistance index compared to pre-drug responses (-540 and -462 dyns/cm(5)m(2), respectively, p<0.05). Both drugs also augmented orthostatic responses of heart rate (11 and 9 bpm, respectively, p<0.05) and cardiac index (0.50 and 0.40 l/min/m(2), respectively, p<0.05) but not those of stroke index when compared to the responses during placebo or before the administration of the drugs. The alfuzosin and tamsulosin groups did not significantly differ from each other in terms of any parameter.

CONCLUSIONS

Both alfuzosin and tamsulosin have clear cardiovascular effects, which are most strikingly evident in the influences on systemic vascular resistance and cardiac output.

Common conditions of the aging male: erectile dysfunction, benign prostatic hyperplasia, cardiovascular disease and depression

With increasing life expectancy, medical profession will be faced with the task of ensuring that the large, aging population remains healthy and vital despite the face of increasing healthcare costs. Naturally, urology as a specialty is concerned with important geriatric issues. This article will focus specifically on the aging male population and the health problems that most frequently plague them. Four major, non-cancer, disease states have been identified that adversely effect males over the age of 50. These conditions are: erectile dysfunction (ED), benign prostatic hyperplasia (BPH), cardiovascular disease (CVD) and depression. A literature search of PubMed was conducted using the key words ED, BPH, CVD and depression as well as ADAM (Androgen Decline in the Aging Male) and quality of life (QoL). NIH and WHO conference proceedings and publications were also referenced to insure detail and accuracy of data. Information was then organized and correlated in order to provide a detailed description of the key conditions and their interrelatedness. The spectrum of research performed thus far regarding this topic has done little to investigate the effects, causes and correlations between these conditions. Research has been done linking two or three of these conditions; however, there remains to be information discussing the four disease states in terms of their possible cause and effect relationships or the effectiveness of parallel, multi-disciplinary approach to their therapy. This report calls attention to the benefits of viewing and researching the above mentioned conditions as possibly interrelated, as opposed to the traditional view of them as separate, unrelated and independently treatable disease states. ED, BPH, CVD and depression are all common conditions that accompany aging and negatively impact QoL. They almost always develop with age and precipitate considerable morbidity and may even result in mortality. Furthermore, the presentation of one condition may correlate with the development of another. The inter-relation of these conditions, as evident from their underlying similarities, cause-and-effects relationships and therapeutic consequences, should be enough to warrant a multidisciplinary approach to their research. This approach, combined with careful choice of therapy, parallel and singular, will help providers reach their goal to keep patients healthy, and more importantly happy, late into their life, thus realizing the concept of "successful aging".

Effect of doxazosin on rat urinary bladder function after partial outlet obstruction

Hypoxia induced by partial outlet obstruction is believed to play a major role in both the hypertrophic and degenerative effects of partial outlet obstruction. Doxazosin (dox) is a clinically effective alpha-adrenergic antagonist used in the treatment of symptomatic benign prostatic hyperplasia (BPH). Although the major therapeutic effect of the agent is believed to occur on the smooth muscle components of the prostate by reducing prostatic urethral resistance and thus improving emptying, dox may have part of its clinical action via effects mediated by other actions, including via spinal alpha-adrenergic receptors or direct effects on the bladder, possibly via inhibition of vascular alpha receptors. The specific aim of the current study was to determine whether dox pretreatment on rats affects blood flow to the bladder and reduces the level of bladder dysfunction induced by partial outlet obstruction. In part 1, eight rats were separated into two groups of four rats each. Group 1 received oral administration of dox (30 mg/kg) for 4 weeks; group 2 received vehicle (5% dimethyl sulfoxide). After 4 weeks of treatment, blood flow studies were performed using fluorescent microspheres and the bladders excised, frozen, and submitted to Interactive Medical Technologies (IMT) for blood flow analysis. In part 2, 32 adult male rats were separated into four groups of eight rats each. Groups 1 and 2 received oral administration of dox (30 mg/kg) for 4 weeks, groups 3 and 4 received vehicle (5% dimethyl sulfoxide). At 4 weeks, the rats in groups 1 and 3 received partial outlet obstructions and treatment continued for an additional 2 weeks. After 6 weeks of treatment (total), each rat was anesthetized, the bladder excised, weighed, and isolated strips mounted and contractility studies performed. 1) Four weeks pretreatment of rats with dox increased blood flow to the bladder in both the control and obstructed groups. 2) Partial outlet obstruction induced a mild decrease in blood flow. 3) The magnitude of the increased bladder weight in the vehicle-treated obstructed group was significantly greater than in the dox-treated obstructed group. 4) Partial outlet obstruction resulted in significant decreases in the contractile response to field stimulation in both treated and non-treated rats. The magnitude of the decreased response was significantly greater in the non-treated rats. 5) The response to potassium chloride was significantly reduced by partial outlet obstruction in the vehicle-treated group but not in the dox-treated group. 6) The time to maximal tension was significantly increased in response to carbachol, adenosine triphosphate, and potassium chloride. However, the magnitude of the increase was significantly greater for the vehicle-treated obstructed groups stimulated by potassium chloride than for the dox-treated groups. Dox treatment of rats increased blood flow to the bladder and reduced the severity of the response to partial outlet obstruction. These beneficial effects would be due to pharmacological effects on alpha-adrenergic systems outside those present in the prostate. These include effects on blood flow to the bladder, effects on the micturition centers of the central nervous system, spinal reflexes, and alpha-adrenergic receptors in the urethra and bladder.

Tamsulosin for the treatment of benign prostatic hypertrophy

OBJECTIVE

To review the information necessary to assess the efficacy and safety of tamsulosin compared with other adrenergic antagonists for treatment of symptomatic benign prostatic hyperplasia.

DATA SOURCES

A search was conducted of Cumulated Index Medicus, January 1993-August 1999, which was restricted to human trials and English-language journals.

STUDY SELECTION AND DATA EXTRACTION

Efficacy studies were included if the design was randomized and included a control group. Drug safety was assessed using data from any patient series or controlled study.

DATA SYNTHESIS

Tamsulosin, a uroselective alpha1A-adrenergic receptor antagonist, relaxes smooth muscle in the prostate and bladder neck, thereby enhancing bladder emptying. In randomized, controlled clinical trials using standardized instruments, tamsulosin improves obstructive voiding symptoms by at least 25% in 65-80% of patients with symptomatic benign prostatic hyperplasia. Tamsulosin also improves peak urinary flow rate by 1.4-3.6 mL/sec in various studies and reduces post-void residual urine volume. The usual dosage of tamsulosin was 0.4 or 0.8 mg orally once a day in the studies performed in the US and Europe; daily doses of 0.1-0.4 mg were used in studies performed in Japan. The beneficial effects of tamsulosin on voiding symptoms, peak urinary flow rate, and bladder emptying appear to be dose-related, up to a ceiling dose of 0.4 mg. The most common adverse effects are headache, asthenia, dizziness, and rhinitis-like complaints. Retrograde or delayed ejaculation occurs in 4.5-14.0% of patients and has required discontinuation of treatment in a minority of these patients. At the usual dose of 0.4-0.8 mg/d, tamsulosin does not appear to significantly reduce blood pressure, increase heart rate, or cause first-dose syncope; therefore, dosage titration is not necessary when initiating treatment. Use of nifedipine, enalapril, atenolol, furosemide, or digoxin does not require dosage modification when tamsulosin is initiated concomitantly; hypotension has not been reported with combined use of tamsulosin and these commonly used agents.

CONCLUSIONS

Tamsulosin is an improvement over other alpha-adrenergic antagonists for the management of symptoms of benign prostatic hyperplasia. It is a more convenient alternative that does not require initial dosage titration, has a fast onset of action, and has a low potential to cause hypotension when used alone or in combination with commonly used antihypertensive agents. It is more costly than some of the other second-generation alpha-adrenergic antagonists.