The alpha-adrenergic antagonist prazosin promotes cytosolic siRNA delivery from lysosomal compartments

The widespread use of small interfering RNA (siRNA) is limited by the multiple extra- and intracellular barriers upon in vivo administration. Hence, suitable delivery systems, based on siRNA encapsulation in nanoparticles or its conjugation to targeting ligands, have been developed. Nevertheless, at the intracellular level, these state-of-the-art delivery systems still suffer from a low endosomal escape efficiency. Consequently, the bulk of the endocytosed siRNA drug rapidly accumulates in the lysosomal compartment. We recently reported that a wide variety of cationic amphiphilic drugs (CADs) can promote small nucleic acid delivery from the endolysosomal compartment into the cytosol via transient induction of lysosomal membrane permeabilization. Here, we describe the identification of alternate siRNA delivery enhancers from the NIH Clinical Compound Collection that do not have the typical physicochemical properties of CADs. Additionally, we demonstrate improved endolysosomal escape of siRNA via a cholesterol conjugate and polymeric carriers with the α1-adrenergic antagonist prazosin, which was identified as the best performing delivery enhancer from the compound screen. A more detailed assessment of the mode-of-action of prazosin suggests that a different cellular phenotype compared to typical CAD adjuvants drives cytosolic siRNA delivery. As it has been described in the literature that prazosin also induces cancer cell apoptosis and promotes antigen cross-presentation in dendritic cells, the proof-of-concept data in this work provides opportunities for the repurposing of prazosin in an anti-cancer combination strategy with siRNA.

Risk of Severe COVID-19 in Prevalent Users of Alpha-1 Adrenergic Receptor Antagonists: A National Case-Control Study of Medicare Beneficiaries

BACKGROUND

Alpha-1 adrenergic receptor antagonists prevent cytokine storm in mouse sepsis models. This led to the hypothesis that alpha-1 blockers may prevent severe coronavirus disease 2019 (COVID-19), which is characterized by hypercytokinemia and progressive respiratory failure.

METHODS

We performed an observational case-control study in male Medicare beneficiaries aged 65 years or older, with or without benign prostatic hyperplasia (BPH), and treated with alpha-1 receptor blockers or 5-alpha reductase inhibitors. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were estimated for outcomes of uncomplicated and severe COVID-19 hospitalization (intensive care unit admission, invasive mechanical ventilation, or death).

RESULTS

There were 20,963 cases of hospitalized COVID-19 matched to 101,161 controls on calendar date and neighborhood of residence. In the primary analysis (males with BPH), there was no difference in risk of uncomplicated COVID-19 hospitalization (aOR 1.08, 95% CI 0.996-1.17) or hospitalization with severe complications (aOR 0.97, 95% CI 0.88-1.08). In the secondary analysis (males with or without BPH), the corresponding aORs were 1.02 (95% CI, 0.96-1.09) (uncomplicated) and 0.99 (95% CI, 0.91-1.07) (complicated), respectively. Subgroup and sensitivity analyses yielded similar results. Of note, there was no difference in risk of severe COVID-19 hospitalization when comparing non-selective vs selective alpha-1 blocker use (aOR 0.98, 95% CI 0.86-1.10), higher- vs lower-dose alpha-1 blocker use (aOR 0.96, 95% CI 0.86-1.08), or current vs remote alpha-1 blocker use (aOR 1.04, 95% CI 0.91-1.18).

CONCLUSIONS

Prevalent use of alpha-1 receptor blockers was not associated with a protective or harmful effect on risk of uncomplicated or severe hospitalized COVID-19.

Benign Prostatic Hyperplasia: Rapid Evidence Review

Lower urinary tract symptoms from benign prostatic hyperplasia affect 25% of U.S. men, nearly one-half of whom have at least moderate symptoms. Sedentary lifestyle, hypertension, and diabetes mellitus increase risk of symptoms. Evaluation is focused on determining severity of symptoms and therapy to improve symptoms. Rectal examination has limited accuracy in evaluating prostate size. Transrectal ultrasonography is preferred to verify size when starting 5-alpha reductase therapy or considering surgery. Serum prostate-specific antigen testing is not recommended in routine evaluation of lower urinary tract symptoms, and shared decision-making should be used for cancer screening decisions. The International Prostate Symptom Score is the best way to track symptoms. Self-management methods, including limiting evening fluid intake, reducing caffeine and alcohol intake, toilet and bladder training, pelvic floor exercises, and mindfulness techniques, can improve symptoms. Although saw palmetto is not effective, the herbal treatments Pygeum africanum and beta-sitosterol may be effective. Primary medical treatment involves alpha blockers or phosphodiesterase-5 inhibitors. Alpha blockers offer rapid benefit and can be used for acute urinary retention. Combining alpha blockers and phosphodiesterase-5 inhibitors is not beneficial. For uncontrolled symptoms, 5-alpha reductase inhibitors should be started if the prostate volume is 30 mL or greater by ultrasonography. 5-Alpha reductase inhibitors take up to one year to be fully beneficial and are more effective when taken with alpha blockers. Only 1% of patients with lower urinary tract symptoms require surgery. Although transurethral resection of the prostate improves symptoms, many less invasive options with varying effectiveness can be considered.

Effects of adrenergic α-antagonists on the early life stages of Japanese medaka (Oryzias latipes)

The occurrence of pharmaceuticals in the aquatic environment has stimulated considerable research efforts into their potential ecotoxicological consequences. There are a number of pharmaceuticals targeting adrenergic receptors; however, relatively few studies have explored the effects of adrenergic α-antagonists (or α-blockers) on fish. In this study, moxisylyte was selected as a representative α-blocker, and Japanese medaka embryos were exposed to moxisylyte (1-625 μg/L) for 44 days. Moxisylyte caused no significant or only marginal effects on the mortality, development, and growth; however, most genes involved in detoxification and antioxidant were transcriptionally upregulated, and antioxidant enzymes activities were induced as well. Moxisylyte exposure resulted in transcriptional downregulation of most of the steroidogenesis genes, and accordingly, the mRNA levels of steroid hormone receptors and vitellogenin decreased, particularly in males, indicating that moxisylyte disrupts the hypothalamic-pituitary-gonadal (HPG) axis in a gender-specific manner. Therefore, the risk of α-blockers on fish should not be overlooked and deserves further investigation.

Is tadalafil associated with decreased risk of major adverse cardiac events or venous thromboembolism in men with lower urinary tract symptoms?

Purpose

To evaluate the association of tadalafil, a phosphodiesterase-5 inhibitor (PDE5I), with major adverse cardiac events (MACE) or venous thromboembolism (VTE) in men with lower urinary tract symptoms (LUTS).

Methods

Data was obtained from the TriNetX Research Network, ICD-10 codes were used to identify men with LUTS, MACE, and VTE. In addition, demographic characteristics and use of tadalafil or alpha-blocker was evaluated. Then, unbalanced and balanced association analyses was performed to assess the relation between tadalafil and/or alpha-blocker use with MACE/VTE.

Results

After participant selection, analysis included 821,592 men that did not use an alpha blocker or tadalafil, 5,004 men that used tadalafil but no alpha blocker, 327,482 men that used an alpha blocker but no tadalafil, and 6,603 men that used both an alpha blocker and tadalafil. On balanced analysis, tadalafil was independently associated with a decreased risk of MACE/VTE within a 3-year time period (OR = 0.59, 95%CI 0.49–0.70, p < 0.0001). Among men with a history of alpha blocker use, tadalafil use was also independently associated with a decreased risk of MACE or VTE, both before and after controlling for potentially confounding variables (OR = 0.57, 95%CI: 0.50–0.66; p < 0.0001).

Conclusions

In our study, tadalafil was associated with a decreased risk of MACE/VTE in men with LUTS with and without a history of alpha blocker use. It is time to perform further long-term prospective randomized studies to further analyze the cardiovascular effects of PDE5Is as combination treatment with alpha blockers in the management of LUTS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04005-3.

Impact of coronavirus disease on the management of lower urinary tract symptoms and voiding dysfunction

PURPOSE OF REVIEW

Coronavirus disease (COVID-19) has caused a crisis in the entire healthcare system since its emergence. The urgency and priority of various diseases have impacted the medical and surgical treatment in this period. We aim to review the impact of COVID-19 on lower urinary tract symptoms (LUTS) and management.

RECENT FINDINGS

There may be a relationship between COVID-19 and de novo or increased LUTS. Patients with LUTS should also be evaluated for COVID-19. Management of diseases has varied during the COVID-19 due to the density of the pandemic. Virtual consultations can mitigate patients who are postponed or cancelled, such as patients with LUTS. Patients suffering voiding dysfunction may manage with oral medications such as alpha blocker and 5-alpha reductase inhibitor via telemedicine. Minimally invasive procedures with a low risk of complications and a short hospitalization time should be considered in complicated cases such as the inability to catheterize.

SUMMARY

Telemedicine should be implemented on managements of noncomplicated LUTS and voiding dysfunction. Each centre can schedule its LUTS management approach according to the density of pandemic. Virtual consultations need to be developed to compete with face-to-face consultations.

[How to manage acute urine retention?]

Acute urinary retention is a common problem, mainly among elderly men. The first step in the treatment is the placement of an indwelling urinary catheter. It's common practice to remove the catheter after a short period of time to observe if spontaneous micturition returns. However, there is no consensus on how to do this. This article summarizes recommendations regarding catheter removal based on available literature and expert opinion. The most important recommendation is treatment with an α-blocker before catheter removal, since this significantly increases the chances of spontaneous micturition (RR 1.39 [1.18-1.64]). Catheter removal should take place within 3 to 5 days after placement after elimination of provoking factors, such as immobilization, infection and obstipation. Referral to a urologist is recommended if spontaneous micturition does not return after multiple attempts of catheter removal, in case of recurrent urinary retention and acute urinary retention in young men and females.

[Medical expulsive treatment for ureteral stones.]

INTRODUCTION

Medical Expulsive Treatment (MET) for ureteral stones has been questioned for the last few years.

OBJECTIVES

The main goal of our study is to define the indications of MET, the different drugs that are used and their effectiveness and to propose a follow-up strategy. Secondary objectives include the effectiveness of MET in some special subgroups such as pregnant women and children and to assess aspects of MET cost-effectiveness compared with other options for ureteral lithiasis treatment (ureterorenoscopy or extracorporeal shock wave lithotripsy).

MATERIAL AND METHODS

We have reviewed the most relevant clinical trials and meta-analysis evaluating the impact of the different drugs available for MET. For the research we used some keywords like "medical expulsive treatment/therapy", "ureteral lithiasis", "urolithiasis", "effectiveness", "alpha-blockers" and "calcium-antagonists". MEDLINE database was used for there search (using the portal web Pubmed).

RESULTS

Highest quality studies currently availables how significant methodological limitations leading to heterogeneous and restricted evidence, which is only applicable to patients and lithiasis with specific conditions. Nevertheless, in general terms, it seems that MET can play a certain role in the expulsion of lithiasis ≥ 5mm y ≤ 10 mm located in the distal ureter, although it has not been possible to demonstrate that any of the drugs used may have special superiority in terms of effectiveness. In pregnancy and children, the recommendations of MET are also irregular. Finally, MET seemsto be an alternative cost-effective compared to active options of treatment.

CONCLUSIONS

Higher quality clinical trials are needed to reliably advice MET. With the current evidence, it appears that MET can improve the expulsion of distal ureteral lithiasis ≥ 5 mm and ≤ 10 mm, even though we have not found differences between the drugs that are available for MET.

[The use of alfuzosin in the treatment of patients with acute urinary retention]

AIM

To study the efficiency of using alfuzosin 10 mg (Alfuprost MR, SUN Pharma) in routine clinical practice in order to predict its feasibility for treating acute urinary retention.

MATERIALS AND METHODS

A total of 47 patients, aged from 54 to 88 years old (mean 68.5+/-5.6) with acute urinary retention due to benign prostatic hyperplasia were treated at the urology department of City clinical hospital named after D.D. Pletnev from September to December 2019. 14 patients were excluded from the study since they had chronic urinary retention. In all cases, urethral catheter was put and left in place for 24-72 hours (mean 44+/-12). All 33 patients were prescribed alfuzosin 10 mg. After removal of the urethral catheter, spontaneous voiding was restored in 19 patients. Transurethral resection of the prostate was consequently performed in three patients. In one patient, the urethral catheter was changed to cystostomy tube due to the urethritis. Recurrent urinary retention occurred in 10 men, and 8 patients underwent cystostomy. In other two cases, spontaneous voiding was restored after repeated removal of the urethral catheter.

RESULTS

the efficiency of conservative therapy was 63.6% (21/33). According to our results, history of severe lower urinary tract symptoms, the prostate volume more than 50 cc and intravesical protrusion of more than 1 cm have a significant influence on the outcome of conservative therapy in patients with acute urinary retention.

CONCLUSIONS

Based on a prospective study, a high efficiency and safety of the Alfuprost MP 10 mg/day in patients with acute urinary retention was established.

Mending the fluorescence of two α-blockers through a semiquinoid formation: Hyphenated with experimental design optimization

Herein, a selective and rapid spectrofluorimetric method coupled with experimental design approach for reliable and efficient determination of two α-blockers, namely: terazosin hydrochloride (TER) and doxazosin mesylate (DOX) in their marketed tablets was developed. The presented method adopts formation of a semi-quinoid form of the studied drugs in borate buffer. The effects of parameters influencing fluorescence intensity including pH, the volume of buffer and diluting solvent were optimized using an experimental design methodology. The optimum conditions were found to be pH: 9.8, the volume of buffer: 2.0 mL and diluting solvent: water. Under the optimum experimental conditions, a large enhancement of the studied drugs fluorescence was obtained, measured at 387 after excitation at 246 nm for either TER or DOX with limits of detection 0.05 and 0.14 ng mL^-1 and limits of quantification 0.14 and 0.43 ng mL^-1 in the concentration ranges of 0.2-30.0 ng mL^-1 and 0.5-30.0 ng mL^-1 for TER and DOX, respectively. The presented method was validated according to the ICH guidelines. Furthermore, it extended to perform the content uniformity testing and analysis of the studied drugs in spiked human plasma with % recovery (96.00 ± 0.45-101.42 ± 1.20%, n = 3).

Effects of imidazoline and nonimidazoline α-adrenoceptor agonists and antagonists, including xylazine, medetomidine, dexmedetomidine, yohimbine, and atipamezole, on aggregation of feline platelets

OBJECTIVE

To examine the effects of imidazoline and nonimidazoline α-adrenergic agents on aggregation of feline platelets.

SAMPLE

Blood samples from 12 healthy adult cats.

PROCEDURES

In 7 experiments, the effects of 23 imidazoline and nonimidazoline α-adrenoceptor agonists or antagonists on aggregation and antiaggregation of feline platelets were determined via a turbidimetric method. Collagen and ADP were used to initiate aggregation.

RESULTS

Platelet aggregation was not induced by α-adrenoceptor agonists alone. Adrenaline and noradrenaline induced a dose-dependent potentiation of ADP- or collagen-induced aggregation. Oxymetazoline and xylometazoline also induced a small potentiation of ADP-stimulated aggregation, but other α-adrenoceptor agonists did not induce potentiation. The α₂-adrenoceptor antagonists and certain imidazoline α-adrenergic agents including phentolamine, yohimbine, atipamezole, clonidine, medetomidine, and dexmedetomidine inhibited adrenaline-potentiated aggregation induced by ADP or collagen in a dose-dependent manner. The imidazoline compound antazoline inhibited adrenaline-potentiated aggregation in a dose-dependent manner. Conversely, α₁-adrenoceptor antagonists and nonimidazoline α-adrenergic agents including xylazine and prazosin were ineffective or less effective for inhibiting adrenaline-potentiated aggregation. Moxonidine also was ineffective for inhibiting adrenaline-potentiated aggregation induced by collagen. Medetomidine and xylazine did not reverse the inhibitory effect of atipamezole and yohimbine on adrenaline-potentiated aggregation.

CONCLUSIONS AND CLINICAL RELEVANCE

Adrenaline-potentiated aggregation of feline platelets may be mediated by α₂-adrenoceptors, whereas imidazoline agents may inhibit in vitro platelet aggregation via imidazoline receptors. Imidazoline α-adrenergic agents may have clinical use for conditions in which there is platelet reactivity to adrenaline. Xylazine, medetomidine, and dexmedetomidine may be used clinically in cats with minimal concerns for adverse effects on platelet function.

Safety profile of phentolamine mesylate as reversal agent of pulpal and soft tissue dental anesthesia: a systematic review and meta-analysis

OBJECTIVE

To systematically review the safety of phentolamine mesylate as a reversal agent for pulpal and soft tissue dental anesthesia.

DATA SOURCES

Comprehensive search, up to August 2018, was performed in three major electronic databases. The methodologic quality of all the included studies was assessed using Cochrane Collaboration for randomized clinical trials.

RESULTS

A total of nine studies were included for qualitative and quantitative assessment. The number of events was 269 in 2,057 participants in the phentolamine mesylate group, and 179 in 1,338 participants of the control group (odds ratio 1.19; 95% confidence interval 1.03 to 1.39). In the data segregated based on age, four studies conducted on children and adolescents revealed an odds ratio of 0.68, whereas two studies on adults revealed an odds ratio of 1.58.

CONCLUSION

There were no severe complications reported in any of the included studies, but the occurrence of adverse events (mild and moderate) was greater in the phentolamine mesylate group compared to the control group. Age has a significant effect on the possibility of adverse events with phentolamine mesylate.

Is Tamsulosin 0.2 mg Effective and Safe as a First-Line Treatment Compared with Other Alpha Blockers?: A Meta-Analysis and a Moderator Focused Study

PURPOSE

Tamsulosin 0.2 mg is used widely in Asian people, but the low dose has been studied less than tamsulosin 0.4 mg or other alpha blockers of standard dose. This study investigated the efficacy and safety of tamsulosin 0.2 mg by a meta-analysis and meta-regression.

MATERIALS AND METHODS

We conducted a meta-analysis of efficacy of tamsulosin 0.2 mg using International Prostate Symptom Score (IPSS), maximal urinary flow rate (Qmax), post-voided residual volume (PVR), and quality of life (QoL). Safety was analyzed using adverse events. Relevant studies were searched using MEDLINE, EMBASE, and Cochrane library from January 1980 to June 2013.

RESULTS

Ten studies were included with a total sample size of 1418 subjects [722 tamsulosin 0.2 mg group and 696 other alpha-blockers (terazosin, doxazosin, naftopidil, silodosin) group]. Study duration ranged from 4 to 24 weeks. The pooled overall standardized mean differences (SMD) in the mean change of IPSS from baseline for the tamsulosin group versus the control group was 0.02 [95% confidence interval (CI); -0.20, 0.25]. The pooled overall SMD in the mean change of QoL from baseline for the tamsulosin group versus the control group was 0.16 (95% CI; -0.16, 0.48). The regression analysis with the continuous variables (number of patients, study duration) revealed no significance in all outcomes as IPSS, QoL, and Qmax.

CONCLUSION

This study clarifies that tamsulosin 0.2 mg has similar efficacy and fewer adverse events compared with other alpha-blockers as an initial treatment strategy for men with lower urinary tract symptoms.

[Shugan Jieyu Capsules combined with conventional therapy for type III B prostatitis complicated by sexual dysfunction]

OBJECTIVE

To explore the clinical effect of Shugan Jieyu Capsules (SJC) on type III B prostatitis complicated by sexual dysfunction.

METHODS

A total of 98 patients with type III B prostatitis complicated by sexual dysfunction were equally randomized to a control and a trial group, the former treated with the combination of biofeedback/electrical stimulation and the α-blocker Tamsulosin Hydrochloride, and the latter with oral SJC in addition, both for 8 weeks. Before and after treatment, the severity of the symptoms was determined with NIH-CPSI, the patients'sexual function evaluated with CIPE-5 and IIEF-5, and their anxiety, depression and other psychological problems assessed with Hamilton Anxiety Scale (HAMA) and Hamilton Depression Rating Scale ( HAMD). The results were subjected to statistical analysis and compared between the two groups.

RESULTS

Statistically significant differences were found between the control and trial groups in the NIH-CPSI score (26.31 ± 7.91 vs 18.84 ± 6.63, P < 0.01), CIPE-5 premature ejaculation score (10. 41 ± 3.03 vs 14.37 ± 2.35, P < 0.05), IIEF-5 score (10.29 ± 3.97 vs 14.69 ± 4.19, P < 0.05), HAMA score (24.31 ± 1.78 vs 13.41 ± 4.21, P < 0.01), and HAMD score (25.24 ± 2.83 vs 14.49 ± 4.44, P < 0.01).

CONCLUSION

SJC can effectively relieve anxiety, depression and other psychological problems in type III B prostatitis patients with sexual dysfunction and improve their clinical symptoms as well.

[Comparison of the effectiveness of two different pharmacologic approaches to prevent intraoperative floppy iris syndrome]

OBJECTIVE

To compare the effectiveness of two strategies to prevent the appearance of intraoperative floppy iris syndrome (IFIS) in patients exposed to a-blockers.

METHODS

We compared retrospectively the presence and severity of the appearance of IFIS in 29 patients subjected to cataract surgery, establishing two groups of 12 patients (22 eyes) and 17 patients (33 eyes). The strategy applied to group one consisted of suspending the exposure to a-blockers for at least one week prior to the intervention, the topical application of 1% atropine three times a day for two days before the intervention and the use of intracameral lidocaine. The strategy for group two consisted of suspending use of the drug for at least one week before the intervention and the intracameral application at the beginning of surgery of a solution of physiological serum, adrenaline and lidocaine.

RESULTS

Six patients from group one showed no evidence of IFIS, 2 exhibited bilateral mild symptoms, 2 bilateral moderate and 2 unilateral severe symptoms of IFIS. In total, 45.5% eyes suffered from IFIS. In group two, only 3 eyes (9.1%) from 2 patients exhibited mild symptoms. Statistical analysis showed a significant difference between both groups (p=0.002). If only those exhibiting moderate and severe symptoms are taken into account the result was highly statistically significant (p=0.0002).

CONCLUSION

The study shows a greater statistical effectiveness of the strategy applied to group two compared to the strategy applied to group one (Arch Soc Esp Oftalmol 2009; 84: 549-556).

Pharmacodynamic profiles of different calcium channel blockers

The cardiovascular effects of different calcium channel blockers (CCB), exemplified by nifedipine, verapamil and diltiazem, are not identical. Some of these differences in effect may be due to the different CCBs interacting with different calcium channel subtypes in the tissues, and/or that the drug-receptor sites are separate. The drugs also have different abilities to activate the sympathetic nervous system, nifedipine increasing and diltiazem decreasing the baroreflex sensitivity. Verapamil, but not nifedipine and diltiazem, has a postjunctional alpha-adrenoceptor blocking effect, and can also increase the release of noradrenaline from adrenergic nerves by blocking pre-junctional alpha-adrenoceptors. In addition, verapamil may have a reserpine-like action on sympathetic nerves. The vasodilator actions of CCBs are not uniform, but seem to vary between species, different vascular regions, and different agents. Mechanisms other than blockade of influx of calcium from the extracellular medium have been suggested to explain these differences, including inhibition of intracellular calcium release, blockade of postjunctional alpha-adrenoceptors, interaction with calmodulin, inhibition of cyclic AMP phosphodiesterase, stimulation of Na+-, K+-activated ATPase, stimulation of a calcium pump, and a direct interaction with the contractile proteins. The heterogeneity in pharmacodynamic profile characterizing the CCBs is conspicuous, and may be of importance when selecting agents for the treatment of various cardiovascular and non-cardiovascular disorders.

The role of the alpha-adrenergic receptor in the leg vasoconstrictor response to orthostatic stress

AIM

The prompt increase in peripheral vascular resistance, mediated by sympathetic alpha-adrenergic stimulation, is believed to be the key event in blood pressure control during postural stress. However, despite the absence of central sympathetic control of the leg vasculature, postural leg vasoconstriction is preserved in spinal cord-injured individuals (SCI). This study aimed at assessing the contribution of both central and local sympathetically induced alpha-adrenergic leg vasoconstriction to head-up tilt (HUT) by including healthy individuals and SCI, who lack central sympathetic baroreflex control over the leg vascular bed.

METHODS

In 10 controls and nine SCI the femoral artery was cannulated for drug infusion. Upper leg blood flow (LBF) was measured bilaterally using venous occlusion strain gauge plethysmography before and during 30 degrees HUT throughout intra-arterial infusion of saline or the non-selective alpha-adrenergic receptor antagonist phentolamine respectively. Additionally, in six controls the leg vascular response to the cold pressor test was assessed during continued infusion of phentolamine, in order to confirm complete alpha-adrenergic blockade by phentolamine.

RESULTS

During infusion of phentolamine HUT still caused vasoconstriction in both groups: leg vascular resistance (mean arterial pressure/LBF) increased by 10 +/- 2 AU (compared with 12 +/- 2 AU during saline infusion), and 13 +/- 3 AU (compared with 7 +/- 3 AU during saline infusion) in controls and SCI respectively.

CONCLUSION

Effective alpha-adrenergic blockade did not reduce HUT-induced vasoconstriction, regardless of intact baroreflex control of the leg vasculature. Apparently, redundant mechanisms compensate for the absence of sympathetic alpha-adrenoceptor leg vasoconstriction in response to postural stress.

Treatment of benign prostatic hyperplasia at Mater Hospital, Nairobi

OBJECTIVE

To evaluate the use of medical therapy in the management of patients with mild, moderate and severe symptoms of benign prostatic hyperplasia.

DESIGN

Prospective study.

SETTING

Private urology clinic in Mater Hospital, Nairobi between 1995 and 2005.

PATIENTS

Six hundred and eighty patients with benign prostatic hypertrophy aged 50-80 years.

RESULTS

Two hundred and eighty (43.8%) patients benefited from the drug treatment alone and were released from the clinic follow up after five years. Two hundred and seventy (42.2%) cases could not complete the five years follow up on drugs alone due to symptoms recurrence or severity or unavailability of drugs. They were removed from the drugs alone treatment and put on other interventions. Ninety (15.9%) cases were operated on based on their decision and insistence or severity of their symptoms or no drugs response.

CONCLUSIONS

This observational study confirms that medical treatment is beneficial in the management of benign prostatic hyperplasia (BPH) and is cheap and gives better first line option of treatment choice to many patients. It also gives hopes to the surgical risk patients. The quality of life (QOL) of patients and their family disturbance is also improved.

A role of intravesical capsaicin instillation in benign prostatic hyperplasia with overactive bladder symptoms: the first reported study in the literature

OBJECTIVE

To study the treatment efficacy of capsaicin, in the cases of benign prostatic hyperplasia with overactive bladder symptoms.

MATERIAL AND METHOD

A prospective study of 20 benign prostatic hyperplasia patients whose overactive bladder symptoms were not improved by alpha1 blockers. All of them underwent intravesical capsaicin instillation at the Faculty of Medicine Siriraj Hospital, Bangkok, between 2004 and 2006. Both clinical and urodynamic data were evaluated before and after treatment.

RESULTS

Mean urgency decreased from 6.7 +/- 5.1 at baseline to 2.0 +/- 2.3 (p < 0.005), 1.4 +/- 2.4 (p < 0.005), and 1.3 +/- 2.2 (p < 0.005) at 1, 3, and 6 months. Mean urge incontinence decreaseD from 1.7 +/- 3.5 at baseline to 0.5 +/- 1.3 (p = 0.148), 0.4 +/- 1.2 (p = 0.114), and 0.3 +/- 1.1 (p = 0.085) at 1, 3, and 6 months. Mean urinary frequency decreased from 13.7 +/- 3.3 at baseline to 10.5 +/- 2.8 (p < 0.005), 9.6 +/- 2.0 (p < 0.005), and 9.5 +/- 2.6 (p < 0.005) at 1, 3, and 6 months. Mean nocturia decreased from 4.7 +/- 2.4 at baseline to 3.1 +/- 2.2 (p < 0.005), 2.7 +/- 1.2 (p < 0.005), and 2.9 +/- 1.6 (p < 0.005) at 1, 3, and 6 months. Mean first desire to void increased from 172.5 +/- 100.4 ml at baseline to 210.6 +/- 99.5 ml (p = 0.016) at 1 month. Mean maximal cystometric capacity increased from 350.3 +/- 165.9 ml at baseline to 397.4 +/- 165.7 ml (p = 0.012) at 1 month. Peak flow rate, detrusor pressure, and post void residual urine were not affected No serious adverse effect occurred in this study.

CONCLUSION

Intravesical capsaicin instillation is an effective treatment for overactive bladder symptoms in benign prostatic hyperplasia patients.

The Emerging Epidemic of Methamphetamine-Induced Aortic Dissections

The clinical presentation, treatment, and outcomes of six consecutive patients presenting with acute aortic dissection secondary to hypertensive crises from methamphetamine use is described. Data were obtained prospectively from the expanded STS clinical database of the division of cardiothoracic surgery at the University of Washington, but reviewed in a retrospective fashion. These patients represent 5.5% of all patients diagnosed and treated for aortic dissection in the same time period (6/109) and 20% of all patients with aortic dissection under the age of 50 years (6/30). We conclude that young patients (<age 50 years old) presenting with acute aortic dissections should be routinely tested for methamphetamine. Positive urine tests should be confirmed with chromatography-mass spectrometry (GC-MS). Beta and alpha blockers should be used instead of the more typical beta blockade alone. We recommend the addition and documentation of intense, long-term drug rehabilitation program along with routine periodic clinical and radiographic follow-up to prevent secondary aneurysmal dilation of remaining pathological aorta.

Effect of Sildenafil and Rolipram on Adrenergic Responses in Isolated Human and Monkey Corpus Cavernosum

OBJECTIVE

Evaluate and compare effects of phosphodiesterase inhibitors (PDEIs), sildenafil and rolipram, on adrenergic contractile responses of human and monkey cavernosal smooth muscle.

METHODS

Human penises were obtained from patients undergoing gender reassignment surgery. Isolated human and monkey corpus cavernosum (CC) strips were suspended in tissue bath chambers for isometric tension experiments. The effects of the drugs on precontracted monkey and human CC and neurogenic contractions in human CC were investigated.

RESULTS

Both sildenafil and rolipram induced concentration-dependent relaxations of human and monkey CC strips precontracted with noradrenaline (NA). The IC(50) values, determined by reverse regression for nitroglycerin (NTG), isoprenaline, and sildenafil in monkey CC, were, respectively, 1.5+/-0.9x10(-7) M, 3.7+/-0.6x10(-6) M, and 1.7+/-0.7x10(-5) M. Similarly, in human CC muscle, sildenafil was weaker than NTG as a muscle relaxant. Sildenafil, 1.5 microM, reduced neurogenic contractions in human CC due to stimulation of predominantly adrenergic nerves. The suppressant effect of sildenafil on adrenergic transmission was attenuated in CC strips pretreated with N omega-nitro-L-arginine and overcome with a higher stimulus frequency or tetraethylammonium. Rolipram partially inhibited adrenergic excitatory response but without significantly affecting NA-induced contraction.

CONCLUSIONS

Sildenafil and rolipram induced concentration-dependent reversal of human and monkey CC tone mediated by NA. Both PDEIs attenuated contractile adrenergic response of human CC to electrical stimulation. The results also underline the importance of the cyclic adenosine monophosphate-dependent signalling pathway in regulating the tone. PDE4 inhibition in CC is an additional mechanism for erection and potential therapeutic adjunct.

JP-1302: a new tool to shed light on the roles of alpha2C-adrenoceptors in brain

The discovery of JP-1302 as a selective, high affinity antagonist at the alpha2C-adrenoceptor will enable researchers to probe the functional role and address the therapeutic utility of this potentially highly important adrenoceptor subtype.

Frequency and pattern dependence of adrenergic and purinergic vasoconstriction in rat skeletal muscle arteries

Sympathetic nerves fire in bursts followed by brief periods of quiescence. Periods of quiescence may be a valuable part of coding for different neurotransmitters. We compared adrenergic- and non-adrenergic-mediated vasoconstriction with repeating burst patterns versus constant frequency stimulation. Seventeen rats were killed, and the femoral arteries dissected out and mounted in organ tissue baths at 37 degrees C and pH 7.4. Field stimulation was applied to artery rings from five rats at constant frequencies of 2-6 Hz for 144 impulses. In 12 rats, artery rings were stimulated with two burst pattern protocols consisting of repeating pairs, triplets, quadruplets or sextuplets performed using either 8 or 30 Hz as the instantaneous frequency for a total of 144 impulses. All protocols were repeated with the P2 purinergic antagonist pyridoxal-phosphate-6-azophenyl-2'4'-disulphonic acid (PPADs; 0.42 m) or the alpha(1)-antagonist prazosin (1.59 microM). Tension was decreased by the addition of the P2 antagonist PPADs (P < 0.05). Prazosin abolished tension at all constant frequencies (P < 0.05). P2 and alpha(1)-antagonism decreased tension with 8 and 30 Hz burst pattern field stimulation. However, the magnitude of decrease in tension with prazosin was less with burst patterns compared to the same average constant frequencies (P < 0.05). It appears that P2X receptors and alpha(1)-receptors in the femoral artery are sensitive to frequency and patterns of electrical stimulation.

Antidepressant-like activity of n-hexane extract of nutmeg (Myristica fragrans) seeds in mice

The present study was undertaken to investigate the effect of an n-hexane extract of Myristica fragrans seeds on depression in mice by using the forced swim test (FST) and the tail suspension test (TST). M. fragrans extract (5, 10, and 20 mg/kg) was administered orally for 3 successive days to different groups of Swiss male young albino mice. M. fragrans extract significantly decreased immobility periods of mice in both the FST and the TST. The 10 mg/kg dose was found to be most potent, as indicated by the greatest decrease in the immobility period compared with the control. Furthermore, this dose of the extract was found to have comparable potency to imipramine (15 mg/kg i.p.) and fluoxetine (20 mg/kg i.p.). The extract did not have a significant effect on locomotor activity of mice. Prazosin (62.5 microg/kg i.p.; an alpha (1)-adrenoceptor antagonist), sulpiride (50 mg/kg i.p.; a selective D(2) receptor antagonist), and p-chlorophenylalanine (100 mg/kg i.p.; an inhibitor of serotonin synthesis) significantly attenuated the M. fragrans extract-induced antidepressant-like effect in the TST. Thus, extract of M. fragrans elicited a significant antidepressant-like effect in mice, when assessed in both the TST and the FST. The antidepressant-like effect of the extract seems to be mediated by interaction with the adrenergic, dopaminergic, and serotonergic systems.

Are generic formulations of carvedilol of inferior pharmaceutical quality compared with the branded formulation?

INTRODUCTION

Carvedilol is a comprehensive beta(1)-, beta(2)-, and alpha(1)-adrenoreceptor blocker marketed as Dilatrend by F. Hoffmann-La Roche Ltd. (Roche) and as Coreg by GlaxoSmithKline for the treatment of hypertension, stable angina pectoris, post myocardial infarction with left ventricular dysfunction and all degrees of symptomatic chronic heart failure.

OBJECTIVES

In this report, the pharmaceutical qualities of Dilatrend 6.25 mg, 12.5 mg and 25 mg tablets and 35 randomly selected carvedilol generic products from 20 manufacturers in 19 countries have been assessed according to the European Pharmacopoeia and the Roche specifications.

METHODS

The generic products were subjected to four key tests: carvedilol content, tablet hardness, tablet dissolution and purity.

RESULTS

All three Dilatrend strengths conformed to specifications. At least 17/35 (48.6%) generic products failed the specifications due to: incorrect mean carvedilol content (outside 95-105%) - three products; excess impurities (> 0.3%) - one product; incorrect tablet hardness (outside 30-70 N) - 11 products; inadequate dissolution (< 75% in 30 min) - nine products. Seven products (20%) failed two tests, generally hardness and dissolution.

CONCLUSION

The dose-for-dose substitution of the original formulation of carvedilol (Dilatrend) with a pharmaceutically different, and possibly inferior, generic copy may conceivably result in a change in the efficacy of the treatment, because of an unanticipated change in pharmacokinetics or bioequivalence, and/or in a change in tolerability due to impurities.

Sexual dimorphism in the renin-angiotensin system in aging spontaneously hypertensive rats

In young adult spontaneously hypertensive rats (SHR), mean arterial pressure (MAP) is higher in males than in females and inhibition of the renin-angiotensin system (RAS) eliminates this sex difference. After cessation of estrous cycling in female SHR, MAP is similar to that in male SHR. The purpose of this study was to determine the role of the RAS in maintenance of hypertension in aging male and female SHR. At 16 mo of age, MAP was similar in male and female SHR (183+/-5 vs. 193+/-8 mmHg), and chronic losartan (40 mg.kg-1.day-1 po for 3 wk) reduced MAP by 52% (to 90+/-8 mmHg, P<0.05 vs. control) in males and 37% (to 123+/-11 mmHg, P<0.05 vs. control) in females (P<0.05, females vs. males). The effect of losartan on angiotensin type 1 (AT1) receptor blockade was similar: MAP responses to acute doses of ANG II (62.5-250 ng/kg) were blocked to a similar extent in losartan-treated males and females. F2-isoprostane excretion was reduced with losartan more in males than in females. There were no sex differences in plasma renin activity, plasma angiotensinogen or ANG II, or renal expression of AT1 receptors, angiotensin-converting enzyme, or renin. However, renal angiotensinogen mRNA and protein expression was higher in old males than females, whereas renal ANG II was higher in old females than males. The data show that, in aging SHR, when blood pressures are similar, there remains a sexual dimorphism in the response to AT1 receptor antagonism, and the differences may involve sex differences in mechanisms responsible for oxidative stress with aging.

Potential vascular α1-adrenoceptor blocking properties of an array of 5-HT receptor ligands in the rat

This study set out to analyse the potential ability of some 5-hydroxytryptamine (5-HT) receptor ligands widely used in cardiovascular experimental models to interact with vascular alpha1-adrenoceptors in the pithed rat. These ligands included: methiothepin, methysergide and metergoline (5-HT(1)/5-HT2); WAY-100635, buspirone, ipsapirone and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (5-HT(1A)); GR127935 (5-HT(1B/1D)); ketanserin, ritanserin, spiperone and pizotifen (5-HT2); granisetron and metoclopramide (5-HT3); tropisetron (5-HT3/5-HT4); ergotamine (5-HT(1B/1D), 5-ht(5A/5B)); clozapine (5-HT6/5-HT7); as well as LY215840 and mesulergine (5-HT2/5-HT7). For this purpose, the increases in diastolic blood pressure produced by the selective alpha1-adrenoceptor agonist, phenylephrine, were analysed before and after the above antagonists or saline. The adrenoceptor antagonist properties of prazosin (alpha1) and yohimbine (alpha2) were also analysed for comparison. Thus, the phenylephrine-induced vasopressor responses were dose-dependently antagonised with the following apparent rank order of potency by: prazosin > or = methiothepin > ketanserin > clozapine > or = lisuride >> buspirone; this potency correlates with the affinity of these compounds for alpha1-adrenoceptor binding sites. In contrast, the other compounds were either devoid of any blocking effect on--or even potentiated (i.e. lisuride, methysergide, 8-OH-DPAT, granisetron and GR127935)--the responses to phenylephrine. These results show that methiothepin, ketanserin, clozapine, lisuride and buspirone can block alpha1-adrenoceptors in the rat systemic vasculature.

Assessment of cognitive function in patients with essential hypertension treated with lercanidipine

OBJECTIVES

The aim of this longitudinal, open-label, comparative, multicenter study was to assess cognitive function in hypertensive patients receiving mid-term treatment with lercanidipine.

METHODS

Hypertensive patients aged 40 years or older were treated with lercanidipine (10 mg daily) after 7-10 days washout period. The duration of the study was 6 months. Blood pressure (BP) was measured every 4 weeks (JNC 6th report). In patients with inadequate BP control, doxazosin was added and up-titrated. At baseline and after 6 months of treatment, cognitive function was evaluated using the Spanish validated version of the Mini-Mental State Examination (MMSE) and the Trail Making Test (TMT).

RESULTS

In the study population of 467 patients, BP decreased from 154.4/95.3 mmHg at baseline to 134.8/80.7 mmHg at 6 months. At the end of the study, 98% of patients were receiving lercanidipine, 20% an angiotensin-converting enzyme inhibitor, and 6% doxazosin. Adequate BP control was obtained in 68% of patients. The mean (standard deviation) MMSE scores improved from 32.35 (2.59) to 33.25 (2.36) (p < 0.0001). Patients with good BP control scored significantly better than those with inadequate BP control (p < 0.05), which was already observed at the first month.

CONCLUSIONS

The third-generation calcium channel antagonist, lercanidipine, improved cognitive function after 6 months of treatment especially in patients with good BP control, suggesting that improvements in cognitive function may be associated with a decrease in BP.

Attenuation of visceral nociception by alpha- and beta-amyrin, a triterpenoid mixture isolated from the resin of Protium heptaphyllum, in mice

In the search for novel natural compounds effective against visceral nociception, the triterpenoid mixture alpha- and beta-amyrin, isolated from Protium heptaphyllum resin, was assessed in two established mouse models of visceral nociception. Mice were pretreated orally with alpha- and beta-amyrin (3, 10, 30, and 100 mg/kg) or vehicle, and the pain-related behavioral responses to intraperitoneal cyclophosphamide or to intracolonic mustard oil were analyzed. The triterpenoid mixture showed a dose-related significant antinociception against the cyclophosphamide-induced bladder pain, and at 100 mg/kg, the nociceptive behavioral expression was almost completely suppressed. Intracolonic mustard oil-induced nociceptive behaviors were maximally inhibited by 10 mg/kg alpha- and beta-amyrin mixture in a naloxone-reversible manner. While pretreatment with ruthenium red (3 mg/kg, s. c.), a non-specific transient receptor potential cation channel V1 (TRPV1) antagonist, also caused significant inhibition, the alpha (2)-adrenoceptor antagonist, yohimbine (2 mg/kg, s. c.), showed no significant effect. The triterpene mixture (10 mg/kg, p. o.) neither altered significantly the pentobarbital sleeping time, nor impaired the ambulation or motor coordination in open-field and rotarod tests, respectively, indicating the absence of sedative or motor abnormalities that could account for its antinociception. These results indicate that the antinociceptive potential of alpha- and beta-amyrin possibly involves the opioid and vanilloid (TRPV1) receptor mechanisms and further suggests that it could be useful to treat visceral pain of intestinal and pelvic origins.

Effect of terazosin on tissue vascularity and apoptosis in transitional cell carcinoma of bladder

OBJECTIVES

To present a pilot study to determine whether the alpha1-adrenoceptor antagonist terazosin can induce apoptosis in transitional cell carcinoma (TCC) of the bladder, similar to the effect seen with prostate cancer. The alpha1-adrenoceptor antagonist terazosin has recently been shown to induce apoptosis in prostate cancer cells both in vitro and in vivo and to reduce prostatic tissue vascularity by potentially affecting endothelial cell adhesion.

METHODS

The records of 24 men who underwent radical cystectomy for TCC of the bladder at the Lexington Veterans Affairs Medical Center were reviewed. The control group consisted of 15 men who were never exposed to terazosin. The study group consisted of 9 men who were treated with terazosin before cystectomy. Sections of the bladder tumor and normal trigone were subjected to immunohistochemical analysis for microvessel density, endothelial cell CD31 expression, and apoptosis detection (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling), as well as high-molecular-weight cytokeratin staining.

RESULTS

A significant reduction in tissue vascularity (14.0 versus 19.2, P <0.05) and a significant increase in the apoptotic index (3.0% versus 1.7%, P <0.05) was detected in terazosin-treated bladder tumors compared with untreated bladder tumors. Most TCC specimens (80%) exhibited strong and consistently uniform immunostaining for high-molecular-weight cytokeratin staining.

CONCLUSIONS

These results suggest that terazosin reduces tumor vascularity and induces apoptosis in TCC of the bladder. Additional studies with more patients are necessary to reach definitive conclusions. However, considering the proven apoptotic action of terazosin in prostatic tissue, this study may have implications for the use of terazosin in the treatment of bladder TCC.

A review of controlled trials in the pharmacological treatment of premature ejaculation

Premature ejaculation is a common sexual problem which presents to genitourinary (GU) medicine services. Five main treatment approaches have been used in clinical trials: behavioural therapy, antidepressants, phosphodiesterase-5 (PDE5) inhibitors, topical anaesthetic agents and alpha-blockers. We have carried out a systematic review of published pharmacological trials. All antidepressants appeared to delay ejaculation to some extent at all doses. Anaesthetic creams appeared to be as successful in slowing ejaculation as antidepressants without systemic side-effects, although some patients did experience erectile problems or unpleasant local symptoms. Anecdotally, behavioural therapy is effective and appears to have long-lasting efficacy. There is a need for quality comparative trial of behavioural therapy, topical anaesthetic agents and antidepressants, including appropriate measures of relapse, follow-up and acceptability of continuing long-term treatment.

THE COMPARISON AND EFFICACY OF 3 DIFFERENT α1-ADRENERGIC BLOCKERS FOR DISTAL URETERAL STONES

PURPOSE

alpha1-Adrenergic blockers have recently been shown to increase the rate of spontaneous passage of distal ureteral stones. We compared efficacy of 3 different alpha1-adrenergic blockers for this purpose.

MATERIALS AND METHODS

A total of 114 patients between 18 and 65 years old who had lower ureteral stones were included in the study. Patients were randomly divided into 4 groups. Group 1 consisted of 28 patients and acted as the control group. Group 2 comprised 29 patients who received tamsulosin, group 3 was 28 patients receiving terazosin and group 4 was 29 patients receiving doxazosin. These agents were given for up to a month and hydration was also recommended simultaneously. Every week patients were controlled with x-rays of the kidneys, ureters, bladder and urinary ultrasonography. Meanwhile the number of pain episodes, analgesic dosage and the number of days for spontaneous passage of the calculi through the ureter were also recorded.

RESULTS

There were no differences between the groups with respect to age, weight, height, sex and stone size. The calculi passed through the ureter spontaneously in 15 patients in group 1 (53.57%), in 23 patients in group 2 (79.31%), in 22 patients in group 3 (78.57%), and in 22 patients in group 4 (75.86%). In groups 2 to 4 the number of pain episodes, expulsion time and analgesic dosage were found to be lower compared with those in group 1.

CONCLUSIONS

alpha1-Adrenergic blockers increase the frequency of spontaneous passage of the distal ureteral calculi. All 3 agents tested were equally efficacious.

Selective inhibition of alpha1A-adrenergic receptor signaling by RGS2 association with the receptor third intracellular loop

Regulators of G-protein signaling (RGS) proteins act directly on Galpha subunits to increase the rate of GTP hydrolysis and to terminate signaling. However, the mechanisms involved in determining their specificities of action in cells remain unclear. Recent evidence has raised the possibility that RGS proteins may interact directly with G-protein-coupled receptors to modulate their activity. By using biochemical, fluorescent imaging, and functional approaches, we found that RGS2 binds directly and selectively to the third intracellular loop of the alpha1A-adrenergic receptor (AR) in vitro, and is recruited by the unstimulated alpha1A-AR to the plasma membrane in cells to inhibit receptor and Gq/11 signaling. This interaction was specific, because RGS2 did not interact with the highly homologous alpha1B- or alpha1D-ARs, and the closely related RGS16 did not interact with any alpha1-ARs. The N terminus of RGS2 was required for association with alpha1A-ARs and inhibition of signaling, and amino acids Lys219, Ser220, and Arg238 within the alpha1A-AR i3 loop were found to be essential for this interaction. These findings demonstrate that certain RGS proteins can directly interact with preferred G-protein-coupled receptors to modulate their signaling with a high degree of specificity.

Amygdala and "emotional" modulation of the relative use of multiple memory systems

The basolateral amygdala modulates the cognitive and habit memory processes mediated by the hippocampus and caudate nucleus, respectively. The present experiments used a plus-maze task that can be acquired using either hippocampus-dependent "place" learning or caudate-dependent "response" learning to examine whether peripheral or intra-basolateral amygdala injection of anxiogenic drugs would bias rats towards the use of a particular memory system. In Experiment 1, adult male Long-Evans rats were trained to swim from the same start point to an escape platform located in a consistent goal arm, and received pre-training peripheral injections of the alpha(2)-adrenoceptor antagonists yohimbine (2.5 or 5.0 mg/kg), RS 79948-197 (0.05, 0.1, or 0.2 mg/kg), or vehicle. On a drug-free probe trial from a novel start point administered 24h following acquisition, vehicle treated rats predominantly displayed hippocampus-dependent place learning, whereas rats previously treated with yohimbine (2.5, 5.0 mg/kg) or RS 79948-197 (0.1 mg/kg) predominantly displayed caudate-dependent response learning. In Experiment 2, rats receiving pre-training intra-basolateral amygdala infusions of RS 79948-197 (0.1 microg/0.5 microl) also predominantly displayed response learning on a drug-free probe trial. The findings indicate (1) peripheral injections of anxiogenic drugs can influence the relative use of multiple memory systems in a manner that favors caudate-dependent habit learning over hippocampus-dependent cognitive learning, and (2) intra-basolateral amygdala infusion of anxiogenic drugs is sufficient to produce this modulatory influence of emotional state on the use of multiple memory systems.

Correlation between penile duplex findings and stress electrocardiography in men with erectile dysfunction

The aim of this work is to assess the association between vasculogenic erectile dysfunction (ED) and coronary artery disease in men above the age of 40 y. The study included 40 patients above 40 y of age with vasculogenic ED of more than 3 months duration. A dynamic duplex study after intracavernosal injection of a bimix solution (60 mg papaverine + 2 mg phentolamine mesylate) was carried out using a color ultrasound machine. The patients underwent a stress ECG test, carried out on a motor-driven treadmill according to the 'Bruce Protocol'. A total of 12 patients were diagnosed with positive ischemic heart disease (IHD). Their mean peak systolic velocity (PSV) was PSV = 19.58 cm/s. In all, patients were diagnosed with negative IHD; their mean PSV was 36.21 cm/s. A statistically significant difference was observed between patients with positive IHD and patients with negative IHD regarding PSV (P = 0.003). The sensitivity of a PSV of less than 35 cm/s in predicting IHD was 50% with a specificity of 100%. Positive predictive value for abnormal stress ECG to predict a PSV of less than 35 cm/s was 100%. In conclusion, the PSV of cavernosal arteries is a reliable measure for predicting IHD in patients with vasculogenic ED. Patients with a PSV of less than 35 cm/s should be referred for cardiologic assessment as they carry a real risk of having silent IHD.

Efficacy of open-label venlafaxine in subjects with major depressive disorder: associations with neuroendocrine response to serotonergic and noradrenergic probes

An open-label pilot study explored the relationship between severity of depressive symptoms and venlafaxine dose required for clinical efficacy in outpatients with major depressive disorder (MDD). The utility of the neuroendocrine response to serotonergic (ipsapirone) and noradrenergic (clonidine) probes as predictors of venlafaxine dosage required for effective treatment was also explored. Nineteen medically healthy medication-free outpatients over 18 years of age who met criteria for MDD were studied. Participants received either a 20-mg dose of ipsapirone orally, a 0.002-mg/kg intravenous dose of clonidine, or placebo. Following a 1-week single-blind placebo lead-in, all subjects were treated with immediate release venlafaxine. Low-dose responders were defined as those subjects experiencing a >50% decrease in depression score on 37.5 mg, b.i.d., and high-dose responders were defined as those subjects experiencing similar improvement on venlafaxine doses of 75 mg, b.i.d., or higher. Subjects responding to low-dose treatment had a lower mean baseline Hamilton depression score than subjects requiring high-dose treatment. Neuroendocrine and temperature responses to clonidine or ipsapirone challenges were not significantly different in the high- vs. low-dose responders. Evaluation of models of "serotonergic-responsive" and norepinephrine-responsive" depression requires larger numbers of patients.

Novel phosphodiesterase type 5 inhibitors: assessing hemodynamic effects and safety parameters

The relaxing effect of the phosphodiesterase type 5 (PDE5) inhibitors on vascular smooth muscle has attracted much attention, especially in persons with cardiovascular disease. The results of early studies showed that sildenafil slightly reduces systolic and diastolic blood pressures and has no effect on heart rate, while being safe and well tolerated. Studies also indicate that sildenafil does not contribute to the development of myocardial infarction or ischemia. Similar benign effects on hemodynamics and cardiac events have also been demonstrated for tadalafil and vardenafil. None of the PDE5 inhibitors adversely affects total exercise time or time to ischemia during exercise testing in men with stable angina. It is key to avoid concomitant administration of nitrates with any of the PDE5 inhibitors, because this combination can cause increased vasodilation and a subsequent drop in blood pressure. Sildenafil has an alpha-blocker precaution; tadalafil is contraindicated with alpha blockers except for 0.4 mg tamsulosin; vardenafil is contraindicated with alpha blockers.