Effects of ovariectomy and estrogen and androgen treatment on sildenafil-mediated changes in female genital blood flow and vaginal lubrication in the animal model.

OBJECTIVE: Our purpose was to investigate the effects of ovariectomy and estradiol and testosterone treatment on sildenafil- induced changes in genital hemodynamics and vaginal lubrication. STUDY DESIGN: Female New Zealand White rabbits were either kept intact or underwent ovariectomy. Two weeks after ovariectomy, animals were treated with vehicle, testosterone, or a combination of estradiol and testosterone for 14 days. Genital hemodynamics and vaginal lubrication were recorded at the end of the treatment period. RESULTS: Ovariectomy caused a marked decrease in vaginal lubrication but did not significantly alter genital hemodynamics. In contrast to testosterone treatment of ovariectomized animals, estradiol treatment significantly increased genital blood flow and vaginal lubrication above that observed in control animals.Sildenafil Citrate (Viagra) administration caused a significant increase in genital hemodynamics irrespective of the hormonal status. CONCLUSION: This study suggests that estradiol but not testosterone modulates genital hemodynamics and thatSildenafil Citrate (Viagra) enhances genital blood flow irrespective of hormonal status

Long-term intracavernous therapy responders can potentially switch to Sildenafil Citrate (Viagra) after radical prostatectomy.

OBJECTIVES: To assess whether long-term users of intracavernous (IC) injections after radical prostatectomy can switch to oral therapy with Sildenafil Citrate (Viagra). METHODS: Forty-nine patients (mean age 60.9 years) with Erectile Dysfunction after radical prostatectomy were identified as long-term users of IC injections (3.7 +/- 1.9 years). These patients received open-label treatment with Sildenafil Citrate (Viagra) (50 to 100 mg) for a minimum of 4 weeks or five attempts. The primary outcome measure of our study was assessed by the Sexual Health Inventory of Men (SHIM) questionnaire (International Index of Erectile Function-5 [IIEF]). A successful switch was prospectively defined as erection sufficient for vaginal penetration afterSildenafil Citrate (Viagra) use and compliance to therapy. Patients were designated as responders or nonresponders on the basis of their ability to achieve vaginal penetration. RESULTS: Of 49 patients, only 36 agreed to receive oral open-labelSildenafil Citrate (Viagra) (50 to 100 mg) for a minimum of 4 weeks or five attempts. Prostaglandin E1 (PGE1) was used in 70% and triple therapy (PGE1, papaverine, and phentolamine) in the remaining 30%. Of the 36 patients, 15 (41%) successfully switched toSildenafil Citrate (Viagra) and discontinued IC injections. When the results were stratified by the type of IC solution, patients with high-dose triple therapy had a poor success rate of switch (7%) compared with patients using PGE1 treatment (67%). Of the 36 patients, 14 (38%) foundSildenafil Citrate (Viagra) ineffective and continued using IC injections. Patients who switched to oral therapy had had a greater (P <0.001) total mean SHIM (IIEF-5) score with IC injections than those who did not switch (12.3 +/- 7.8 versus 20.0 +/- 4.9). Of the 36 patients, 7 (19%) foundSildenafil Citrate (Viagra) alone to be suboptimal but continued using it, enhancing the efficacy of IC injections alone. The three predictive factors for a successful switch were high preoperative SHIM (IIEF-5) score, high post-IC injection SHIM score, and type of IC medication used (PGE1 alone versus high-dose triple therapy). CONCLUSIONS: Long-term users of IC injection therapy can potentially switch to Sildenafil Citrate (Viagra) with acceptable sexual satisfaction. Patients will accept a lower degree of sexual satisfaction as measured by the IIEF-5 (SHIM) score if oral therapy is effective

Effects ofSildenafil Citrate (Viagra) on ocular perfusion demonstrated by color Doppler ultrasonography.

The aim of this study was to investigate the effects ofSildenafil Citrate (Viagra) on ocular hemodynamics by color Doppler ultrasonography (CDU). In all, 38 patients with Erectile Dysfunction diagnosed by International Index of Erectile Function (IIEF) and Sexual Health Inventory of Men (SHIM) scores were included into the study. After taking 100 mg of oral Sildenafil Citrate (Viagra), all patients underwent CDU examination of central retinal artery at 60 and 75 min and CDU examination of cavernosal artery at 20, 60 and 75 min. All of the side effects during and after the test were also recorded. The mean cavernous artery peak systolic flow velocity increased significantly after sildenafil. However, no significant change was determined in central retinal artery flow parameters including peak systolic flow velocity, end-diastolic flow velocity, resistive index, pulsatility index, volume and diameter. Five patients experienced ocular side effects. No significant change was observed in retinal artery CDU measurements of patients having ocular side effects.Sildenafil Citrate (Viagra) has no effect on ocular hemodynamics on the basis of CDU. Ocular side effects may be the result of other changes in retinal photoreceptors rather than the ocular circulation

Effect ofSildenafil Citrate (Viagra) on ocular haemodynamics.

PURPOSE: To study the effect of sildenafil, which is an effective agent for the treatment of Erectile Dysfunction, on ocular haemodynamics. METHODS: In this prospective study we examined the effect of a single oral dose of 50 mg Sildenafil Citrate (Viagra) in a group of healthy young male volunteers, by using colour Doppler ultrasound imaging to measure haemodynamic variables in the central retinal artery (CRA), short temporal posterior ciliary artery (STPCA) and ophthalmic artery (OA). The following examinations were performed on both eyes immediately before and 1 h after a single oral dose of 50 mg sildenafil: visual acuity, intraocular pressure (IOP), colour vision, anterior segment, fundus appearance, resting heart rate, blood pressure and colour Doppler measurements. RESULTS: AfterSildenafil Citrate (Viagra) administration, peak systolic velocity, mean velocity and end-diastolic velocity significantly increased in the OA of both eyes. All Dopper indices remained non-significant for the CRA and STPCA of both eyes.Sildenafil Citrate (Viagra) did not cause any significant change in IOP, colour vision, visual acuity, systolic blood pressure or diastolic blood pressure. However, heart rate measurements increased significantly afterSildenafil Citrate (Viagra) administration compared with baseline (p = 0.003). CONCLUSION: The increased flow velocity in the ophthalmic artery seems to be due to a vasodilator effect ofSildenafil Citrate (Viagra)

Patterns of use ofSildenafil Citrate (Viagra) among commercially insured adults in the United States: 1998-2002.

Sildenafil is increasingly being marketed to younger healthcare consumers. The purpose of this study was to profileSildenafil Citrate (Viagra) use in commercially insured, adult beneficiaries. Annual ambulatory prescription claims data from 1998 to 2002, for a nationwide, random sample of over 5 million life-years of commercially insured adults (aged > or =18 y), were examined retrospectively. The overall prevalence ofSildenafil Citrate (Viagra) use increased from 0.8% (1998) to 1.4% (2002), an 84% increase. While the growth in use slowed in older males, use became more pronounced in younger males and females and decreased in older females. The fastest growing segment of users was found to be males aged 18-45 y. The proportion of users who had two or more claims for a medication that is suspected of inducing Erectile Dysfunction (ED) and/or a marker for a suspected ED-inducing disease decreased over the study period. Our findings suggest that use may increase among younger male and female patients and those without an underlying etiologic reason for use

Cost utility analysis ofSildenafil Citrate (Viagra) compared with papaverine-phentolamine injections.

OBJECTIVE: To compare the cost effectiveness ofSildenafil Citrate (Viagra) and papaverine-phentolamine injections for treating Erectile Dysfunction. DESIGN: Cost utility analysis comparing treatment withSildenafil Citrate (Viagra) (allowing a switch to injection therapy) and treatment with papaverine-phentolamine (no switch allowed). Costs and effects were estimated from the societal perspective. Using time trade-off, a sample of the general public (n=169) valued health states relating to Erectile Dysfunction. These values were used to estimated health related quality of life by converting the clinical outcomes of a trial into quality adjusted life years (QALYs). PARTICIPANTS: 169 residents of Rotterdam. MAIN OUTCOME MEASURES: Cost per quality adjusted life year. RESULTS: Participants thought that Erectile Dysfunction limits quality of life considerably: the mean utility gain attributable toSildenafil Citrate (Viagra) is 0.11. Overall, treatment withSildenafil Citrate (Viagra) gained more QALYs, but the total costs were higher. The incremental cost effectiveness ratio for the introduction ofSildenafil Citrate (Viagra) was pound sterling 3639 in the first year and fell in following years. Doubling the frequency of use ofSildenafil Citrate (Viagra) almost doubled the cost per additional QALY. CONCLUSIONS: Treatment withSildenafil Citrate (Viagra) is cost effective. When considering funding sildenafil, healthcare systems should take into account that the frequency of use affects cost effectiveness

Sildenafil does not change coronary flow reserve in diabetics with Erectile Dysfunction

BACKGROUND AND AIM OF STUDY: Disturbance of the microvascular coronary circuit is common in diabetics with Erectile Dysfunction. We investigated effects ofSildenafil Citrate (Viagra) on coronary flow reserve (CFR) of the left anterior descending branch. PATIENTS AND METHODS: 43 diabetics (aged 59 +/- 7 years) with Erectile Dysfunction and without symptoms of coronary artery disease were selected. Cardiac diagnosis, including stress ECG and echocardiography was performed in all. Because of the clinical suspicion of coronary artery disease coronary angiography was performed in 16 of them. Severe coronary artery disease was confirmed in 12 patients who were excluded from further analyses as well as 10 diabetics in whom coronary flow measurements were not possible. In the other 21 diabetics, adenosine-mediated CFR was calculated at baseline and 1 hour after ingestion of 50 mgSildenafil Citrate (Viagra) by transthoracic Doppler echocardiography. RESULTS: CFR at baseline was at the lower level of the normal range in 17/21 diabetics (median 245 %, range 210 - 490 %). CFR decreased insignificantly in 12/21 patients afterSildenafil Citrate (Viagra) administration (Delta CFR -10 %, p = 0.3). Patients with a body mass index > 25 kg/m(2), and left ventricular hypertrophy had the highest reduction of CFR after sildenafil, but a drop of the CFR below 200 % was not observed in any patient. Systemic blood pressure dropped significantly from 130/80 mmHg to 120/72 mmHg (p < 0.002). CONCLUSION: Diabetics with Erectile Dysfunction often have a CFR in the lower range of normal.Sildenafil Citrate (Viagra) did not further reduce CFR. Asymptomatic, severe coronary artery disease often can be found in diabetics with Erectile Dysfunction. Cardiological screening for contraindications forSildenafil Citrate (Viagra) seems mandatory in diabetics with a high cardiovascular risk profile

Potential for use of pulse wave analysis in determining the interaction betweenSildenafil Citrate (Viagra) and glyceryl trinitrate.

BACKGROUND: The early part of the central aortic pressure pulse, with amplitude (PI - Pd), is generated by left ventricular ejection, while the latter part (or augmented pressure), with amplitude (Ps - Pi), is generated by the reflected wave arriving during systole. The effects of arterial vasodilator agents, especially nitrates, on central aortic systolic blood pressure are grossly underestimated by sphygmomanometric measurements of brachial artery pressure. HYPOTHESIS: The objective of this study was to investigate the potential for use of central arterial pulse wave analysis, obtained noninvasively from the radial pulse, in determining the interaction betweenSildenafil Citrate (Viagra) and the nitric oxide donor drug glyceryl trinitrate (GTN). METHODS: Central aortic pressure waveforms were generated from noninvasively measured radial artery pressure wave-forms and subjected to pulse wave analysis to determine the interaction betweenSildenafil Citrate (Viagra) and transdermally applied GTN. RESULTS: Transdermal GTN (2.5, 5.0, and 15 mg per 24-h patches) alone caused no consistent change in sphygmomanometer-determined systolic or diastolic pressures, but there was a consistent, dose-related fall in amplitude of the augmented systolic pressure, (Ps - Pi), of 4.0, 7.0, and 11 mmHg, respectively, with little change in diastolic pressure. The 2.5 mg patch caused a fall of 4.0 mmHg in aortic systolic pressure, while augmentation index (AIx) fell from 20 to 11% and pulse pressure fell 18%. When oralSildenafil Citrate (Viagra) (50 mg) was administered after GTN (2.5 mg), aortic systolic pressure fell another 4.0 mmHg. This decrease in systolic pressure caused a fall in AIx to almost 0.0%; pulse pressure fell another 9.0%. CONCLUSION: These modifications in aortic systolic and pulse pressure are due primarily to reduction in wave-reflection amplitude and are not detected by sphygmomanometer-measured brachial artery pressure