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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We hypothesized that chronic oral administration of the phosphodiesterase-5 inhibitor sildenafil could improve the exercise capacity and pulmonary hemodynamics in patients with pulmonary arterial hypertension (PAH) on the basis of previous short-term studies. We tested this hypothesis in 14 subjects with PAH, including seven patients with the idiopathic form and seven patients with atrial septal defects, but no other congenital heart abnormalities. Patients were subjected to a 6-min walk test and dyspnea was graded according to the Borg scale. Pulmonary flow and pressures were measured by Doppler echocardiography. Patients were given sildenafil, 75 mg orally three times a day, and followed up for 1 year. Sildenafil therapy resulted in the following changes: increase in the 6-min walk distance from a median value of 387 m (range 0 to 484 m) to 462 m (range 408 to 588 m; P < 0.01), improvement of the Borg dyspnea score from 4.0 (median value) to 3.0 (P < 0.01), and increased pulmonary flow (velocity-time integral) from a median value of 0.12 (range 0.08 to 0.25) to 0.23 (range 0.11 to 0.40; P < 0.01) with no changes in pulmonary pressures. In one patient with pulmonary veno-occlusive disease diagnosed by a lung biopsy, sildenafil had a better effect on the pulmonary wedge pressure than inhaled nitric oxide (15 and 29 mmHg, respectively, acute test). He walked 112 m at baseline and 408 m at one year. One patient died at 11 months of treatment. No other relevant events occurred. Thus, chronic administration of sildenafil improves the physical capacity of PAH patients and may be beneficial in selected cases of veno-occlusive disease.
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PMID:One-year follow-up of the effects of sildenafil on pulmonary arterial hypertension and veno-occlusive disease. 1578 29

We report the use of oral sildenafil in a 5-month-old preterm infant with severe bronchopulmonary dysplasia and pulmonary arterial hypertension refractory to inhaled nitric oxide treatment, maximal ventilatory support and conventional vasodilator therapy. Sildenafil was prepared as a liquid suspension by the method of trituration and administered via an orogastric tube to the patient. Forty-eight hours after sildenafil treatment, echocardiography revealed that the tricuspid incompetence was substantially diminished and the contractility of both ventricles improved, indicating a marked reduction in pulmonary arterial pressure. Oral sildenafil treatment was continued for 6 months until complete resolution of pulmonary arterial hypertension, and oxygen supplement was weaned off. There was no adverse effect during the treatment period. Oral sildenafil may be useful in reducing pulmonary vascular resistance and can be considered for treatment of severe pulmonary arterial hypertension secondary to bronchopulmonary dysplasia.
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PMID:Oral sildenafil for treatment of severe pulmonary hypertension in an infant. 1587 Apr 96

Sildenafil and inhaled nitric oxide (iNO) relax smooth muscle by inhibiting the degradation and stimulating the production of cyclic guanosine monophosphate, respectively. We compared the acute pulmonary vasodilator effects of sildenafil, iNO, and epoprostenol and asked whether the combination of iNO with sildenafil had additive pulmonary vasodilator effects. We assessed the effects of extended use of sildenafil in a small cohort of patients. Twenty patients with pulmonary arterial hypertension underwent an acute vasodilator trial with sildenafil (all patients), iNO and iNO plus sildenafil (11), and epoprostenol (19). We also provided sildenafil to patients who were ineligible for, or had clinical deterioration on epoprostenol, treprostinil, or bosentan. Mean+/-se pulmonary artery pressure dropped by 13+/-3%, 19+/-4%, 14+/-3%, and 26+/-4% with epoprostenol, iNO, sildenafil, and iNO+sildenafil, respectively. Cardiac index increased with epoprostenol and sildenafil. A correlation was found between the effects of iNO and epoprostenol. Nine out of ten patients who were started on long-term sildenafil treatment alone or in combination with other vasodilators had symptomatic improvement. Three died of right heart failure. In conclusion, sildenafil is a potent acute pulmonary vasodilator, an effect that is potentiated by combination with iNO. Long-term therapy of pulmonary hypertension with sildenafil alone or in combination with other agents appears to be safe and well tolerated.
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PMID:Acute and chronic effects of sildenafil in patients with pulmonary arterial hypertension. 1732 34

More than 30 million men are estimated to have erectile dysfunction (ED) in the United States. Worldwide, ED is estimated to affect more than 150 million men, and that number is expected to exceed 300 million men by the year 2025. The prevalence of ED ranges from 7% in men aged 18-29 years to 85% in men aged 76-85 years. In addition, a recent report showed that 68% of patients with ED aged 18 years and older have at least one comorbid diagnosis of hypertension, hyperlipidaemia, diabetes or depression, and research suggests that ED may be an early indicator of systemic vascular disease. Viagra (sildenafil citrate), the first-in-class phosphodiesterase type 5 (PDE5) inhibitor, was introduced in 1998 for the treatment of ED. In the 7 years since its market launch, more than 750,000 physicians have prescribed sildenafil to more than 23 million men, helping establish an excellent safety and efficacy record. Clinical studies have demonstrated that sildenafil successfully treats ED of varied organic, psychogenic or mixed aetiology, and is effective in men with ED and comorbidities such as hypertension, hyperlipidaemia, diabetes or depression. Sildenafil was a breakthrough medication that addressed a previously unfulfilled medical need. The impact of sildenafil has stimulated academic, clinical and industrial research to better understand the nature of sexual function and develop better treatment and management for sexual dysfunctions such as ED. With the advent of other erectogenic therapies for the treatment of ED, this 7-year update will focus on the unique history and development of sildenafil, its current use and applications and its future directions and indications. Special emphasis is placed on the impact of sildenafil on our understanding of sexual health and on the extensive safety and efficacy data that have been amassed from numerous clinical trials.
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PMID:Past, present, and future: a 7-year update of Viagra (sildenafil citrate). 1592 97

The cyclic nucleotide signalling pathway mediates the smooth-muscle relaxing effects of nitric oxide necessary for normal erectile function. Down-regulation of this pathway is central to the pathophysiology of many forms of erectile dysfunction (ED), which is often associated with other chronic diseases (e.g. hypertension, type 2 diabetes mellitus) and treatments (e.g. certain drugs, radical prostatectomy). Conversely, selective inhibition of the enzyme that catalyses the degradation of cGMP (phosphodiesterase type 5, PDE-5) promotes erectile responses to sexual stimulation. The successful launch and commercialization of the selective PDE5 inhibitor (PDE5I) sildenafil transformed the treatment of ED, not only by providing an effective, well tolerated oral ED therapy, but also by fostering greater candour about the problem among men. Sildenafil is highly effective in promoting erectile responses across a wide spectrum of severity and causes of ED, including patients with ED that is often refractory to treatment. The recent advent of vardenafil, which has the highest in vitro potency of all available PDE5Is, and tadalafil, which has a prolonged half-life that may enable couples to have sexual activity with less planning, represent further advances. Other PDE5Is offering further potential improvements are under active investigation.
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PMID:Phosphodiesterase type 5 inhibitors for erectile dysfunction. 1604 13

New approaches to the treatment of pulmonary arterial hypertension (PH) have increased symptomatic relief and prolonged survival. PH is a common sequela of the hemoglobinopathies, but the use of standard oral treatment options is limited because of toxicity and poor effectiveness. Sildenafil citrate is a selective and potent inhibitor of cGMP-specific phosphodiesterase-5 (PDE5), which promotes selective smooth muscle relaxation in lung vasculature and has been used successfully in the treatment of PH. Hemoglobinopathic patients suffering from severe PH who were treated with sildenafil citrate (50 mg b.i.d.) for periods ranging from 4 to 48 months showed a significant decrease in pulmonary pressure and improvement in exercise capacity and functional class. No significant adverse events were reported. These data, described in a small group of patients, indicate that sildenafil citrate is effective in the treatment of PH in hemoglobinopathies and is well tolerated long-term at a daily dose of 100 mg.
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PMID:Therapeutic approaches to pulmonary hypertension in hemoglobinopathies: Efficacy and safety of sildenafil in the treatment of severe pulmonary hypertension in patients with hemoglobinopathy. 1633

Sildenafil has been shown to be an effective treatment of pulmonary arterial hypertension and is believed to present with pulmonary selectivity. This study was designed to determine the site of action of sildenafil compared with inhaled nitric oxide (NO) and intravenous sodium nitroprusside (SNP), known as selective and nonselective pulmonary vasodilators, respectively. Inhaled NO (40 ppm), and maximum tolerated doses of intravenous SNP and sildenafil, (5 microg x kg(-1) x min(-1) and 0.1 mg x kg(-1) x h(-1)), respectively, were administered to eight dogs ventilated in hypoxia. Pulmonary vascular resistance (PVR) was evaluated by pulmonary arterial pressure (Ppa) minus left atrial pressure (Pla) vs. flow curves, and partitioned into arterial and venous segments by the occlusion method. Right ventricular hydraulic load was defined by pulmonary arterial characteristic impedance (Zc) and elastance (Ea) calculations. Right ventricular arterial coupling was estimated by the ratio of end-systolic elastance (Ees) to Ea. Decreasing the inspired oxygen fraction from 0.4 to 0.1 increased Ppa - Pla at a standardized flow of 3 l x min(-1) x m(-2) from 6 +/- 1 to 18 +/- 1 mmHg (mean +/- SE). Ppa - Pla was decreased to 9 +/- 1 by inhaled NO, 14 +/- 1 by SNP, and 14 +/- 1 mmHg by sildenafil. The partition of PVR, Zc, Ea, and Ees/Ea was not affected by the three interventions. Inhaled NO did not affect systemic arterial pressure, which was similarly decreased by sildenafil and SNP, from 115 +/- 4 to 101 +/- 4 and 98 +/- 5 mmHg, respectively. We conclude that inhaled NO inhibits hypoxic pulmonary vasoconstriction more effectively than sildenafil or SNP, and sildenafil shows no more selectivity for the pulmonary circulation than SNP.
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PMID:Effects of sildenafil on hypoxic pulmonary vascular function in dogs. 1677 5

Many of the physiological responses to nitric oxide (NO) are mediated by cyclic 5'-guanosine monophosphate (cGMP), the intracellular levels of which are regulated by phosphodiesterase type 5 (PDE5). In situations of reduced NO formation, the inhibition of PDE5 by selective inhibitors such as sildenafil could be beneficial in restoring physiological functions by enhancing the intracellular levels of cGMP. In this study, we evaluated the effects of sildenafil on the hemodynamic and histological alterations induced by the chronic treatment of rats with N(omega)-nitro-L-arginine-methyl ester (L-NAME). After 8 weeks of concomitant treatment with sildenafil and L-NAME, arterial blood pressure was significantly lower (P<0.05) than in L-NAME-treated rats. The fall in blood pressure was associated with a slight reduction in the total peripheral vascular resistance (P<0.05). Sildenafil partially prevented the decrease in cardiac output seen in L-NAME-treated rats. Morphologically, sildenafil reduced the total area of the myocardial lesions and attenuated the cardiomyocyte and vascular smooth muscle remodeling seen with L-NAME. These results show that sildenafil prevented the deleterious hemodynamic and morphological alterations associated with L-NAME-induced hypertension. This beneficial effect was probably mediated by an increase in cardiac and vascular cGMP levels as reflected in circulating plasma cGMP levels.
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PMID:Sildenafil reduces cardiovascular remodeling associated with hypertensive cardiomyopathy in NOS inhibitor-treated rats. 1680 60

Pulmonary arterial hypertension is a life-threatening, rare disease characterised by vasoconstriction and vascular remodelling of pulmonary artery vessels. Pulmonary arterial hypertension can occur without an obvious cause or can be secondary. Until several years ago, therapeutic approaches were represented mainly by 'conventional therapy' (anticoagulants, calcium channel blockers, diuretics and digoxin, and oxygen therapy). But recently 'specific therapies' (i.e., therapies targeting specific pathogenic pathways) have become available; these are therapies represented by prostacyclin and its derivatives, endothelin receptor antagonists or phosphodiesterase-5 inhibitors. Sildenafil citrate is a phosphodiesterase-5 inhibitor and is the second oral pharmacological agent recently approved for the treatment of pulmonary arterial hypertension. Sildenafil has demonstrated short- and long-term clinical efficacy in the treatment of various forms of pulmonary arterial hypertension, either alone or in combination with other agents, but its safety profile needs further assessment.
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PMID:Sildenafil for pulmonary arterial hypertension: when blue turns into white. 1692 6

There are no published controlled clinical trials of regular phosphodiesterase type 5 inhibitor therapy as a long-term treatment of hypertension. In a randomized, double-blind, 2-way crossover study, 25 otherwise untreated hypertensive subjects were administered 50 mg of sildenafil or matched placebo 3 times daily for 16 days, and the effects on ambulatory blood pressure (BP), clinic BP, arterial wave reflection, carotid-femoral pulse wave velocity, and brachial artery flow-mediated dilatation were assessed. Three subjects were withdrawn because of adverse effects, and the data from the remaining 22 subjects were analyzed. Sildenafil reduced ambulatory BP (mean [SE] change from baseline for average daytime BP: systolic -8 [2] mm Hg versus 2 [2] mm Hg with placebo, P<0.01; diastolic -6 [1] mm Hg versus 0 [1] mm Hg, P<0.01) and clinic BP (change from baseline to 1 hour after drug administration on day 16: systolic -5 [2] mm Hg versus 4 [2] mm Hg, P<0.01; diastolic -5 [1] mm Hg versus 2 [2] mm Hg, P<0.01). Compared with baseline, sildenafil, but not placebo, reduced arterial wave reflection both acutely and after chronic treatment, but the chronic change in arterial wave reflection was not statistically different from the chronic change with placebo. Sildenafil did not affect pulse wave velocity or flow-mediated dilatation. The main adverse effects of sildenafil, which were generally transient and rated as mild or moderate in severity, were dyspepsia, headache, and myalgia. In conclusion, regular sildenafil constitutes effective antihypertensive therapy. Further studies are warranted to evaluate the role of longer-acting phosphodiesterase type 5 inhibitors as antihypertensive agents in clinical practice.
Hypertension 2006 Oct
PMID:Effect of regular phosphodiesterase type 5 inhibition in hypertension. 1744 22


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