Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sildenafil citrate, an oral therapy for erectile dysfunction, is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), the predominant isozyme metabolizing cGMP in the corpus cavernosum. Chemically, it is a compound of the pyrazolo-pyrimidinyl-methylpiperazine class. Sildenafil has no direct relaxant effect on human corpus cavernosum but enhances the relaxant effect of nitric oxide (NO) on the corpus cavernosum by inhibiting PDE5, which is responsible for degradation of cGMP in this tissue. When sexual stimulation causes local release of NO, inhibition of PDE5 by sildenafil increases concentrations of cGMP in the corpus cavernosum, causing smooth muscle relaxation and blood flow into the penis, resulting in an erection. Sildenafil at recommended doses has no effect in the absence of sexual stimulation. The drug is rapidly absorbed after oral administration, with absolute bioavailability of 40%. Its pharmacokinetics are dose proportional over the recommended dosage range. Maximum plasma concentrations are reached within 30 to 120 minutes after oral dosing in the fasting state. Sildenafil is cleared predominantly by the hepatic microsomal isoenzymes CYP3A4 (major route) and CYP2C9 (minor route). Clinical studies assessed the effect of sildenafil on the ability of men with erectile dysfunction to engage in sexual activity and, specifically, to achieve and maintain an erection sufficient for satisfactory sexual intercourse. Sildenafil was evaluated at doses of 25, 50, and 100 mg in randomized, double-masked, placebo-controlled clinical trials of up to 6 months' duration. The drug was administered to hundreds of patients aged 19 to 87 years having erectile dysfunction of various etiologies for a mean duration of 5 years. Sildenafil was associated with statistically significant improvement in erectile function compared with placebo. Adverse effects reported at a rate of >2% were headache, flushing, dyspepsia, nasal congestion, urinary tract infection, abnormal vision, diarrhea, dizziness, and rash. No cases of priapism were reported. The use of sildenafil is contraindicated in men who are taking organic nitrates, because of the potential for a precipitous decrease in blood pressure. Postmarketing reports and surveillance have revealed at least 39 deaths with sildenafil use in men having a history of heart disease, men taking nitrate medications, and men in poor physical health due to lack of exercise. Many of the men who experienced serious adverse effects or death had a variety of concomitant diseases and were taking multiple medications.
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PMID:Safety and efficacy of sildenafil citrate in the treatment of male erectile dysfunction. 991 1

BACKGROUND: The introduction of the drug sildenafil (Viagra; Pfizer, New York, NY) into the armamentarium for treatment of erectile dysfunction is a major advance. Many of the patients who will benefit from its use have cardiovascular disease. Erectile dysfunction and cardiovascular disease share common risk factors. Although the metabolic demands of sexual activity are modest and the associated risk for coronary events is low, the clinician caring for cardiac patients needs to be aware of the pharmacology and hemodynamic profile of sildenafil in those with heart disease who use cardioactive drugs. METHODS AND RESULTS: We reviewed the current literature relating to the pharmacology, hemodynamic profile, efficacy, safety, and clinical application of sildenafil in patients with cardiovascular disease. Sildenafil is highly effective in the treatment of erectile dysfunction. The overall incidence of cardiovascular adverse events is low and similar to placebo. Current postmarketing data do not suggest an increase in cardiovascular death in sildenafil users. The drug is contraindicated in those taking organic nitrates. It should be used with caution and on an individual basis in patients who have active coronary ischemia and heart failure with tenous blood pressure and volume status. CONCLUSIONS: When used with discretion, sildenafil is safe, effective, and has the potential to greatly enhance quality of life in the relatively large proportion of the population with heart disease.
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PMID:Viagra and Cardiovascular Disease. 1068 47

Sildenafil has been registered for the treatment of erectile dysfunction since 1998. World wide a large number of patients were reported, dying of acute heart disease after using sildenafil. Therefore the patient instruction text was adapted. Simultaneous use of sildenafil and nitrates is contraindicated because of serious decrease of the blood pressure. The use of sildenafil can lead to physical stress in patients with a history of heart disease and a treadmill test assessment is advisable. In two years 38 adverse reactions were seen in 25 Dutch patients. The Dutch reports (three cardiovascular deaths since the introduction) also show the dilemmas in the assessment of the safety of sildenafil: is it the underlying disease or is it the drug that causes death? Further research into the adverse reactions has to be done, therefore reporting suspected side effects of sildenafil is important.
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PMID:[Side effects of sildenafil: findings from two years practical experience]. 1128 86

Erectile dysfunction (ED) and depression are highly prevalent conditions and frequently occur concomitantly in predisposed individuals. Men with ED and depression are also likely to have other comorbid conditions, including diabetes, hypertension, and heart disease. Because ED is also a common adverse effect of some medications for these conditions, patients are frequently noncompliant with treatment. Sildenafil citrate (Viagra) is effective in treating ED of a broad range of etiologies, suggesting that it may be equally beneficial in patients with ED that is associated with depressive symptoms and in those with ED resulting from serotonergic reuptake inhibitor (SRI) antidepressant treatment. We review the results of 3 randomized, placebo-controlled trials and a retrospective analysis of data pooled from 10 clinical trials that examine the efficacy of sildenafil in treating ED associated with depression and as an adverse effect of SRI treatment. The results suggest that sildenafil is efficacious as a first-line treatment for ED in men with untreated minor depression, in men with ED that is refractory to successful SRI treatment of depression, and in those whose depression was successfully treated but who developed ED as a consequence of SRI treatment. Given the complex interrelations among ED, depression, and other comorbid conditions, the key to proper management is a comprehensive evaluation, including sexual function, and an accurate differential diagnosis.
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PMID:Depression, antidepressant therapies, and erectile dysfunction: clinical trials of sildenafil citrate (Viagra) in treated and untreated patients with depression. 1241 34

In Germany, some 4-6 million men, including 1.2 million diabetics, suffer from erectile dysfunction (ED). Various other diseases including heart disease, hypertension, arteriosclerosis, hyperlipidemia, endocrine disorders, chronic renal insufficiency, prior radical prostatectomy, neurological diseases, trauma and the abuse of alcohol, tobacco, and side effects of medications, are frequently associated with ED. Medical history, clinical examination, routine blood chemistry and sexual hormone levels may help clarify the etiology of ED. Normally, relaxation of the smooth muscles of the corpus cavernosum--mediated by cGMP and cAMP--together with dilatation of penile arteries and occlusion of venous outflow, results in an erection. The oral type V phosphodiesterase inhibitor, Sildenafil, or prostaglandin E1 injection elevates the cGMP and cAMP levels, respectively. Other therapeutic options include mechanical aids, surgery, hormone replacement or sublingual apomorphine. Since 1998, Sildenafil, an effective, simple and safe oral treatment, has been available.
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PMID:[Erectile dysfunction. An important manifestation of autonomic diabetic neuropathy]. 1253 21

Pulmonary hypertension is characterised by a progressive increase in pulmonary vascular resistance and a poor prognosis. The exact underlying mechanisms are still poorly understood; however, it is hypothesised that pulmonary medial hypertrophy and endothelial dysfunction lead to impaired production of vasodilators such as nitric oxide (NO) and prostacyclin, and increased expression of vasoconstrictors such as endothelin-1. The current treatment modalities for pulmonary hypertension include conventional supportive therapies and more specific pharmacological therapies that are targeted at abnormalities of endothelial function. NO and phosphodiesterase type 5 (PDE5) inhibitors induce pulmonary vasodilation by increasing intracellular cyclic guanosine monophosphate (cGMP) concentrations. Sildenafil citrate is a highly selective inhibitor of PDE5. Investigations in animal models and recent clinical case reports with some studies in the paediatric population suggest that sildenafil may be a promising agent in treating pulmonary hypertension. The effect of sildenafil on pulmonary vasculature appears to be independent of the underlying cause, thereby providing a role in idiopathic pulmonary arterial hypertension (PAH), PAH associated with congenital heart disease, pulmonary hypertension secondary to lung disease or persistent pulmonary hypertension of the newborn. It may also be beneficial in postoperative pulmonary hypertension and in neonates who are difficult to wean from inhaled NO. It is easily administered and effective, and has minimal systemic adverse effects. Although the reported results in children with pulmonary hypertension are promising, it is an experimental drug and large-scale randomised controlled studies are required to validate the safety, efficacy and dosage in the paediatric population.
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PMID:Therapeutic applications of sildenafil citrate in the management of paediatric pulmonary hypertension. 1720 64

Erectile dysfunction (ED) is a highly prevalent disease associated with aging as well as with several risk factors including hypertension, heart disease, obesity, dyslipidemia, diabetes, hypogonadism, drugs-related, and pelvic surgery. Many of these factors are components of the metabolic syndrome, a multiplex risk factor for cardiovascular disease (CVD). ED shares common risk factors with CVD. Endothelial dysfunction seems to be the early underlying pathophysiology across both conditions. The efficacy, tolerability and cardiovascular safety of sildenafil has been evaluated in numerous large, randomized, doubleblind, placebo-controlled clinical studies in the broad population of men with ED including men with several co-morbid conditions. Sildenafil is effective in several specific patient populations including the difficult-to-treat subpopulations such as diabetes mellitus and after radical prostatectomy. It is associated with rapid onset of action--within 14 minutes for some men--and an extended duration of action for up to 12 hours. Sildenafil improves quality of life and satisfaction for treated men and is well tolerated with a favorable safety profile. New data suggest that sildenafil has beneficial effects in several chronic conditions. It has been approved for the treatment of idiopathic pulmonary hypertension. Numerous articles have suggested that it improves endothelial function and a possible role on premature ejaculation or treatment of lower urinary tract symptoms has been suggested.
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PMID:Sildenafil in the treatment of erectile dysfunction: an overview of the clinical evidence. 1804 17

Sildenafil is a phosphodiesterase 5 inhibitor widely used for the treatment of pulmonary hypertension in children. Despite limited available safety and efficacy evidence, use of sildenafil continues to increase. To date, sildenafil use for pediatric pulmonary hypertension has been characterized for 193 children through 16 studies and 28 case series and reports. The primary efficacy data suggest that sildenafil is beneficial for facilitating the weaning of inhaled nitric oxide in children after cardiac surgery. Compiled safety data suggest that sildenafil is well tolerated among children with idiopathic pulmonary arterial hypertension and pulmonary arterial hypertension associated with congenital heart disease. This review summarizes the available data describing the use, safety, and efficacy of sildenafil for children with pulmonary hypertension.
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PMID:Sildenafil for the treatment of pulmonary hypertension in pediatric patients. 1970 81

Patients with Eisenmenger syndrome form a small percentage of congenital heart disease patients. The rarity of this syndrome, combined with its complex pathophysiology, account for the insufficient understanding of the principles underlying its proper treatment. The main clinical symptoms are: cyanosis due to secondary erythrocytosis, resulting in increased blood viscosity, iron deficiency anemia (enhanced by unnecessary phlebotomies), blood clotting disturbances, heart failure and serious supraventricular and ventricular arrhythmias. Recent decades have seen developments in pulmonary hypertension pathophysiology which have led to the introduction of new groups of drugs: prostacycline analogs (Epoprostenol, Treprostinil, Beraprost, Illoprost), phosphodiesterase inhibitors (Sildenafil, Tadalafil), endothelin receptor antagonists (Bosentan, Sitaxantan, Ambrisentan) and nitric oxide. These drugs should be administered to patients in III-IV NYHA class. Despite successful early results, the therapeutic effect on patients with Eisenmenger syndrome has not been conclusively established. Our therapeutic efforts should be directed mainly towards preventing complications. As a rule, we should avoid agents with no established therapeutic efficacy and try to alleviate symptoms without any additional risk, so as not to disrupt the existing clinical balance.
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PMID:Therapeutic methods used in patients with Eisenmenger syndrome. 1995 85

Common complications after surgery for transposition of the great arteries (TGA) include systemic ventricular dysfunction and arrhythmia after atrial baffle repair (AB) and outflow tract stenosis or regurgitation after the arterial switch (AS). Severe pulmonary hypertension (PHT) is a rarely reported problem after AB and AS. In this study we sought to evaluate the frequency of late onset severe PHT following surgical repair for TGA. We report 3 cases, 2 after AB and 1 after AS, describe the frequency of this complication and treatment response, by comparing the response to pulmonary vasodilators in this group of patients to that of idiopathic or connective tissue disease (CTD) related PHT. We currently follow 85 patients >or=17 years of age with repaired TGA; 77 after AB and 8 after AS. 3.5% of our adult congenital heart disease patients with TGA have developed late severe PHT. None of these patients demonstrated clinical improvement with Bosentan at 6 months, however 2 of 3 were stabilised with the addition of Sildenafil to initial therapy. The third patient died 4 months after the diagnosis of severe PHT, whilst waiting for heart-lung transplantation, despite Bosentan, Sildenafil and inotropic support. By contrast, of 37 patients with idiopathic or CTD related PHT commenced on Bosentan as initial therapy, 32 (86.5%) demonstrated a clinical response at 6 months; the other patients had Sildenafil as added therapy after 6 months. Our data suggest that patients with TGA and late onset PHT are less likely to achieve a clinical response on pulmonary vasodilator monotherapy (P = 0.006). Whilst more investigation is needed, our experience suggests an aggressive clinical course, often requiring combination PHT treatment.
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PMID:Late-onset pulmonary arterial hypertension after a successful atrial or arterial switch procedure for transposition of the great arteries. 1999 25


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