Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

The highly putrefied corpse of an 80-year-old man was found in the apartment which he had rented to a prostitute. A package of Viagra 25 was found beside the corpse and three tablets were missing. Autopsy revealed severe coronary artery sclerosis as well as signs of previous myocardial infarctions. For the detection and identification of sildenafil and three metabolites in urine and tissue samples, solid-phase extraction, LC/MS and MS/MS methods were developed. Blood was not available for toxicological analysis due to the putrefaction. For method development, urine from a volunteer who had ingested 25 mg sildenafil was collected over 8 h, and three metabolites were identified by MS/MS. These metabolites were also found in the victim's urine. These findings prove that sildenafil was taken some time prior to death, but the causality of sildenafil intake and fatal cardiac failure could not be proven, since no blood was available for analysis. However, the administration of sildenafil was contraindicated due to several previous myocardial infarctions.
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PMID:Post-mortem detection and identification of sildenafil (Viagra) and its metabolites by LC/MS and LC/MS/MS. 1135 5

Erectile dysfunction (ED) in men is amenable to correction with Viagra in a majority of patients. The accumulated experience of prescribing Viagra across the broad continuum of men suffering from ED is sufficient for a meaningful assessment of the safety of Viagra in clinical practice. The use of Viagra necessitates caution in cardiac failure and when used within six months of acute myocardial infarction and stroke. It is inadvisable in patients with unstable angina pectoris. The co-administration of Viagra with organic nitrates, for example, glyceryl trinitrate or isosorbide dinitrate, is unsafe. The relative contraindications to Viagra in cardiovascular disease are uncontrolled hypertension and impaired cardiac reserve. With respect to interactions with other drugs, the potential influence on the metabolism of Viagra by medications that affect the cytochrome-P-450 system does not translate into clinical effects. The vasodilatory properties of sildenafil citrate are largely responsible for unwanted effects. The most common side effects are headache, flushing (due to vasodilation), and dyspepsia (due to relaxation of the smooth muscle of the gastroesophageal sphincter with reflux). In the recommended single-dose range (25-100 mg), the use of Viagra for erectile dysfunction, in the absence of contraindications, is extremely safe provided the drug is taken under proper conditions.
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PMID:The clinical safety of viagra. 1207 89

Sildenafil citrate is the first oral phosphodiesterase type 5 inhibitor approved for the treatment of erectile dysfunction. The wide use of sildenafil by patients with erectile dysfunction and cardiovascular disease has resulted in a considerable number of independent studies investigating the cardiovascular safety and functional role of the phosphodiesterase type 5-cyclic guanosine monophosphate-nitric oxide pathway in the cardiovascular system. Endothelial dysfunction, defined as a reduction in the bioavailability of nitric oxide, is associated with many of the common risk factors for cardiovascular disease and erectile dysfunction. Sildenafil has been demonstrated to improve the vasomotor aspect of endothelial dysfunction in patients with heart failure and diabetes. Hemodynamic studies suggest that sildenafil is a modest vasodilator with the potential to increase coronary blood flow and coronary flow reserve. In patients with ischemic heart disease, sildenafil is associated with reductions in mean arterial and pulmonary pressure with little effect on heart rate, cardiac output, and systemic or pulmonary vascular resistance. The absence of an effect on cardiac output supports the lack of an inotropic effect of sildenafil. This is consistent with the finding that sildenafil has no effect on cyclic adenosine monophosphate levels in the vasculature. Finally, exciting reports have emerged from clinical experience with the use of phosphodiesterase type 5 inhibitors in patients with pulmonary hypertension.
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PMID:Coronary and systemic hemodynamic effects of sildenafil citrate: from basic science to clinical studies in patients with cardiovascular disease. 1241 49

Phosphodiesterases (PDEs) are a superfamily of enzymes that degrade the intracellular second messengers cyclic AMP and cyclic GMP. As essential regulators of cyclic nucleotide signalling with diverse physiological functions, PDEs are drug targets for the treatment of various diseases, including heart failure, depression, asthma, inflammation and erectile dysfunction. Of the 12 PDE gene families, cGMP-specific PDE5 carries out the principal cGMP-hydrolysing activity in human corpus cavernosum tissue. It is well known as the target of sildenafil citrate (Viagra) and other similar drugs for the treatment of erectile dysfunction. Despite the pressing need to develop selective PDE inhibitors as therapeutic drugs, only the cAMP-specific PDE4 structures are currently available. Here we present the three-dimensional structures of the catalytic domain (residues 537-860) of human PDE5 complexed with the three drug molecules sildenafil, tadalafil (Cialis) and vardenafil (Levitra). These structures will provide opportunities to design potent and selective PDE inhibitors with improved pharmacological profiles.
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PMID:Structure of the catalytic domain of human phosphodiesterase 5 with bound drug molecules. 1295 49

This study reports results of the detection and quantitation of sildenafil (Viagra) in biological fluids and tissues and its stability in fixed tissues and formalin solutions in which the tissues were fixed. Toxicological analyses were performed on samples from a 60-year-old man who died of acute heart failure due to myocardiosclerosis. Sildenafil pills were found in his pocket. At the time of autopsy, sildenafil was found in body fluids and tissues (blood 0.04 mg/L, bile 0.99 mg/L, gastric contents 6.84 mg/L, urine 9.60 mg/L, brain 6.43 mg/kg, heart 6.10 mg/kg, kidney 4.28 mg/kg, liver 5.46 mg/kg, lung 5.38 mg/kg, spleen 1.38 mg/kg). Tissue samples were preserved in formalin solutions for four weeks. Analyses of formalin-fixed tissues and formalin solutions in which the same tissues had been preserved allowed the detection and quantitation of sildenafil (brain 2.20 mg/kg, formalin from brain 4.01 mg/L; heart 1.46 mg/kg, formalin from heart 4.41 mg/L; kidney 0.98 mg/kg, formalin from kidney 3.19 mg/L; liver 2.19 mg/kg, formalin from liver 3.21 mg/L; lung 1.02 mg/kg, formalin from lung 4.18 mg/L; spleen 0.28 mg/kg, formalin from spleen 0.94 mg/L). Results indicate that sildenafil has good stability in biological specimens subjected to chemical fixation.
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PMID:Postmortem distribution of sildenafil in histological material. 1687 74

Heart failure is a condition that affects nearly 5 million people in the United States and costs the nation an estimated $35 billion a year. Although common, the condition presents treating clinicians with real challenges. There currently are few effective therapies for people with acute decompensated disease. As part of the National Heart Lung and Blood Institute-funded Heart Failure Network, Minnesota researchers are attempting to change this. This article describes the work of the Heart Failure Network and several Minnesota-designed protocols that are being tested, including one that's looking at 2 different treatment strategies for patients hospitalized with acute decompensated heart failure who go on to develop poor renal function and another that will evaluate the use of sildenafil (Viagra) for patients with heart failure and preserved left ventricular systolic function.
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PMID:Advances in heart failure: Minnesota's role in the NHLBI's Heart Failure Network. 1826 68

To date, studies suggest that biological signaling by nitric oxide (NO) is primarily mediated by cGMP, which is synthesized by NO-activated guanylyl cyclases and broken down by cyclic nucleotide phosphodiesterases (PDEs). Effects of cGMP occur through three main groups of cellular targets: cGMP-dependent protein kinases (PKGs), cGMP-gated cation channels, and PDEs. cGMP binding activates PKG, which phosphorylates serines and threonines on many cellular proteins, frequently resulting in changes in activity or function, subcellular localization, or regulatory features. The proteins that are so modified by PKG commonly regulate calcium homeostasis, calcium sensitivity of cellular proteins, platelet activation and adhesion, smooth muscle contraction, cardiac function, gene expression, feedback of the NO-signaling pathway, and other processes. Current therapies that have successfully targeted the NO-signaling pathway include nitrovasodilators (nitroglycerin), PDE5 inhibitors [sildenafil (Viagra and Revatio), vardenafil (Levitra), and tadalafil (Cialis and Adcirca)] for treatment of a number of vascular diseases including angina pectoris, erectile dysfunction, and pulmonary hypertension; the PDE3 inhibitors [cilostazol (Pletal) and milrinone (Primacor)] are used for treatment of intermittent claudication and acute heart failure, respectively. Potential for use of these medications in the treatment of other maladies continues to emerge.
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PMID:cGMP-dependent protein kinases and cGMP phosphodiesterases in nitric oxide and cGMP action. 2071 71

Sildenafil (Viagra) is the most effective oral therapy currently available for erectile dysfunction. Patients should be given clear instructions regarding the use of sildenafil. The most common side effects include flushing, headaches, dyspepsia, and transient visual changes. In combination with nitrates, it can and has caused fatal hypotension. It should not be prescribed to patients on nitrates. Additionally, nitrates should not be administered to anyone who has recently ingested sildenafil. Synergetic blood pressure lowering has not been observed when sildenafil was used with other classes of antihypertensives. Sildenafil is not offered to patients with low cardiac output states, those on intensive regimens to prevent heart failure or those with acute coronary ischemia.
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PMID:Sildenafil (viagra) and the heart. 2300 45