Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Primary pulmonary arterial hypertension (PPH) is a rare disease of undetermined origin and fatal prognosis. A better prognosis is associated with at least 20% reduction of either pulmonary artery pressure or pulmonary vascular resistance ("responders") in acute vasodilatory trials. Prostacycline (PGI2) or nitric oxide (NO) administration promises valuable results. NO is one of the most powerful vasodilating agents, endogenously produced by endothelial cells. It migrates from these cells to smooth muscle cells and stimulates production of cGMP, that induces smooth muscle relaxation. cGMP is hydrolyzed by 5-phopshodiesterase (PDE-5). Several papers documenting hypotensive effect in pulmonary circulation of specific PDE5 inhibitor--sildenafil (Viagra--Pfizer) have been published recently. We present a case report of a 26 year old female patient with PPH--"nonresponder" in a trial with NO--and NO responder after sildenafil administration. Initial values were: mean pulmonary artery pressure (mPAP) was 58 mmHg, pulmonary vascular resistance was 10.9 Wood's units. mPAP and PVR during NO inhalation (40 ppm) decrease from 62 to 54 mmHg and from 11.4 to 10.3 Wood's units, respectively. Measurements performed 60 minutes after 50 mg of sildenafil orally disclosed a 19% reduction of mPAP and 21% reduction of PVR. NO inhalation caused further decrease of both parameters: mPAP was decreased for additional 28% and PVR for additional 36% in comparison to initial results. Neither peripheral hypotension nor other side effects were observed. A month-long administration of sildenafil in a dose 2 x 25 mg daily reduced mPAP and PVR to values reported for the acute trial. Physical capability improved also. It was assessed as increased distance in a six-minute-walk test (280 vs. 400 m in the first week of treatment, and 330 m in a fourth week of treatment). Echocardiography showed moderate decrease of right ventricle and right atrium diameters, along with decrease of the degree of relative tricuspid regurgitation with unchanged maximal velocity of regurgitant wave. Specific PDE-5 inhibitors might be an attractive alternative in the treatment of pulmonary hypertension in case the above noted observations are confirmed.
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PMID:[Sildenafil reduces pressure and pulmonary resistance and increases susceptibility of pulmonary arteries to nitric oxide in primary pulmonary arterial hypertension]. 1609 62

Systolic pulmonary arterial hypertension (PAH) was diagnosed in a 15-year-old intact male Yorkshire terrier presented for progressive dyspnoea and coughing. Several examinations were performed (thoracic radiographs, faecal analysis, heartworm antigen test, tracheal fluoroscopy, abdominal ultrasound, complete blood cell count, urine and serum biochemistry) but the PAH remained of unknown origin. Despite medical treatment (diuretics and angiotensin-converting enzyme inhibitor), cardiovascular and respiratory signs dramatically worsened over a 1-month period, with several daily syncope, cyanosis and tachypnoea at rest requiring permanent oxygen therapy. Oral tadalafil (Cialis), a new long-acting phosphodiesterase-5 inhibitor, belonging to the same family as sildenafil (Viagra), was added to the background therapy. The condition of the dog improved quickly (< 24 h), and short-term follow up (7 days) showed a decrease in systolic pulmonary arterial pressure up to 26 mmHg concomitant with the disappearance of all respiratory and cardiac signs of PAH (cyanosis, syncope and tachypnoea). This case is of interest because it concerns the first reported short-term use of tadalafil in canine PAH. However, long-term studies with a large number of diseased animals are now required before prescription by general practitioners could be recommended.
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PMID:Efficacy of oral tadalafil, a new long-acting phosphodiesterase-5 inhibitor, for the short-term treatment of pulmonary arterial hypertension in a dog. 1653 28

Sildenafil citrate (Viagra; Pfizer Inc, New York, NY) relaxes vascular smooth muscle, resulting in modest reductions in blood pressure that are insufficient to stimulate a reflex increase in heart rate. These blood pressure reductions are similar for healthy men and men with coronary artery disease (CAD) or who use antihypertensive drugs. Sildenafil does not affect the force of cardiac contraction, and cardiac performance is unaffected. Sildenafil is mildly vasodilating in the coronary circulation and does not increase the risk of ventricular arrhythmia. During exercise and recovery, sildenafil does not cause clinically significant alterations in hemodynamic parameters in men with CAD, and it has no negative effects on coronary oxygen consumption, ischemia, or exercise capacity. Clinical trial data from >13,000 patients, 7 years of international postmarketing data, and observational studies of >28,000 men in the United Kingdom and 3813 men in the European Union reveal that (1) there are no special cardiovascular concerns when sildenafil is used in accordance with product labeling and (2) the risk for serious events such as myocardial infarction or death is not increased. However, because safety has not been established in patients with recent serious cardiovascular events, hypotension or uncontrolled hypertension, or retinitis pigmentosa, physicians should consult their current local prescribing information before prescribing sildenafil for these patients. Among men with erectile dysfunction treated with sildenafil, the adverse event profile is similar overall to that in men with comorbid cardiovascular disease (CVD), it is similar between those with and without CAD, and it is similar between those who take and those who do not take antihypertensive drugs (regardless of the number or class). In a controlled interaction study of sildenafil and amlodipine, the mean additional reduction in supine blood pressure was 8 mm Hg systolic and 7 mm Hg diastolic. Sildenafil should be used with caution in patients who take alpha-blockers because coadministration may lead to symptomatic hypotension in some individuals. When sildenafil is coadministered with an alpha-blocker, patients should be stable on alpha-blocker therapy before initiating sildenafil treatment and sildenafil should be initiated at the lowest dose. Also, in the absence of information specific to mixed alpha/beta blockers, such as carvedilol and labetalol, similar care should be taken as for alpha-blockers. Sildenafil potentiates the hypotensive effects of nitrates, and its administration to patients who are using organic nitrates in any form, either regularly or intermittently, is contraindicated. Before prescribing sildenafil, physicians should carefully consider whether their patients with underlying CVD could be affected adversely by resuming sexual activity. Management recommendations based on cardiovascular risk, from the Second Princeton Consensus Conference, are presented.
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PMID:Cardiovascular safety of sildenafil citrate (Viagra): an updated perspective. 1701 75

Although sildenafil (Viagra) and other phosphodiesterase V (PDE V) inhibitors are increasingly recognized for their use in the treatment of male erectile dysfunction and perhaps more recently pulmonary artery hypertension, less is known of their potential beneficial effects in other situations. Medeiros et al., in the current issue of the British Journal of Pharmacology, report that sildenafil dramatically reduces alcohol-induced gastric damage in rats. The authors provide convincing evidence that such protection not only occurs via the nitric oxide (NO)/cGMP pathway, but also involves regulation of ATP-sensitive potassium channels. Therefore, in addition to exerting anti-impotence efficacy, PDE V inhibitors may provide significant beneficial effects from mucosal injury induced by alcohol.
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PMID:Sildenafil reduces alcohol-induced gastric damage: just say 'NO'. 1807

Phosphodiesterase (PDE) isoenzymes hold a central role in controlling levels of the cyclic nucleotide monophosphates cyclic AMP and cyclic GMP, which are important second messengers in many transmitter pathways involved in regulating biological processes in urogenital tissues. The development of the PDE5 inhibitors Sildenafil (Viagra), Vardenafil (Levitra), and Tadalafil (Cialis), combining a high response rate and the advantage of on-demand intake, is the result of the scientific characterization of the physiology of penile erectile smooth muscle.The introduction of these compounds as safe and well-tolerated orally active drugs for the treatment of erectile dysfunction has not only become a worldwide clinical success, but it provided the basis for the development and introduction of several new therapeutic modalities into the management of male and female sexual dysfunction. It has also brought further attention to cyclic nucleotide phosphodiesterases as putative pharmacological targets in a variety of disorders, such as pulmonary arterial hypertension, Raynaud's disease, Peyronie's disease, the so-called benign prostatic syndrome, endothelial dysfunction, disturbances of male ejaculatory function (premature ejaculation), and female sexual dysfunction.Because the concept of taking a pill to cure an illness or relieve disease symptoms has become widely accepted by consumers, pharmacological research and development is focusing primarily on selective orally available drugs that influence peripheral intracellular or central regulatory mechanisms. This review briefly describes the current and evolving advances in the field of PDE5 pharmacotherapy in urology and other fields of medicine.
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PMID:[The basics of phosphodiesterase type 5 (PDE5) inhibition in urology]. 1885 69

Sildenafil (Viagra) has been developed as a drug to treat male impotence. It has also been used to reduce symptoms (e.g. improved exercise capacity) in patients with pulmonary arterial hypertension. A case of subarachnoid haemorrhage (SAH) following the illicit use of sildenafil is reported.
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PMID:Subarachnoid haemorrhage: possibly caused by the illegitimate use of sildenafil citrate. 1926 10

PDE5 inhibitors have been clearly established as first-line therapy for the treatment of erectile dysfunction (ED). Three PDE5 inhibitors--sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis)--are currently approved by the FDA and the EMEA for use in ED, whereas sildenafil is also marketed under a different proprietary name (Revatio) for the treatment of pulmonary arterial hypertension (PAH). A forth PDE5 inhibitor, udenafil (Zydena), is currently marketed. In the present review the molecular basis and the mechanism of action of PDE5 inhibitors is discussed. In addition experimental and clinical data concerning their effects on different tissues, organs and systems is systematically reviewed and their possible beneficial action in numerous disorders is presented.
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PMID:PDE5 inhibitors: in vitro and in vivo pharmacological profile. 1986 Jun 92

Sildenafil citrate (Viagra), a cGMP-selective phosphodiesterase (PDE) inhibitor, is widely used to treat erectile dysfunction and pulmonary arterial hypertension. In contrast to its well established action on erectile dysfunction, little is known on the action of sildenafil on cGMP/cAMP signaling and testicular steroidogenesis. This study was designed to assess the effects of prolonged sildenafil treatment on NO synthase-dependent signaling and steroidogenic function of rat Leydig cells. Male adult rats were treated with Viagra (1.25 mg/kg body wt) daily for 30 days. In our studies, serum testosterone and ex vivo testosterone production significantly increased in sildenafil-treated animals. Human chorionic gonadotropin-stimulated testosterone production and cAMP accumulation were also significantly higher in Leydig cells obtained from sildenafil-treated rats. The expression of soluble guanylyl cyclase (GUCY1) subunits (Gucy1a1, Gucy1b1) significantly increased; cAMP-specific Pde4a, cGMP-specific Pde6c, and dual Pde1c and Nos2 were inhibited and expression of Nos3, protein kinase G1 (Pkg1), and Pde5 remained unchanged. Treatment of purified Leydig cells with NO donor caused a dose-dependent increase in both testosterone and cGMP production. Testosterone and cGMP production was significantly higher in Leydig cells obtained from sildenafil-treated animals. The stimulatory effect of NO donor was significantly enhanced by saturating concentrations of hCG in both Leydig cells obtained from control and sildenafil-treated animals. Occurrence of mature steroidogenic acute regulatory protein also increased in sildenafil treated animals in accord with increased cAMP and cGMP production. In summary, inhibition of PDE activity during prolonged sildenafil treatment increased serum testosterone level and Leydig cells' steroidogenic capacity by coordinated stimulatory action on cAMP and cGMP signaling pathway.
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PMID:Sildenafil treatment in vivo stimulates Leydig cell steroidogenesis via the cAMP/cGMP signaling pathway. 2066 85

We present a patient with an acute cervical spinal cord infarction resulting from the use of sildenafil (Viagra) in combination with his hypertension medication. Symptoms were acute and rapidly progressive, and MR imaging with DWI was crucial in confirming the diagnosis.
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PMID:Sildenafil-induced cervical spinal cord infarction. 2190 16


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