Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013395 (dyspepsia)
 4,879 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The discovery that inhibition of phosphodiesterase-5 (PDE5) reduces the degradation of cGMP, allowing erectile function to occur by relaxation of penile smooth muscle, represents a revolutionary approach or the treatment of erectile dysfunction (ED). Three PDE5 inhibitors (sildenafil, tadalafil, and vardenafil) are clinically available at this time, and extensive drug design efforts are registered for finding agents with a better activity, enhanced selectivity and reduced side effects. Many classes of such compounds have been reported, belonging to diverse chemical entities. The drug design has been very much facilitated after the report of the X-ray crystal structure of the PDE5 catalytic domain in complex with the three clinically used derivatives. PDE5 inhibitor therapy, has been found to be effective in special clinical populations, such as those with prostate cancer, diabetes, and cardiovascular disease. The duration of action of sildenafil and vardenafil is of about 4 hours, whereas that of tadalafil is of about 36 hours, and the overall safety of the treatments is good. There is a risk of hypotension if nitrates are given concurrently with the PDE5 inhibitors. Common side-effects include headache, facial flushing, nasal congestion, dyspepsia and transient visual impairment. There are pharmacological interactions between these drugs and other medications metabolized by the cytochrome P450 (P3A4 isoform), such as the azole antifungals, erythromycin and the HIV protease inhibitors.
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PMID:Phosphodiesterase 5 inhibitors--drug design and differentiation based on selectivity, pharmacokinetic and efficacy profiles. 1701 39

To evaluate the safety and efficacy of vardenafil in primary care, we undertook a post-marketing surveillance study in 384 men with erectile dysfunction (ED), enrolled by 22 family physicians in Korea, from July 2004 to August 2005. Of the 384 patients enrolled, 343 (89.3%) returned for efficacy assessment and safety evaluation. Among the latter, 279 patients (81.3%) reported that their erectile function improved, 292 (92.1%) showed enhanced IIEF (International Index of Erectile Function)-5 scores and 265 (77.9%) responded that they were 'very satisfied' or 'satisfied' with vardenafil treatment. The most frequent reason for patient satisfaction with vardenafil was erectile potency (62.4%), followed by safety (42.4%), rapid onset (35.3%), adequate duration of efficacy (28.5%) and easy administration (25.9%). A total of 23 adverse events were observed in 18 patients, with the most frequent being hot flushes (3.2%), followed by headache (1.2%), nasal congestion (0.6%), color vision disturbance (0.3%), dizziness (0.3%), dry mouth (0.3%), dyspepsia (0.3%), nausea (0.3%) and diarrhea (0.3%). Only one patient discontinued vardenafil as a direct result of an adverse event. These results suggest that vardenafil prescribed by primary care physicians improved erectile function and was well tolerated by patients with ED.
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PMID:Post-marketing surveillance study of the efficacy and safety of vardenafil among patients with erectile dysfunction in primary care. 1728 34

Sildenafil (Viagra) is a selective phosphodiesterase type 5 inhibitor (PDE5-I) approved for treatment of erectile dysfunction. Although relatively well-tolerated, sildenafil is associated with undesired effects including headache, flushing, dyspepsia, nasal congestion, and visual disturbances. In the present study we explored the impact of sildenafil on nasal airway parameters in young potent men. Eleven men (age 26.0 +/- 1.8 years) with normal BMI (25.7 +/- 0.5) and without nasal respiratory disorders were enrolled in a double-blind, crossover study. All men underwent evaluation of systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), SpO2%, acoustic rhinometry, and nasal endoscopy before and after placebo or sildenafil (50 mg) plus visual sexual stimulation (VSS). Nasal examination was performed using 0 degrees rigid telescopes, 4 mm in diameter. A Student's t test was used for direct comparisons, while the Kruskal-Wallis test (K-W) was utilized for multiple comparisons. After administration of sildenafil plus VSS, the minimum cross sectional area (MCA) was significantly lower that observed with either placebo (P = 0.03) or sildenafil alone (P = 0.003). However, the post-stimulation values did not demonstrate any significant differences among the different treatment arms (P = 0.48; DF = 2; K-W test). In contrast, endonasal volume (VOL) was significantly lower after sildenafil + VSS (P = 0.01), but not after placebo + VSS (P = 0.18). None of the other parameters monitored showed any significant variations. Rhinoscopy showed a characteristic increase of the volume of the inferior turbinates, with subjective differences between placebo and sildenafil. These preliminary results suggest that sildenafil reduces nasal volume, and that sexual stimulation may decrease nasal airflow by itself.
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PMID:Nasal congestion after visual sexual stimulation with and without sildenafil (Viagra): a randomized placebo-controlled study. 1790 71

Prevalence and severity of erectile dysfunction (ED) increase with aging and are often associated with illnesses, like diabetes mellitus, heart disease, and hypertension, pathologically characterized by endothelial dysfunction and whose prevalence increases with age. The assumption that ED is mainly a neurovascular disease is supported by the evidence that specific phosphodiesterase type 5 (PDE5) inhibition produces an efficient erection in a wide range of ages and conditions. The availability of specific PDE5 inhibitors has enabled the development of effective treatment strategies, in this contest, tadalafil may be considered as the least "typical" PDE5 inhibitor. In clinical trials, tadalafil significantly enhanced, in patients of different ages, all efficacy outcomes across disease etiologies and severities. With an effectiveness lasting up to 36h, tadalafil allows patients to choose when to have sexual activities without the need to time it, showing positive feedback in terms of quality of life related to the treatment. Headache and dyspepsia were the most frequent side-effects of tadalafil, followed by back pain, nasal congestion, myalgia, and flushing, but the impact that long time action could have on effectiveness and safety is not yet entirely defined. The aim of this article is to critically review the available evidence from the tadalafil clinical research program and give the physician a rational approach for intervention in the treatment of ED and related diseases.
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PMID:Tadalafil in the treatment of erectile dysfunction; an overview of the clinical evidence. 1804 21

The phosphodiesterase type 5 (PDE-5) inhibitors-sildenafil, vardenafil, and tadalafil-are used primarily in erectile dysfunction, but sildenafil is also indicated for pulmonary hypertension. Common adverse effects of vardenafil include headache, flushing, nasal congestion, dyspepsia, and nausea. Recently, PDE-5 inhibitors have been associated with adverse vision effects, and emerging evidence now indicates that they may also be responsible for hearing changes and hearing loss. We describe a patient who developed unilateral sudden sensorineural hearing loss possibly related to the use of vardenafil for erectile dysfunction. To our knowledge, only one other case of hearing loss related to this drug class has been published. Our patient was a 57-year-old man who came to the emergency department with right-sided mild-to-moderate hearing loss in the 500-3000-Hz range, confirmed by audiogram, that occurred after ingestion of vardenafil. The patient was hospitalized 2 days later for administration of intravenous dexamethasone, followed by oral prednisone. He reported that his hearing had improved on the fourth hospital day and was discharged 3 days later, continuing to taper the prednisone on an outpatient basis. A repeat audiogram after 10 days of corticosteroid therapy confirmed that his hearing in the 500-3000-Hz range was within normal limits. Use of the Naranjo adverse drug reaction probability scale indicated a possible (score of 3) adverse reaction of sudden sensorineural hearing loss associated with vardenafil consumption. We also performed an analysis of hearing loss cases related to PDE-5 inhibitors in the United States Food and Drug Administration's Adverse Event Reporting System database to compare the characteristics of our patient with those of other reported adverse event cases. Based on the temporal relation of the sudden sensorineural hearing loss to this patient's drug consumption, we propose that the vardenafil is a likely cause of the hearing loss. This case provides further evidence that PDE-5 inhibitor consumption should be considered as a possible cause in patients presenting with sudden sensorineural hearing loss.
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PMID:Sudden sensorineural hearing loss associated with vardenafil. 2003 Apr 81

Male erectile dysfunction is common and frustrating after the age of forty years. Erectile dysfunction is a cause of misery, relationship difficulties, and significantly reduced quality of life. Sildenafil citrate (Viagra) has shown promising results in recently published clinical trials. Sildenafil is a potent and competitive inhibitor of cGMp specific phosphodiesterase-5, predominant isoenzyme in the human corpus cavernosum. It is effective in erectile dysfunction of diverse origin, however it requires a patent vascular system to be effective. It is not effective in patients with endocrinal impotence, loss of libido, premature ejaculation or infertility. Its main adverse effects are headache, flushing, dyspepsia, diarrhoea, nasal congestion, indigestion, visual disturbances, dizziness and rash. Ventricular tachycardia and acute myocardial infraction have been reported in patients of ischaemic heart disease after consumption of sildenafil. Six deaths have been reported in patients taking nitrates. In India it is likely to be prescribed by a primary care physician without complete evaluation of patient on complaint of impotence. Hence the ethical question of who should prescribe this drug should be addressed by medical fraternity and proper guidelines formulated to avoid misuse of sildenafil. Phosphodiesterase is distributed in nerve, central nervous system, and systemic vasculature, hence long-term effects of drug on these tissues has to be ascertained. It should be made mandatory to report all adverse drug reactions to ADR monitoring centres. It is a wonder for those who require it, but has potentially dangerous adverse effects and drug interactions and hence is and not a wonder pill for all kinds of impotence.
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PMID:VIAGRA : IS IT A WONDER DRUG ? 2736 78


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