Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sildenafil (Viagra, Pfizer, Inc.) is a new orally effective therapy for the treatment of men with erectile dysfunction (ED). It is a specific and selective inhibitor of phosphodiesterase Type 5 (PDE5), an enzyme which is an important modulator of smooth muscle relaxation in the corpus cavernosum. In the presence of a sexual stimulus, inhibition of PDE5 results in improved smooth muscle relaxation within the sinusoids of the corpus cavernosum and the penile arteries. This results in improved erections in men with ED. In clinical trials, sildenafil has been found to be effective in improving the erections of large numbers of men with ED secondary to a range of causes. The presence of PDE5 in other tissues such as vascular smooth muscle results in side effects such as headache, flushing, indigestion and nasal congestion. These side effects are dose-dependent and well-tolerated. The introduction of sildenafil in many countries around the world has revolutionised the assessment and treatment of men with ED.
 ...
PMID:Sildenafil. 1124 56

Sildenafil is an oral treatment for erectile dysfunction (ED). It acts as an inhibitor of 3',5'-cyclic guanosine monophosphate-phosphodiesterase type 5. An effective treatment for ED is required to produce an erectile response sufficient for satisfactory sexual performance. This has been documented for sildenafil in men with ED of differing aetiologies and baseline severity in various types of clinical trials. Sildenafil treatment is characterised by a good tolerability profile and low treatment digcontinuation rate caused by treatment-related adverse effects. Most of the adverse effects associated with sildenafil are extensions of the pharmacological action of the drug. There is no significant difference in the adverse effect profile (headache, flushing, dyspepsia, nasal congestion and abnormal vision) of this agent as assessed by clinical data obtained either in the pre- and postlaunch periods. Because of its acceptable risk-benefit ratio, sildenafil can be prescribed to a very large group of patients with ED. The reports of serious cardiovascular events associated with the use of sildenafil (including anecdotal reports of deaths) have been very thoroughly analysed. A number of studies have not shown any difference in the risk of serious cardiovascular events in sildenafil- and placebo-treated patients. However, when making a risk-benefit evaluation, certain subgroups of patients need to be considered separately. In particular, sildenafil is contraindicated in patients receiving nitrate therapy. In some other subgroups of patients, the risks and benefits of treatment need to be assessed on an individual basis and it is hoped that additional data will clarify any possible risks associated with sildenafil administration such patients. It is helpful to compare the risk-benefit profile of sildenafil with the characteristics of other oral drugs for ED. According to the preliminary data, apomorphine and phentolamine are possible future options for the treatment of ED; however, there needs to be further clinical evaluation of these agents. Initial data have shown that sildenafil can be successfully combined with intracavernosal injection in patients nonresponders to either therapy. In conclusion, favourable characteristics make sildenafil suitable for the first-line therapy for a substantial proportion of patients with ED.
 ...
PMID:A risk-benefit assessment of sildenafil in the treatment of erectile dysfunction. 1133 Jun 55

Safety data from 546 men with erectile dysfunction (ED) enrolled in three double-blind, placebo-controlled studies conducted in distinct regions of Latin America were pooled and analyzed. The most commonly reported adverse events of all causalities associated with sildenafil treatment were headache (19%), flushing (14%), dyspepsia (6%), and nasal congestion (4%), reflecting the inhibitory effects of sildenafil on cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5) in the peripheral vasculature, gastroesophageal sphincter, and nasal mucosa. Visual symptoms were reported in 5.5%, reflecting sildenafil's minor inhibitory effects on cGMP-specific PDE6 in the retina. These adverse events were generally transient and mild, and rarely resulted in discontinuation of sildenafil therapy. Thus, in this representative sample of Latin American men with ED, including those with concomitant stable cardiovascular disease, sildenafil treatment was well tolerated with an incident rate of adverse events similar to reports from other patient populations.
 ...
PMID:Tolerability and safety profile of sildenafil citrate (Viagra) in Latin American patient populations. 1216 69

Potential vasodilator side effects of sildenafil such as headache, flushing, dyspepsia, heartburn, nasal congestion, dizziness and visual changes have been frequently observed. We report a 79-year-old man who developed severe vestibular neuritis-like symptoms (horizontal nystagmus with rotatory components and vomiting) two hours after taking 50 mg sildenafil. Additionally, the patient complained of tinnitus in both ears. Internal and neurological examination revealed no pathological findings and the patient had no history of cardiovascular disease. The symptoms lasted for 24 hours and then resolved completely. All of the patient's complaints indicated a drug-related phenomenon. This drug related adverse reaction should be included in the long list of potential side effects of sildenafil.
 ...
PMID:Vestibular symptoms as a complication of sildenafil: a case report. 1240 37

The objectives of this study were to evaluate the efficacy and tolerability of high dose sildenafil as a salvage therapy for patients refractory to the maximum recommended dose of sildenafil. Fifty four fully evaluated patients with chronic erectile failure (ED) who had previously failed to respond to a home trial of sildenafil (100 mg) with erections suitable for sexual intercourse were studied. Each man was treated at home with sildenafil at escalating doses of up to 200 mg until either maximal response or intolerable adverse effects occurred. Erectile function was quantified using the erectile function domain of the International Index of Erectile Function (IIEF) before treatment, with sildenafil 100 mg and with maximal dose of sildenafil and a global efficacy question after 4 weeks of treatment. The mean age of the study group was 59.6+/-11.2 y. 13/54 (24%) had arteriogenic ED, 16/54 (30%) had mixed vasculogenic ED, 9/54 (17%) had cavernosal veno-occlusive dysfunction, 11/54 (20%) had post radical retropubic prostatectomy ED and 5/54 (9%) had psychogenic ED. 13/54 (24.1%) responded to sildenafil at a median maximal dose of 200 mg, 4/13 required 150 mg and 9/13 required 200 mg. 41/54 (76%) failed to respond to sildenafil. Mean IIEF question 3 and 4 scores were 1.5 and 1.4 at baseline, 2.2 and 1.9 with sildenafil 100 mg, 2.8 and 2.5 with sildenafil 150 mg and 3.0 and 2.9 with sildenafil 200 mg, respectively. After 4 weeks, treatment was regarded as having improved their erections by 37%, 46.3% and 68% of patients with sildenafil 100 mg, 150 mg and 200 mg, respectively. 34/54 (63%) reported adverse effects with maximal dose sildenafil comprising headache (19), facial flushing (32), dyspepsia (14), nasal congestion (11), dizziness (5) and visual disturbances (5). 4/13 (31%) responders refused to continue treatment due to adverse effects.In conclusion, sildenafil at doses of up to 200 mg is an effective salvage therapy for 24.1% of previous sildenafil non-responders but is limited by a significantly higher incidence of adverse effects and a 31% treatment discontinuation rate.
 ...
PMID:High dose sildenafil citrate as a salvage therapy for severe erectile dysfunction. 1460 83

The mechanism of action of the phosphodiesterase type 5 (PDE5) inhibitors (i.e., sildenafil, tadalafil, and vardenafil) involves inhibition of the PDE5 isoenzyme located in penile vascular smooth muscle cells. Sexual stimulation triggers the release of nitric oxide (NO), stimulating the release of guanylyl cyclase, leading to an increase in intracellular cyclic guanosine monophosphate (cGMP) concentrations, a decrease in intracellular calcium, and ultimately relaxation of the vascular smooth muscle in the corpus cavernosum and penile erection. The PDE5 inhibitors have no effect on the penis in the absence of sexual stimulation. Although the various PDE5 inhibitors differ with respect to selectivity and pharmacokinetic profiles, efficacy and safety of these agents are comparable in broad populations of men with erectile dysfunction (ED), including those with diabetes or those taking multiple antihypertensive agents. The most frequently reported adverse events of the PDE5 inhibitors are related to their mild vasodilatory effects and include headache, flushing, dyspepsia, and nasal congestion or rhinitis. Side effects are generally reversible and tend to diminish during continued treatment. Differences in pharmacokinetic properties among the PDE5 inhibitors include the fact that sildenafil and vardenafil have a shorter duration of action (approximately 4 h) compared with the longer period of responsiveness observed with tadalafil (up to 36 h). In addition, in the presence of high-fat food, absorption of sildenafil and vardenafil may be delayed; however, the rate and extent of tadalafil absorption are unaffected by high-fat food.
 ...
PMID:Phosphodiesterase type 5 inhibitor differentiation based on selectivity, pharmacokinetic, and efficacy profiles. 1511 91

Inhibitors of phosphodiesterase type 5 (PDE-5) are well established as an oral treatment for the majority of patients with erectile dysfunction (ED). PDE-5 is found in high concentration in smooth muscle cells of the corpora cavernosa. However, enzymes of the PDE family are also expressed in various other tissues, including the brain. Little is known about its effects on the central nervous system (CNS), although it has been suggested that PDE-5 inhibitors might cross the blood-brain barrier. Side effects, such as headache, nasal congestion, flushing, nausea, are much more common. We describe a patient who had a transient global amnesia (TGA) after his first-ever use of tadalafil, a potent PDE-5 inhibitor. Despite the fact that the aetiology of TGA has not entirely been clarified at present, we consider the hypothesis of a causal relationship as tempting with respect to the current hypotheses of TGA pathophysiology. This case, together with others, suggests that PDE-5 inhibitors might be capable of exerting adverse effects in the CNS. Physicians should be aware of the possibility of neurological disturbances when prescribing PDE-5 inhibitors for ED.
 ...
PMID:Transient global amnesia after intake of tadalafil, a PDE-5 inhibitor: a possible association? 1567 2

Inhibition of phosphodiesterase-5 (PDE5) reduces the degradation of cyclic guanosine monophosphate, which allows erectile function to occur by relaxation of penile smooth muscle. Three PDE5 inhibitors (sildenafil, tadalafil, and vardenafil) in a range of doses are available. PDE5 therapy, compared with placebo, significantly improves scores on the International Index of Erectile Function and has been found to be effective in special clinical populations, such as those with prostate cancer, diabetes, and cardiovascular disease. Sildenafil and vardenafil show some interaction with food intake. Time to onset of action is usually 30-120 minutes, but there are reports of shorter times to onset of action. The duration of action of sildenafil and vardenafil is about 4 hours, whereas that of tadalafil is about 36 hours. The overall safety of the treatments is good, even in patients with a history of cardiovascular disease. However, there is a risk of hypotension if nitrates are given concurrently. Increased QTc intervals have been reported, the longest with vardenafil, shortest with tadalafil, and intermediate with sildenafil. Priapism and prolonged erection are rare adverse events. Common side-effects include headache, facial flushing, nasal congestion, and dyspepsia. There may be interactions with other medications metabolized in a similar way, such as erythromycin and HIV protease inhibitors.
 ...
PMID:The efficacy and safety of PDE5 inhibitors. 1615 23

A 21-year-old man, who had suddenly developed dyspnea with sneeze, cough and nasal congestion following supper, was admitted to our hospital because of hypoxemia and hypercapnia. Physical examination revealed wheezing in all lung fields and skin flushing. He took home-made Okonomi-yaki made from flour, which had been opened few months ago, and then had been remained uncooked at room temperature. Skin prick tests showed positive for problem flour and mite, but negative for just opened control flour. Collectively, we gave his diagnosis of anaphylaxis caused by mite-contaminated Okonomi-yaki.
 ...
PMID:[A case of anaphlaxis caused by mite-contaminated Okonomi-yaki]. 1688 95

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.
 ...
PMID:Phosphodiesterase 5 inhibitors--drug design and differentiation based on selectivity, pharmacokinetic and efficacy profiles. 1701 39


<< Previous 1 2 3 4 Next >>