Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sildenafil citrate (Viagra) is a phosphodiesterase type V inhibitor used to treat erectile dysfunction. Ten men with idiopathic Parkinson's disease (PD) and erectile dysfunction were prescribed 50-100 mg sildenafil citrate to use in eight sexual encounters over a 2-month period. Patients underwent Unified Parkinson's Disease Rating Scale (UPDRS) evaluations and completed a Beck's Depression Inventory (BDI) and a Sexual Health Inventory-M version (SHI-M) at baseline and after 8 weeks. There was statistically significant improvement in total SHI-M scores (23.8 +/- 2.0 vs 16.6 +/- 2.8; p = 0.01), overall sexual satisfaction (p = 0.03), satisfaction with sexual desire (p = 0.04), ability to achieve erection (p = 0.02), ability to maintain erection (p = 0.03), and ability to reach orgasm (p = 0.04) with use of sildenafil citrate. UPDRS and BDI scores were not significantly changed. Side effects included headache in one patient during three sexual encounters. In this open-label study, sildenafil citrate significantly improved sexual function in men with PD and erectile dysfunction.
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PMID:Sildenafil citrate (Viagra) for the treatment of erectile dysfunction in men with Parkinson's disease. 1075 81

The long-term efficacy and safety of oral Viagra (sildenafil citrate), a selective phosphodiesterase 5 inhibitor, and the effect of withdrawing treatment were evaluated in men with erectile dysfunction (ED). In 233 men with ED of psychogenic or mixed organic/psychogenic aetiology, 16 weeks of open-label, flexible-dose sildenafil treatment (10-100 mg) was followed by eight weeks of double-blind, fixed-dose, randomised withdrawal to placebo or continued treatment with sildenafil. Sildenafil was taken as needed (not more than once daily) approximately 1 h prior to sexual activity. The main outcome measures were a global efficacy question, a sexual function questionnaire, an event log of erections, and adverse event recording. In the open-label phase, 200 of 216 patients (93%) reported improved erections with sildenafil; 28 patients (12%) discontinued treatment. In the double-blind phase, the significant improvements in the frequency and duration of erections were maintained in the sildenafil group but returned to pre-treatment values in patients on placebo (P values < 0.0001 versus placebo). The most frequent adverse events in the sildenafil group during the double-blind phase were flushing (7%), headache (6%), and dyspepsia (5%). Of the 192 patients enrolled in the 1-y extension, 90% completed the study; only two patients (1%) were withdrawn due to lack of efficacy. In men with ED of psychogenic or mixed aetiology, oral sildenafil is effective and well-tolerated both at the initiation of therapy and during long-term treatment. For most patients, sildenafil treatment must be continued for improvements in erectile function to be maintained.
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PMID:Long-term efficacy and safety of oral Viagra (sildenafil citrate) in men with erectile dysfunction and the effect of randomised treatment withdrawal. 1104 12

Sildenafil citrate (Viagra) has been shown to be an effective treatment for erectile dysfunction (ED) of organic aetiology. This study assessed the efficacy and tolerability of sildenafil for treating ED of psychogenic and mixed psychogenic/organic aetiology. Men with ED of psychogenic and mixed aetiology were randomised in a double-blind, fixed-dose study to placebo (n = 95) or sildenafil 10 mg (n = 90), 25 mg (n = 85), or 50 mg (n = 81) once daily for 28 days. Efficacy was evaluated with two global efficacy questions, a patient log of erectile activity, a sexual function questionnaire and a partner questionnaire. Patients receiving sildenafil had significantly more grade 3 (hard enough for penetration) or grade 4 (fully hard) erections per week than patients receiving placebo, and a greater proportion of patients receiving sildenafil reported that treatment had improved their erections (p < 0.001). Results of the sexual function questionnaire demonstrated significant improvement for patients with ED receiving sildenafil compared with patients receiving placebo for frequency, hardness and duration of erections (p < 0.01), and for enjoyment of sexual intercourse and satisfaction with sex life (p < 0.05). The results of the partner questionnaire were consistent with the results reported by patients and showed that treatment with sildenafil was associated with significant improvement in the partners' own sex lives (p < 0.001). Adverse events were mostly mild to moderate in nature. The commonest adverse events were headache, dyspepsia, flushing, myalgia, arthralgia and flu syndrome. Discontinuations due to treatment-related adverse events were few, ranging from 1.1% to 6.2% for patients receiving different doses of sildenafil and 4.2% for patients receiving placebo. Sildenafil is an effective and well-tolerated treatment for ED of psychogenic or mixed aetiology with once-daily dosing.
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PMID:Sildenafil citrate (Viagra) is effective and well tolerated for treating erectile dysfunction of psychogenic or mixed aetiology. 1122 Sep 82

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.
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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.
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PMID:A risk-benefit assessment of sildenafil in the treatment of erectile dysfunction. 1133 Jun 55

Hypertension is an important risk factor for erectile dysfunction (ED). Consequently, there is a high coincidence between hypertension and ED. Oral sildenafil (Viagra) is an effective treatment for ED in patients with treated or untreated hypertension. The most common adverse events of sildenafil (headache, flushing, hypotension) result from its moderate vasodilating properties. The concomitant use of sildenafil and organic nitrates is contraindicated because it may lead to a potentiation of the decreases in blood pressure and thus cause life-threatening hypotension. In contrast, the concomitant use of sildenafil and different classes of antihypertensive agents (beta-blockers, alpha-blockers, diuretics, ACE inhibitors, calcium antagonists) may lead to additive but not to potentiating blood pressure decreases. Thus, this combination is unlikely to cause clinically significant hypotension or an increased incidence of adverse events. Sildenafil is an effective and well-tolerated treatment for ED in patients taking concomitant antihypertensive medication, including those on multidrug regimens.
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PMID:[Interaction between sildenafil and antihypertensive drugs: what is evidence-based?]. 1159 59

Safety and tolerability of sildenafil citrate was assessed in a population subset of 60 Singaporean men with erectile dysfunction taken from the Asian Sildenafil Efficacy and Safety Study (ASSESS-I), a double-blind, placebo-controlled, flexible-dose study. The men, from two centres, with > or = 6 months' history of erectile dysfunction, were randomized to two treatment arms for 12 weeks. One group (30 patients) received sildenafil (initial dose 50 mg taken 1 h before sexual activity for the first 2 weeks, increased to 100 mg or decreased to 25 mg, according to efficacy and/or tolerability). The remaining 30 patients received a matching placebo. Incidence and type of adverse effects were evaluated at 2, 4, 8 and 12 weeks. Nine patients (30.0%) on sildenafil (33.1% in the full ASSESS-I study) and one patient (3.3%) on placebo (22.8% in the full ASSESS-I study) experienced treatment-related adverse events, the most frequent being headache in the sildenafil group (reported by five patients [16.7%]; 11.0% in the full ASSESS-I study). Flushing, visual disturbance, dizziness, insomnia, myalgia and back pain each occurred in one patient in the sildenafil group (3.3%); in the placebo group, one patient (3.3%) had headache. Importantly, the incidence of cardiovascular and respiratory system adverse events were relatively less than in the full ASSESS-I population (cardiovascular 3.3% in the present study versus 10.2% in the full ASSESS-I population; respiratory 3.3% versus 5.5%). All adverse events were transient and mild, and did not lead to treatment withdrawal. There was no effect on sitting blood pressure, heart rate or standard laboratory parameters; more importantly, there was no incidence of myocardial infarction, stroke or priapism. These results should reassure Singaporean patients and their physicians of the safety of sildenafil for erectile dysfunction.
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PMID:Clinical safety profile of sildenafil in Singaporean men with erectile dysfunction: pre-marketing experience (ASSESS-I evaluation). 1202 21

A 12-week, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of flexible-dose sildenafil citrate (Viagra) treatment (25, 50 or 100 mg) in Brazilian and Mexican men with erectile dysfunction (ED) of broad-spectrum etiology. Efficacy was assessed on the basis of responses to the 15-item International Index of Erectile Function (IIEF) questionnaire, completed at baseline and after 12 weeks of treatment. At end point, mean scores for all IIEF domains of sexual function (erectile function, orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction) were significantly (P<0.0001) higher in the sildenafil group (n=109) than in the placebo group (n=105). These findings confirm the significant increases in frequency of penetration and frequency of maintained erections reported previously. Sildenafil treatment was well tolerated. The most common adverse events were headache and flushing. In conclusion, sildenafil is a well-tolerated and effective treatment for ED of broad-spectrum etiology in Latin American men.
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PMID:Efficacy and safety of flexible-dose oral sildenafil citrate (Viagra) in the treatment of erectile dysfunction in Brazilian and Mexican men. 1216 65

Our objectives were: (1) to determine the efficacy, safety, and tolerability of sildenafil citrate (Viagra) administered to men with broad-spectrum erectile dysfunction (ED) in southern Latin America; and (2) to correlate Rigiscan measurements assessing ED etiology with the investigator's assessment. A total of 141 men with broad-spectrum ED (mean age 57) were enrolled in a randomized, 12-week, double-blind, placebo-controlled, flexible-dose escalation study of sildenafil. After the 12-week treatment period, the mean score for the primary efficacy variables had risen significantly: for the sildenafil group, 66.2% from baseline for question 3 of the International Index of Erectile Function and 77.6% for question 4, vs 15.1% and 21.2% for the placebo group, respectively (P<0.0001). Rigiscan data confirmed investigator assessments of etiology. Headache and flushing, usually mild and transient, were the most common adverse events. Sildenafil was an effective, well-tolerated treatment for men in southern Latin America with broad-spectrum ED.
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PMID:Sildenafil citrate (Viagra) in the treatment of men with erectile dysfunction in southern Latin America: a double-blind, randomized, placebo-controlled, parallel-group, multicenter, flexible-dose escalation study. 1216 66

Cyclic nucleotides are important hemodynamic regulators in many tissues. Glyceryl trinitrate markedly dilates large cerebral arteries and increases cGMP. Here, the authors study the effect of sildenafil, a selective inhibitor of cGMP-hydrolyzing phosphodiesterase 5 on cerebral hemodynamics and headache induction. Ten healthy subjects were included in a double-blind, placebo-controlled crossover study where placebo or sildenafil 100 mg (highest therapeutic dose) were administered on two separate days. Blood velocity in the middle cerebral artery (Vmca) was recorded by transcranial Doppler, and regional cerebral blood flow in the perfusion area of the middle cerebral artery (rCBFmca) was measured using single photon emission computed tomography and xenon inhalation. Radial and temporal artery diameters were studied using high-frequency ultrasound. Blood pressure and heart rate were recorded repeatedly. Headache responses and tenderness of pericranial muscles were scored verbally. Sildenafil caused no significant changes in rCBFmca, Vmca, or in temporal or radial artery diameter, but heart rate increased and diastolic blood pressure decreased significantly compared to placebo. Despite the lack of cerebral arterial dilatation, sildenafil caused significantly more headache than placebo. The present results show that sildenafil 100 mg does not dilate cerebral or extracerebral arteries but nevertheless causes headache, which may be attributed to nonvascular mechanisms.
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PMID:The phosphodiesterase 5 inhibitor sildenafil has no effect on cerebral blood flow or blood velocity, but nevertheless induces headache in healthy subjects. 1221 18


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