Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Forty-eight men with Parkinson's disease (PD) were interviewed utilizing a questionnaire which evaluated autonomic function. The study population included PD patients (mean age: 65.8 years, mean duration of PD: 8 years) and 32 elderly healthy nonparkinsonian males (mean age: 70.4 years). We found a significantly higher prevalence of the following symptoms of autonomic dysfunction in the parkinsonian patients: erectile dysfunction (60.4 vs. 37.5%), sensation of incomplete bladder emptying (41.6 vs. 15.6%), urgency (45.8 vs. 3.125%), constipation (43.9 vs. 6.25%), dysphagia (22.9 vs. 6.25%) and orthostatic dizziness (21.95 vs. 0%). Eighty-nine percent of parkinsonian patients had at least one of these autonomic symptoms, compared to 43% of control subjects (p less than 0.05). This study is the first comprehensive survey of autonomic symptomatology in PD compared to elderly healthy controls and confirms that autonomic nervous system dysfunction is a pervasive problem in PD. Erectile dysfunction is a significant problem in this patient group and contributes to deterioration in the quality of life.
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PMID:Autonomic dysfunction in men with Parkinson's disease. 159 69

A comparative study in 103 unselected patients with erectile dysfunction between MUSE up to 1000 micrograms and intracavernous Alprostadil (Prostavasin) up to 20 micrograms provided total response-rates of 43% (MUSE) vs 70% (Prostavasin). Complete rigid erections were reached in 10% (MUSE) vs 48% (Prostavasin). The average end-diastolic flow values in the deep penile arteries ranged between 9.2-9.4 cm/s after MUSE and 4.5-4.8 cm/s after i.c. Alprostadil confirming the investigator's assessment, that in the vast majority of patients MUSE were not able to induce a complete cavernous smooth muscle relaxation. In terms of side effects the reported penile pain/ burning-rate after MUSE was 31.4% compared to 10.6% after i.c. Alprostadil. In addition after MUSE clinically relevant systemic side-effects like dizziness, sweating and hypotension occurred in 5.8% with syncope in 1%. No circulatory side-effects were encountered after i.c. Alprostadil. Urethral bleeding after MUSE-application was observed in 4.8%. Due to the superior efficacy and lower side-effects self-injection therapy with Alprostadil remains the 'Gold Standard' in the management of male impotence. MUSE should be reserved for a subset of patients suffering from erectile dysfunction.
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PMID:Transurethral alprostadil with MUSE (medicated urethral system for erection) vs intracavernous alprostadil--a comparative study in 103 patients with erectile dysfunction. 954 92

Sildenafil citrate, an oral therapy for erectile dysfunction, is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), the predominant isozyme metabolizing cGMP in the corpus cavernosum. Chemically, it is a compound of the pyrazolo-pyrimidinyl-methylpiperazine class. Sildenafil has no direct relaxant effect on human corpus cavernosum but enhances the relaxant effect of nitric oxide (NO) on the corpus cavernosum by inhibiting PDE5, which is responsible for degradation of cGMP in this tissue. When sexual stimulation causes local release of NO, inhibition of PDE5 by sildenafil increases concentrations of cGMP in the corpus cavernosum, causing smooth muscle relaxation and blood flow into the penis, resulting in an erection. Sildenafil at recommended doses has no effect in the absence of sexual stimulation. The drug is rapidly absorbed after oral administration, with absolute bioavailability of 40%. Its pharmacokinetics are dose proportional over the recommended dosage range. Maximum plasma concentrations are reached within 30 to 120 minutes after oral dosing in the fasting state. Sildenafil is cleared predominantly by the hepatic microsomal isoenzymes CYP3A4 (major route) and CYP2C9 (minor route). Clinical studies assessed the effect of sildenafil on the ability of men with erectile dysfunction to engage in sexual activity and, specifically, to achieve and maintain an erection sufficient for satisfactory sexual intercourse. Sildenafil was evaluated at doses of 25, 50, and 100 mg in randomized, double-masked, placebo-controlled clinical trials of up to 6 months' duration. The drug was administered to hundreds of patients aged 19 to 87 years having erectile dysfunction of various etiologies for a mean duration of 5 years. Sildenafil was associated with statistically significant improvement in erectile function compared with placebo. Adverse effects reported at a rate of >2% were headache, flushing, dyspepsia, nasal congestion, urinary tract infection, abnormal vision, diarrhea, dizziness, and rash. No cases of priapism were reported. The use of sildenafil is contraindicated in men who are taking organic nitrates, because of the potential for a precipitous decrease in blood pressure. Postmarketing reports and surveillance have revealed at least 39 deaths with sildenafil use in men having a history of heart disease, men taking nitrate medications, and men in poor physical health due to lack of exercise. Many of the men who experienced serious adverse effects or death had a variety of concomitant diseases and were taking multiple medications.
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PMID:Safety and efficacy of sildenafil citrate in the treatment of male erectile dysfunction. 991 1

Sildenafil, a selective inhibitor of phosphodiesterase type 5 (PDE5), is the first in a new class of orally effective treatments for erectile dysfunction. During sexual stimulation, the cavernous nerves release nitric oxide (NO), which induces cyclic guanosine monophosphate (cGMP) formation and smooth muscle relaxation in the corpus cavernosum. Sildenafil facilitates the erectile process during sexual stimulation by inhibiting PDE5 and thus blocking the breakdown of cGMP. Sildenafil alone can cause mean peak reductions in systolic/diastolic blood pressure of 10/7 mm Hg that are not dose related, whereas the heart rate is unchanged. Sildenafil and nitrates both increase cGMP levels in the systemic circulation but at different points along the NO-cGMP pathway. The combination is contraindicated because they synergistically potentiate vasodilation and may cause excessive reductions in blood pressure. Erectile dysfunction is a significant medical condition that shares numerous risk factors with ischemic heart disease, and hence a substantial overlap exists between these patient groups. From extensive clinical trials, the most commonly reported cardiovascular adverse events in patients treated with sildenafil were headache (16%), flushing (10%), and dizziness (2%). The incidences of hypotension, orthostatic hypotension, and syncope and the rate of discontinuation of treatment due to adverse events were <2% and were the same in patients taking sildenafil and those taking placebo. Retrospective analysis of the concomitant use of antihypertensive medications (beta blockers, alpha blockers, diuretics, angiotensin-converting enzyme inhibitors, and calcium antagonists) in patients taking sildenafil did not indicate an increase in the reports of adverse events or significant episodes of hypotension compared with patients treated with sildenafil alone. In clinical trials, the incidence of serious cardiovascular adverse events, including stroke and myocardial infarction, was the same for patients treated with sildenafil or placebo. Concurrent disease states, such as renal or hepatic impairment, or concomitant use of inhibitors of the cytochrome P450 isozyme CYP3A4 could increase systemic exposure to sildenafil. Since the US market launch in April 1998, monitoring of spontaneous adverse event reports in association with sildenafil has demonstrated a pattern that is generally consistent with the experience observed during clinical development, with the exception of infrequent reports of priapism. In conclusion, extensive clinical testing has shown that overall treatment with sildenafil for up to 1 year is well tolerated and is associated with a low incidence of adverse events that result in discontinuation of treatment in <3% of patients.
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PMID:Overall cardiovascular profile of sildenafil citrate. 1007 41

Treatment with St John's wort extract tablets (hypericum Ze 117) and the commonly used slow serotonin reuptake inhibitor (SSRI) fluoxetine was compared in patients with mild-moderate depression with entry Hamilton Depression Scale (HAM-D) (21-item) in the range 16-24, in a randomized, double-blind, parallel group comparison in 240 subjects; fluoxetine: 114 (48%), hypericum: 126 (52%). After 6 weeks' treatment, mean HAM-D at endpoint decreased to 11.54 on hypericum and to 12.20 on fluoxetine (P < 0.09), while mean Clinical Global Impression (CGI) item I (severity) was significantly (P < 0.03) superior on hypericum, as was the responder rate (P = 0.005). Hypericum safety was substantially superior to fluoxetine, with the incidence of adverse events being 23% on fluoxetine and 8% on hypericum. The commonest events on fluoxetine were agitation (8%), GI disturbances (6%), retching (4%), dizziness (4%), tiredness, anxiety/nervousness and erectile dysfunction (3% each), while on hypericum only GI disturbances (5%) had an incidence greater than 2%. We concluded that hypericum and fluoxetine are equipotent with respect to all main parameters used to investigate antidepressants in this population. Although hypericum may be superior in improving the responder rate, the main difference between the two treatments is safety. Hypericum was superior to fluoxetine in overall incidence of side-effects, number of patients with side-effects and the type of side-effect reported.
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PMID:Equivalence of St John's wort extract (Ze 117) and fluoxetine: a randomized, controlled study in mild-moderate depression. 1075 36

Sildenafil is highly effective for treating erectile dysfunction (ED). However, its use has been associated with serious adverse events including myocardial infarctions and strokes, and 130 verifiable plus 112 unverified deaths reported to the US Food and Drug Administration during the 8 months after sildenafil was introduced in the US, and 522 reported deaths during the 13.5 months after its introduction. Moreover, some events have occurred in men taking their first dose of the agent, suggesting that sildenafil, like some drugs that affect blood pressure, may provoke a first-dose reaction. This possibility warrants extra caution to be used when initiating treatment with sildenafil. Such caution is not currently provided by the current dosage guidelines that, for example, recommend the use of sildenafil 50 mg initially for most men between the ages of 18 and 65 years, despite wide differences in bodyweight, age, drug metabolism, health status and usage of other medications. It can be difficult to identify the patient who may be unusually sensitive to the effects of sildenafil. Exercise stress tests have been recommended, but serious adverse events have occurred in men with normal stress tests following the ingestion of sildenafil. Blood pressure monitoring following sildenafil administration will not prevent a serious adverse drug event already in progress. This article discusses the advantages and disadvantages of initiating treatment with a low test dose of sildenafil, performed at home or in the doctor's office. The advantages of this approach include: (i) identifying patients who are highly sensitive to the effects of sildenafil and who may need no higher dose; (ii) minimising adverse effects such as flushing and dizziness that often frighten patients and may affect adherence; (iii) avoidance of major adverse events; and (iv) reassuring patients with ED who remain wary about trying sildenafil therapy.
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PMID:Should patients be given an initial low test dose of sildenafil? 1091 29

Oral sildenafil is an effective treatment for erectile dysfunction (ED), which is a common complaint for patients with hypertension and those taking antihypertensive agents. This post hoc subanalysis assessed the efficacy and safety of sildenafil in men with ED who were receiving concomitant antihypertensive medication. Efficacy was assessed in 3414 men (1218 of whom were taking antihypertensive medication) who received sildenafil (5 to 200 mg) or placebo for 6 weeks to 6 months in 10 double-blind, placebo-controlled studies. The significant improvements in erectile function demonstrated by sildenafil-treated patients were comparable in patients taking and those not taking antihypertensive medication. Safety was assessed in 3975 men (1094 of whom were taking one or more antihypertensive agent, classified as a diuretic, beta-blocker, alpha1-blocker, angiotensin converting enzyme inhibitor, or calcium channel blocker), who received sildenafil or placebo in 18 double-blind, placebo-controlled studies. For patients taking sildenafil and antihypertensive medication, the incidence of treatment-related adverse events (34%) was similar to that for sildenafil-treated patients not taking any antihypertensive agent (38%). The incidences of the most common adverse events and of adverse events potentially related to blood pressure decreases (eg, hypotension, dizziness, and syncope) were similar in both sildenafil groups. The number of antihypertensive medications taken from among the five classes had no effect on the adverse event profile of sildenafil. 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:Effect of sildenafil in patients with erectile dysfunction taking antihypertensive therapy. Sildenafil Study Group. 1120 84

This paper reviews laboratory and clinical data concerning oral phentolamine mesylate, Vasomax, an alpha-1, alpha-2 adrenergic receptor antagonist developed specifically for treatment of erectile dysfunction. A contemporary view of the neurovascular mechanisms in penile erection includes the effects of both smooth muscle relaxation and contraction. Contraction of the cavernosal arteries and trabecular smooth muscle appears to be predominantly under the control of alpha-adrenergic innervation. Conversely, adrenergic blockade of alpha-1 and alpha-2 receptors has been shown to facilitate penile erection in both animal and human models. The pharmacokinetic profile of Vasomax appears well suited for an oral erectogenic agent. Vasomax is rapidly absorbed and eliminated in normal males. Peak plasma concentrations are achieved in 30-60 min, and the half-life approximates 5-7 h. Food decreases the rate, but not the extent of bioavailability. Vasomax has low protein binding and is excreted primarily via urine and feces. There is a strong dose-response relationship in maximum plasma concentration (Cmax) and area under the curve (AUC), and there are no clear age-related differences in absorption or elimination rates. Efficacy of Vasomax has been systematically evaluated in two (ZON300, ZON301) large-scale, placebo-controlled trials, in addition to two long-term open-label studies. In both studies, Vasomax was associated with significant improvements in the erectile function domain scores of the International Index of Erectile Function (IIEF). Further improvements were noted as the duration of treatment and dose level were increased. The percentage of successful penetration attempts was also significantly improved with Vasomax compared to placebo. For patients who continued in open-label treatment with Vasomax, efficacy was generally well maintained. Vasomax was well tolerated by the majority of patients. The most common side effects observed were nasal congestion (10%), headache (3%), dizziness (3%), tachycardia (3%) and nausea (1%). Side effects were generally dose-related and in the mild-to-moderate range in all three studies. Furthermore, side effects seldom resulted in treatment discontinuation. Very few serious adverse events were observed in these trials. In summary, Vasomax appears to be effective in the treatment of male erectile dysfunction and well-tolerated by the majority of patients. The drug has a satisfactory side effect profile, without significant risk of cardiovascular effects. Results of clinical trials with Vasomax support the concept of adrenergic-blockade as a clinically relevant mechanism in the control of penile erection.
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PMID:Vasomax for the treatment of male erectile dysfunction. 1128 71

The efficacy and safety of sildenafil were evaluated in a randomised, double-blind, placebo-controlled, flexible-dose study in Taiwanese men aged 26 to 80 y with erectile dysfunction (ED) of broad-spectrum aetiology and more than 6 months' duration. A total of 236 patients were randomised at six medical centres in Taiwan to receive either sildenafil (50 mg initially increased if necessary to 100 mg or decreased to 25 mg depending on efficacy and toleration) (n=119) or matching placebo (n=117) taken on an 'as needed' basis 1 h prior to anticipated sexual activity for a period of 12 weeks. At the end of 12 weeks, the primary efficacy variables relating to the achievement and maintenance of erections sufficient for sexual intercourse, and the secondary efficacy variables, which included: (1) the five separate domains of sexual functioning of the IIEF (International Index of Erectile Function) scale, (2) the percentage of successful intercourse attempts; and (3) a global assessment of erections, were all statistically significantly improved by sildenafil in comparison with placebo (P<0.0001). Treatment-related adverse events occurred in 43.7% of patients receiving sildenafil and 18.8% receiving placebo. The most common adverse events with sildenafil were flushing, dizziness and headache (25.2, 6.7 and 5.9% of patients, respectively), and most were mild in nature. The efficacy and safety of sildenafil in the population of Taiwanese men appears similar to that reported in other studies in western populations.
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PMID:ASSESS-3: a randomised, double-blind, flexible-dose clinical trial of the efficacy and safety of oral sildenafil in the treatment of men with erectile dysfunction in Taiwan. 1149 79

Sublingual (SL) apomorphine (2 to 6 mg) has been shown to be effective for treatment of male erectile dysfunction. Many patients with erectile dysfunction are also being treated for systemic hypertension and/or cardiovascular disease. In a double-blind, randomized, placebo-controlled, crossover trial, SL apomorphine 5 mg and placebo were administered on alternate days to 162 men who were on long-term therapy (> or =4 weeks) with angiotensin-converting enzyme inhibitors, beta blockers, diuretics, calcium channel blockers, alpha(1) blockers, or short- or long-acting nitrates. Blood pressure and heart rate were measured before and after dosing; cardiac rhythm was recorded by 4-hour Holter monitoring. The only potentially clinically significant interactions between SL apomorphine and the antihypertensive agents or short-acting nitrates were greater orthostatic decreases in systolic blood pressure in the alpha-blocker and calcium channel blocker groups (-10 and -6 mm Hg vs placebo, respectively). Administration of SL apomorphine after dosing with long-acting nitrates resulted in significant decreases in blood pressure when patients were standing (mean systolic change, -5 to -9 mm Hg 30 to 60 minutes postdose, p <0.05; mean diastolic change, -3 to -4 mm Hg 50 to 60 minutes postdose, p <0.05). The most common adverse events with SL apomorphine were dizziness, nausea, and headache. Syncope occurred in 1 patient in the beta-blocker group; symptomatic hypotension occurred in 2 patients each in the short- and long-acting nitrate groups. Thus, in patients receiving common antihypertensive agents and short-acting nitrates, as well as in most patients receiving long-acting nitrates, SL apomorphine at higher than recommended doses produced no clinically significant changes in heart rate or blood pressure greater than changes seen with SL apomorphine alone.
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PMID:Cardiovascular safety of sublingual apomorphine in patients on stable doses of oral antihypertensive agents and nitrates. 1158 43


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