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)

Treatment with antidepressants, especially agents with potent serotonergic effects, is frequently associated with sexual side effects. In the present study, we examined the efficacy of sildenafil, a potent phosphodiesterase inhibitor, in the treatment of elderly men (n = 10; 70-81 years) with erectile dysfunction induced by antidepressant treatment for major depressive disorder. Eligible subjects were instructed to add sildenafil (25-50 mg/day) to their current drug treatment. Clinical assessment of erectile function was performed at beginning of treatment with sildenafil and at follow up, 4 weeks later. All patients reported an improvement of their erectile capacity, and in 7 out of 10 subjects, erectile function returned to a normal level. Sildenafil appears to be a safe and well-tolerated agent in elderly subjects. We noted side effects in 2 patients (flashes), but the side-effects were bothersome only to one patient (headache). It appears that sildenafil coadministration improves erectile dysfunction associated with selective serotonin reuptake inhibitor ongoing treatment in elderly patients.
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PMID:Sildenafil for selective serotonin reuptake inhibitor-induced erectile dysfunction in elderly male depressed patients. 1450 18

Advances in molecular biology and protein chemistry, along with increasing understanding of the mechanisms of penile erection, have spurred development of pharmacologic approaches to the treatment of erectile dysfunction (ED). The next generation of oral agents includes tadalafil, a potent, highly selective phosphodiesterase 5 inhibitor. In vitro studies have shown that tadalafil enhances relaxation of trabecular smooth muscle, and clinical trials have supported its efficacy and tolerability in a broad population of men with ED. The effect of tadalafil in enhancing the erectile response to sexual stimulation is relatively rapid in onset and lasts for >or=24 hours. The ability of patients with ED treated with tadalafil to achieve improved erectile function is demonstrated by significantly increased subjective measures of penetration ability, successful intercourse, and sexual satisfaction. Partners have expressed similar or higher levels of satisfaction with the results of treatment. Men with ED of psychogenic, organic, or mixed etiology and in a range from mild to severe have experienced significant improvment with tadalafil treatment. Response to treatment in men with diabetes has been robust and not affected by disease severity. Tadalafil has been well tolerated. Adverse events have generally been mild or moderate and have abated with continued treatment. Headache and dyspepsia have been most frequently reported. Changes in color vision have been rare (<0.1%) with tadalafil across all clinical trials. Tadalafil appears to be a safe and effective treatment for men with ED.
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PMID:Efficacy and tolerability of tadalafil, a novel phosphodiesterase 5 inhibitor, in treatment of erectile dysfunction. 1460 20

Vardenafil is a phosphodiesterase type-5 (PDE-5) inhibitor developed as an oral therapy for erectile dysfunction (ED). Multiple phase 3 clinical trials have been completed and vardenafil is expected to launch worldwide in 2003. Two pivotal, randomized, double-blind, multicenter studies have evaluated the use of vardenafil in men with ED. Vardenafil improved the rate of achieving and maintaining an erection during sexual intercourse. Improvement also was noted in other aspects of sexual function, including confidence, orgasmic function, and overall satisfaction. Vardenafil produces clinically and statistically significant improvements in erectile function regardless of age, baseline severity, and etiology and is efficacious for the treatment of ED in diabetic and postprostatectomy patients. Vardenafil has a rapid onset of action and completion of successful sexual intercourse is possible for some patients 16 minutes after its administration. Twenty milligrams of vardenafil has sustained long-term efficacy by providing up to 92% of patients with improved erections during more than 2 years of treatment. Vardenafil is well tolerated, with an adverse event profile typical of the class of PDE-5 inhibitors. The most common adverse events were headache, flushing, rhinitis, and dyspepsia, which were mild or moderate and generally decreased with continued treatment. Vardenafil may be associated with transient reductions in blood pressure and commensurate increases in heart rate, with the overall incidence of cardiovascular-related adverse events similar to that of placebo.
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PMID:Vardenafil: a new approach to the treatment of erectile dysfunction. 1462 2

Vardenafil (Levitra), recently launched in Belgium by Bayer and Glaxo-SmithKline, is a new drug that potently and selectively inhibits phosphodiesterase type 5 (PDE5) in the cavernosum tissue of the penis. Inhibition of PDE5 blocks the hydrolysis of cyclic guanosine monophosphate (GMPc) and results in increased arterial blood flow leading to enlargement of the corpus cavernosum and resulting in erection. In controlled clinical trials, vardenafil at least doubled the rate of successful erections as compared to placebo, whatever the evaluation parameter considered and the subgroup of patients studied. Vardenafil is thus indicated in the treatment of patients with erectile dysfunction. It is presented as 5, 10 and 20 mg tablets and the usual dose is 10 mg to be ingested 25 to 60 minutes before sexual activity. Vardenafil has a more potent inhibitory activity of PDE5 in vitro than sildenafil or tadalafil while its pharmacokinetics in vivo is somewhat more rapid than that of the two other compounds. The dosage of vardenafil may be reduced to 5 mg (especially in older individuals) to improve tolerance or be increased up to 20 mg (especially in the presence of organic diseases aggravating erectile dysfunction) to improve efficacy. Contra-indications (co-administration with drugs increasing nitric oxide) and side-effects (headache and flushing due to vasodilatation) of vardenafil are similar to those of other PDE5 inhibitors.
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PMID:[Medication of the month. Vardenafil (Levitra)]. 1462 53

Orally administered phosphodiesterase type 5 (PDE5) inhibitors have become the first-line treatment option for erectile dysfunction (ED). Vardenafil is a potent and highly selective PDE5 inhibitor developed as an oral therapy for ED. Two pivotal, randomised, double-blind, multi-centre studies have evaluated the use of vardenafil in men with ED. Vardenafil improved the rate of achieving and maintaining an erection during sexual intercourse. Improvement was also noted in other aspects of sexual function, including confidence, orgasmic function and overall satisfaction. Vardenafil produces clinically and statistically significant improvements in erectile function regardless of age, baseline severity and aetiology and is efficacious for the treatment of ED in diabetic and postradical prostatectomy patients. Vardenafil has a rapid onset of action, in which erections sufficiently rigid for eventual intercourse completion can be achieved as early as 16 min after ingestion. Vardenafil 20 mg has sustained long-term efficacy by providing up to 92% of patients with improved erections during > 2 years of treatment. Vardenafil is well-tolerated, with an adverse event profile typical of this class of PDE5 inhibitors. The most common adverse events were headache, flushing, rhinitis and dyspepsia, which were mild-to-moderate in severity and they generally attenuated with continued use. Vardenafil may be associated with transient reductions in blood pressure and commensurate increases in heart rate, with the overall incidence of cardiovascular-related adverse events similar to that of placebo. Although claims can be made about potential features of benefit for each of the currently marketed PDE5 inhibitors, there are at present, no non-pharmaceutical company sponsored, peer-reviewed, head-to-head trials that have been published.
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PMID:Vardenafil: a novel type 5 phosphodiesterase inhibitor for the treatment of erectile dysfunction. 1510 74

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.
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PMID:Phosphodiesterase type 5 inhibitor differentiation based on selectivity, pharmacokinetic, and efficacy profiles. 1511 91

Pharmacotherapy is limited for the relief of intermittent claudication (IC), a common manifestation of peripheral arterial disease (PAD). Pentoxyfylline, the only current pharmacological therapy for IC, has been shown to have similar efficacy as placebo. Cilostazol, a new phosphodiesterase III (PDE III) inhibitor, is a potent inhibitor of platelet aggregation with vasodilatory, antithrombotic, antiproliferative and positive lipid-altering effects. To evaluate the efficacy and safety of cilostazol for the treatment of IC in Indian patients, 123 patients were selected from 6 centres in India. The patients, aged 58-73 years, with the diagnosis of stable moderate-to-severe IC received cilostazol 100/50 mg twice daily for a period of 12 weeks. Primary efficacy measures included initial claudication distance (ICD) and absolute walking distance (ACD) by treadmill testing and ankle-brachial index (ABI) using Doppler ultrasonography-measured systolic pressures. Secondary efficacy outcomes included subjective assessment of symptom improvement by patient and investigator and estimation of lipid values. Adverse events were monitored throughout the study. Laboratory investigations were carried out at baseline and end of study. At the end of week 12 of cilostazol therapy, there was a significant improvement in the raw walking distances (ICD and ACD). Percentage change in ICD and ACD was 46.77% and 64.5%, respectively, at the end of study. There was a significant increase (32.7%) in the ABI by the end of study period. According to patient and investigator assessment of symptoms, 58-60% of the subjects showed significant improvement to complete resolution of claudication symptoms by the end of 12 weeks of therapy. In addition, there was a significant increase of 20.24% in the mean plasma HDL-cholesterol levels and a decrease of 29.55% in the mean plasma triglyceride concentrations by the end of study period. Headache, diarrhoea, palpitation and dizziness were the commonly reported adverse effects during the study. No adverse effect led to discontinuation of therapy. The present study suggests that cilostazol is an effective therapeutic option with an acceptable tolerability profile for the treatment of IC in patients with PAD.
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PMID:Efficacy and safety of cilostazol, a novel phosphodiesterase inhibitor in patients with intermittent claudication. 1516 99

Vardenafil potently inhibits human phosphodiesterase 5 (PDE5) with an IC50 of 0.7 nM. Enhancement of nitric oxide (NO)-induced erections in rabbits by 0.1 mg/kg vardenafil is limited by its pharmacokinetic properties (Tmax=1 h; T1/2=1.2 h), although erectile effects have been observed after 7 h. In humans, vardenafil is rapidly absorbed (Tmax approximately 40 min) and more slowly metabolized (T1/2 approximately 4 h), with an absolute bioavailability of 14.5% (vs 40% for sildenafil). Although the consumption of high-fat meals does not affect the drug's relative bioavailability, it retards intestinal absorption. Coadministration of CYP3A4 inhibitors such as ritonavir can affect hepatic metabolism. M1, an active metabolite of vardenafil, is a four-fold-less potent inhibitor of PDE5 than its parent compound, contributing approximately 7% to vardenafil's overall efficacy. The side effects of all selective PDE5 inhibitors commonly include vasodilation, small reductions in blood pressure, headache, and nasal congestion.
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PMID:Vardenafil preclinical trial data: potency, pharmacodynamics, pharmacokinetics, and adverse events. 1522 34

Sildenafil revolutionised the treatment of erectile dysfunction (ED) on its introduction in 1998. Not only is it effective, but is, perhaps even more importantly, an extremely acceptable manner in which to treat ED (i.e., oral pharmacotherapy), compared to the other treatments that were available at that time (e.g., intracavernosal injection). Whilst sildenafil remains the market leader for ED treatment, it does have some shortcomings: its clinical efficacy is diminished in 'difficult to treat' patient groups, such as diabetics, side effects, such as blue-tinged vision and headache, and the need to time the ingestion of sildenafil to 1 h prior to expected time of sexual intercourse. Recently, newer phosphodiesterase inhibitors ('sons of viagra') have become available, and potentially to improve upon, what has become regarded as the gold standard for ED treatment. This review article discusses the differences between vardenafil, tadalafil and sildenafil, in order to allow the clinician to make an informed decision as to which phosphodiesterase inhibitor to prescribe when dealing with the ever expanding number of patients seeking help for ED.
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PMID:New phosphodiesterase inhibitors in the treatment of erectile dysfunction. 1550 Mar 70

Erection is a neurovascular event that involves spinal and supra spinal pathways. The final common pathway involves the release of nitric oxide (NO) from both endothelial cells and neurons, which acts as a vasodilator causing penile engorgement and erection. NO is degraded by the enzyme phosphodiesterase (PDE) type 5 in the penis. Erectile dysfunction (ED), defined as the persistent inability to achieve and/or maintain an erection sufficient for satisfactory sexual performance, results when the neurovascular pathway is interrupted by medical conditions or drugs. A 15-item self-administered questionnaire, the International Index of Erectile Function (IIEF), is one of the most useful tools to evaluate erectile function (EF) in clinical trials, although of much less use in routine clinical practice. The MMAS (Massachusetts Male Aging Study) was the first major epidemiological investigation to study the prevalence of ED. The study found that ED was three times more common in patients with diabetes mellitus. The aetiopathogenesis of ED in diabetes is multifactorial, with vascular and neural factors being equally implicated. Hyperglycaemia is believed to give rise to biochemical perturbations that lead to these microvascular changes. In the MMAS, ED in diabetes was strongly correlated with glycaemic control, duration of disease and diabetic complications. The incidence increased with increasing age, duration of diabetes and deteriorating metabolic control, and was higher in individuals with type 2 diabetes than those with type 1.ED in men with diabetes often affects their quality of life and, as patients are often reluctant to come forward with their symptoms, a carefully taken history is one of the most useful approaches in identifying affected individuals. The PDE inhibitors have revolutionised the management of ED and oral drug therapy is currently first-line therapy for the condition. These agents act by potentiating the action of intracavernosal NO, thereby leading to a more sustained erection. Sildenafil was the first PDE5 inhibitor to undergo evaluation and has been studied extensively. More recently two other agents, vardenafil and tadalafil, have been introduced. All the drugs have been shown to be effective across a wide range of aetiologies of ED, including diabetes. The drugs have been shown to improve EF domain scores, penetration and maintenance of erection, resulting in more successful intercourse. Their effects are greater at higher doses. Sildenafil and vardenafil are shorter-acting agents, while tadalafil has a longer half-life allowing the user more flexibility in sexual activity. Common adverse effects include headache, nasal congestion and dyspepsia, all actions related to inhibition of PDE5. The drugs are generally well tolerated and withdrawal from the clinical studies as a result of drug-related adverse effects were rare. The use of PDE5 inhibitors in the presence of oral nitrates is absolutely contraindicated. The clinical studies to date have not evaluated the use of one drug in the case of treatment failure with another agent. Sublingual apomorphine, which stimulates central neurogenic pathways, is a new agent and may be a suitable alternative in those patients in whom PDE5 inhibitors are ineffective or contraindicated. In clinical trials, all IIEF domains except sexual desire were found to have improved after apomorphine. The median times to erection in these studies were 18.9 and 18.8 minutes for the 2 and 3mg doses, respectively. Intraurethral and intracavernosal alprostadil may be a useful alternative when oral drug therapy is ineffective or contraindicated. The management of ED in the diabetic patient may often involve a multidisciplinary approach where psychosexual counselling and specialist urologist advice is required in addition to the skills and expertise of the diabetologist. Finally, the introduction of the new oral agents have completely revolutionised the management of ED and allowed more individuals to come forward for treatment.
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PMID:New treatment options for erectile dysfunction in patients with diabetes mellitus. 1553 69


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