Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Understanding the mechanism of action and the pharmacokinetic properties of vasodilatory drugs facilitates optimal use in clinical practice. It should be kept in mind that a drug belongs to a class but is a distinct entity, sometimes derived from a prototype to achieve a specific effect. The most common pharmacokinetic drug improvement is the development of a drug with a half-life sufficiently long to allow an adequate once-daily dosage. Developing a controlled release preparation can increase the apparent half-life of a drug. Altering the molecular structure may also increase the half-life of a prototype drug. Another desirable improvement is increasing the specificity of a drug, which may result in fewer adverse effects, or more efficacy at the target site. This is especially important for vasodilatory drugs which may be administered over decades for the treatment of hypertension, which usually does not interfere with subjective well-being. Compliance is greatly increased with once-daily dosing. Vasodilatory agents cause relaxation by either a decrease in cytoplasmic calcium, an increase in nitric oxide (NO) or by inhibiting myosin light chain kinase. They are divided into 9 classes: calcium antagonists, potassium channel openers, ACE inhibitors, angiotensin-II receptor antagonists, alpha-adrenergic and imidazole receptor antagonists, beta 1-adrenergic agonist, phosphodiesterase inhibitors, eicosanoids and NO donors. Despite chemical differences, the pharmacokinetic properties of calcium antagonists are similar. Absorption from the gastrointestinal tract is high, with all substances undergoing considerable first-pass metabolism by the liver, resulting in low bioavailability and pronounced individual variation in pharmacokinetics. Renal impairment has little effect on pharmacokinetics since renal elimination of these agents is minimal. Except for the newer drugs of the dihydropyridine type, amlodipine, felodipine, isradipine, nilvadipine, nisoldipine and nitrendipine, the half-life of calcium antagonists is short. Maintaining an effective drug concentration for the remainder of these agents requires multiple daily dosing, in some cases even with controlled release formulations. However, a coat-core preparation of nifedipine has been developed to allow once-daily administration. Adverse effects are directly correlated to the potency of the individual calcium antagonists. Treatment with the potassium channel opener minoxidil is reserved for patients with moderately severe to severe hypertension which is refractory to other treatment. Diazoxide and hydralazine are chiefly used to treat severe hypertensive emergencies, primary pulmonary and malignant hypertension and in severe preeclampsia. ACE inhibitors prevent conversion of angiotensin-I to angiotensin-II and are most effective when renin production is increased. Since ACE is identical to kininase-II, which inactivates the potent endogenous vasodilator bradykinin, ACE inhibition causes a reduction in bradykinin degradation. ACE inhibitors exert cardioprotective and cardioreparative effects by preventing and reversing cardiac fibrosis and ventricular hypertrophy in animal models. The predominant elimination pathway of most ACE inhibitors is via renal excretion. Therefore, renal impairment is associated with reduced elimination and a dosage reduction of 25 to 50% is recommended in patients with moderate to severe renal impairment. Separating angiotensin-II inhibition from bradykinin potentiation has been the goal in developing angiotensin-II receptor antagonists. The incidence of adverse effects of such an agent, losartan, is comparable to that encountered with placebo treatment, and the troublesome cough associated with ACE inhibitors is absent.
 ...
PMID:Clinical pharmacokinetics of vasodilators. Part I. 964 8

A phosphodiesterase inhibitor (PDEI), Ibudilast, which has been in wide use for the management of bronchial asthma and cerebrovascular disease in Japan, was tested for its clinical efficacy on experimental autoimmune encephalomyelitis (EAE) in Dark August rats. The severity of acute EAE was significantly ameliorated by prophylactic oral treatment with Ibudilast (10 mg/kg per day) starting on the day of immunization, although it did not modify the course of the disease when it was given after the onset of the first clinical sign of EAE. Histologically, inflammatory cell infiltration in the lumbar spinal cord was significantly reduced in Ibudilast-treated animals as compared to control animals. Ibudilast mildly suppressed MBP-induced proliferation of T cells in regional lymph nodes, the secretion of interferon-gamma from T cells activated by MBP in CFA, and the secretion of tumor necrosis factor-alpha from macrophages. While the in vitro studies did not suggest difference between Ibudilast and other PDEIs such as rolipram, the clinical dose of Ibudilast is approximately 200-fold higher than that of rolipram and the effective dose of Ibudilast was relatively close to what has been therapeutically used in patients. Thus, Ibudilast may be a candidate for clinical use for patients with multiple sclerosis. 1999 Elsevier Science B.V. All rights reserved.
 ...
PMID:Ibudilast, a phosphodiesterase inhibitor, ameliorates experimental autoimmune encephalomyelitis in Dark August rats. 1022 13

Optimal treatment of patients with atopic dermatitis requires the knowledge of its pathogenetic factors and the often time-consuming attention to the course of the disease in each individual patient. In the therapeutic attempt, altered skin barrier function, possible provocation factors and psychological matters have to be taken into account. Basic therapy should comprise optimal skin care and the strict avoidance of triggering factors if possible. During periods of acute exacerbation, topical glucocorticosteroids in combination with classic antihistamines with sedative effects are still the drugs of first choice and will result in the rapid relief of symptoms in most patients. UVA1 phototherapy has proven to be a glucocorticoid-equivalent alternative therapy for exacerbated atopic dermatitis. If superinfection with Staphylococcus aureus is evident, topical antiseptics are useful in treating localized lesions, while a general superinfected eczema should be treated with systemic staphylococcal-effective antibacterials. Cyclosporin or extracorporeal photochemotherapy are reserved for patients with very severe atopic dermatitis that is unresponsive to conventional treatment protocols. Promising future therapeutic approaches consist of an improvement in the antipruritic treatment options, the topical application of immunomodifying treatment modalities or phosphodiesterase inhibitors, and possibly Chinese herbal therapies and psychological intervention strategies.
 ...
PMID:Optimal management of atopic dermatitis. 1170 4

The identification of several mutations of the bone morphogenetic protein receptor 2 (BMPR2) gene, a member of the transforming growth factor beta receptor family, gives hope for new insights into the pathophysiology of pulmonary hypertension. Genetic predisposition might dictate the responses of pulmonary artery fibroblasts, smooth muscle cells, and endothelial cells, as well as platelets and leukocytes, or their specific interactions with different extrinsic factors. These cells possess distinct subtypes and interact with each other. Pulmonary hypertension is associated with vasoconstriction, remodeling, and in situ thrombosis of the pulmonary arteries, but the initial events and their relationship to the genetic background are presently unknown. Current therapeutic approaches are based on our knowledge of the physiologic regulation of pulmonary artery tone, pathophysiologic changes, and our clinical experience with different treatment strategies. Beyond diuretics and anticoagulants, prostaglandins are generally accepted therapeutic agents for primary pulmonary hypertension and related diseases, whereas high-dose calcium-channel blockers are reserved for a small subset of patients, those who respond favorably to vasodilators in an acute test. Long-term intravenous prostacyclin infusion has become the most important specific therapy for primary pulmonary hypertension and associated diseases. However, this therapy is hampered by catheter complications and systemic side effects. Alternative application routes of prostacyclin or its stable analogs may avoid these problems. Inhaled application of the prostacyclin analog iloprost results in predominant pulmonary vasodilation with few systemic side effects and may possess clinical efficacy similar to that of intravenous prostacyclin. Inhaled nitric oxide is widely accepted as a screening agent for active responders to vasodilators and has a similar hemodynamic profile as inhaled iloprost, although the percentage of responders is considerably lower. However, there are unsolved toxicologic questions and practical difficulties concerning the safe long-term application of nitric oxide. Combining inhaled vasodilators with phosphodiesterase inhibitors may prolong the duration of the effects and improve the convenience of inhaled therapy for pulmonary hypertension. Therapeutic approaches in the future may aim at the transforming growth factor beta pathway and at the identification of early stages of the disease to prevent further disease progression.
 ...
PMID:Cellular pathophysiology and therapy of pulmonary hypertension. 1175 83

Hospital admissions for acute decompensated heart failure (ADHF) have increased precipitously during the past few decades and are projected to continue to increase in the future. To optimize patient outcomes and reduce the costs associated with this disorder, evidenced-based pharmacotherapy is essential. Continuous infusions of loop diuretic therapy rather than bolus dosing may enhance efficacy and reduce the extent of diuretic resistance. Nesiritide is a pharmacologically novel preload and afterload reducer but based on clinical trial evidence should be reserved for those unable to take or with resistance to intravenous nitrate therapy. Catecholamine- and phosphodiesterase-based inotropic therapies are efficacious, but the increased risk of arrhythmogenesis and the potential for negative survival effects limit their use. The experimental agent levosimendan is a positive inotropic agent but does not increase myocyte calcium concentrations as do catecholamines or phosphodiesterase inhibitors. Clinical trial evidence demonstrates a positive survival benefit for levosimendan versus dobutamine.
 ...
PMID:Acute decompensated heart failure: a contemporary approach to pharmacotherapeutic management. 1292 Dec 47

The aim of this Core Document of the Spanish Consensus on Erectile dysfunction (ED) is to offer guidance to the nonspecialist physician in the management of patients with ED. ED is one of the most frequent chronic health problems in men older than 40 y of age and may also act as a sentinel symptom for other important underlying diseases. Its etiology can be classified into organic, psychogenic, or mixed. In most cases, the underlying cause of ED is usually a chronic health problem (such as diabetes, hypertension, atherosclerosis, and so on) or an adverse drug effect. The initial step in the management is to assess erectile function in patients with risk factors for ED. Once ED has been established, a detailed sexual, medical, and social history, including a review of medications used, is the most important aspect of a patient's assessment. Generally, examination should be limited to the cardiovascular, neurological, and urogenital systems. Fasting glucose and blood lipid profile should be performed in every man with ED, and free testosterone levels in men older than 50 y or if hypogonadism is suspected; other diagnostic tests are optional and should be requested on an individualized basis. In many cases, the most likely cause of ED can be identified based on the above information. Therapeutic intervention should be patient-oriented and based on the expectations and wishes of the patient and his partner, who should be included in discussions whenever possible. Basic interventions common to any type of ED include sexual counseling, lifestyle modifications, treatment of associated medical conditions, and switching to alternative drugs with lower risk of ED. In certain cases, an etiologic treatment may be performed (sex therapy, revascularization surgery, and hormonal therapy). Most patients with ED will benefit from symptomatic treatments; first-line therapy may be prescribed by physicians who are not specialists in ED, and includes oral agents such as inhibitors of phosphodiesterase type 5, currently considered the drugs of choice for initial treatment of ED. Intracavernous drugs are the second-line therapy, and surgical treatments, such as implantation of penile prostheses, are reserved for urologists/andrologists who specialize in ED. Referral may be appropriate where indicated by age, clinical findings, or the patient's request.
 ...
PMID:Core document on erectile dysfunction: key aspects in the care of a patient with erectile dysfunction. 1549 54

According to preliminary studies, the overall incidence of spinal cord injury (SCI; traumatic and medical) in Spain is estimated to be between 12 and 20 per million inhabitants, and almost 80% of these injuries occur in young men. SCI causes organic changes in men leading to erectile dysfunction (ED), impaired ejaculation, and changes in genital orgasmic perception. A vast majority of men with both complete and incomplete SCI will require treatment for ED, and the therapeutic options should include sexual counseling so that the patient can be informed about his disorder and can adjust his sexual behavior accordingly. The first-line treatment of choice is oral drugs, such as phosphodiesterase inhibitors (sildenafil, tadalafil, and vardenafil). Sildenafil has been shown to be highly effective and well tolerated in men with ED of various etiologies, including SCI. Data are also presented on sublingual apomorphine, which has limited indications for the treatment of ED in SCI, and on constrictive rings and vacuum systems. Second-line treatments include intracavernous injections of prostaglandin E(1), papaverine, and phentolamine, alone or in combination, which have been shown to be highly effective in the treatment of ED in men with SCI. Finally, for third-line treatments, the indications for surgical methods are given, including penile prostheses and neuroprosthesis of anterior sacral roots. These devices should be reserved for the cases when the above-mentioned methods have repeatedly failed. Historically, the treatment of ED among patients with SCI has been managed by clinicians in physical medicine and rehabilitation. Thus, the criteria for referral and the competencies of these specialists are established, and they should be included as an integral part of the rehabilitation program.
 ...
PMID:Specific aspects of erectile dysfunction in spinal cord injury. 1549 57

Pulmonary hypertertension (PHT) is a rare disease defined by increased resistance of the pulmonary arteries inevitably leading to right heart failure if specific treatment is not given. This disease can occur sporadically (idiopathic or primary PHT), within a familial context (familial PHT, BMPR2 gene mutation), or occur as a complication of other diseases (connective tissue disease, congenital cardiomyopathy, human immunodeficiency virus infection, portal hypertension, use of anorexigenic agents). The incidence of primary PHT is 2 million cases per year, probably an underestimation due to the low specificity of clinical signs, predominantly exercise-induced dyspnea. Recent therapeutic advances (prostacyclin and endothelin receptor antagonists administered in continuous infusion) have improved the prognosis of this orphan disease. Inhaled iloprost and type 5 phosphodiesterase inhibitors should be evaluated for this indication. Lung transplantation is reserved for patients unresponsive to medical treatment.
 ...
PMID:[Pulmonary hypertension: from genetics to treatments]. 1554 47

Chronic obstructive pulmonary disease represents a major global health care burden for both primary and secondary care providers and is the most common respiratory condition necessitating hospital admission. Short-acting bronchodilators play a vital role in immediate relief of symptoms, while inhaled long-acting bronchodilators and inhaled corticosteroids are advocated for regular use in individuals with persistent symptoms and exacerbations. Theophylline is a nonspecific phosphodiesterase inhibitor and is usually reserved for patients with ongoing symptoms despite optimum inhaled bronchodilator treatment or when difficulty is encountered with inhaler devices. However, it is often not widely used mainly due to frequency of dose-related adverse effects, numerous drug interactions and narrow therapeutic index. This in turn has lead to the development of more selective phosphodiesterase inhibitors in an attempt to create a drug which patients can use with beneficial effects but without the problems associated with theophylline. Current data do indicate that phosphodiesterase 4 inhibitors confer some benefits in chronic obstructive pulmonary disease when compared to placebo in terms of lung function, quality of life and exacerbations. They are also generally well tolerated. Further studies are required to determine fully their long-term beneficial and adverse effect profiles and ultimately where they might comfortably sit in management algorithms.
 ...
PMID:Phosphodiesterase 4 inhibitors in chronic obstructive pulmonary disease: a new approach to oral treatment. 1834 75

Peyronie's disease (PD) is a fibrotic disorder of the tunica albuginea of the penis. It is characterized by different degrees of penile curvature and sexual dysfunction. Several medical treatments have been employed to manage the disorder, with variable success rates. Surgical therapy is reserved for patients with severe penile deformity that fails to improve with medical treatment and impedes coital function. The advantages and disadvantages of various surgical approaches have long been debated. Herein, we describe the evolving surgical techniques for PD using knowledge obtained from the contemporary literature. In addition, we discuss the emerging data regarding the role of phosphodiesterase 5 inhibitors in the management of PD.
 ...
PMID:Peyronie's disease: evolving surgical management and the role of phosphodiesterase 5 inhibitors. 1973 58


1 2 Next >>