Benign Prostatic Hyperplasia – Prostate Cancer – Prostatitis

Posts Tagged ‘Sildenafil’

Erectile Dysfunction Evaluation and Treatment

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The goals of evaluating patients with erectile dysfunction are to determine the medical and psychosexual causes, assess the degree of dysfunction, and determine treatment goals for both patient and partner. Although multifactorial erectile dysfunction is common, the patient with new onset Erectile dysfunction as a consequence of prostatectomy will be discussed here. As with all patients with erectile dysfunction, a complete psychosexual history is critical for evaluation. Focus on duration of dysfunction, level of libido, presence of morning erections, erection quality, and psychologic factors can help direct further work-up and treatment. Comorbid diseases, particularly diabetes mellitus, hypertension, smoking, vascular disease, and psychiatric illness may also contribute to Erectile dysfunction. While less likely in this group, a fair number of men will have underlying psychogenic factors contributing to their erectile dysfunction. Physical examination with attention to testicular size, gynecomastia, and body habitus, as well as a focused neurologic examination, will also aid in identification Read more [...]

Drug Interactions in the Treatment of ED, LUTS and BPH: Clinically Relevant Drug­-Drug Interactions

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Clinically Relevant Drug­-Drug Interactions With the 5-Alpha-Reductase Inhibitors Neither dutasteride nor finasteride have any clinically significant pharmacodynamic or pharmacokinetic adverse drug interactions. Studies show that the 5-alpha-reductase inhibitors do not affect the CYP 450 enzyme system. However, agents that inhibit the CYP 450 3A4 may, in theory, interfere with metabolism of these medications. Therefore, until more data are available, cautious monitoring should follow the concurrent administration of a 5-alpha-reductase inhibitor with an agent known to alter the activity of the hepatic mixed function oxidase enzyme system. Pharmacodynamic Drug-Drug Interactions With PDE-5 Inhibitors Pharmacodynamic drug interactions leading to precipitous hypotension and MI are clinically relevant with PDE-5 inhibitors. All selective inhibitors of cyclic GMP-specific PDE-5 are prone to clinically significant pharmacodynamic interactions with agents that produce vasodilation. The concurrent use of nitrate preparations is a contraindication to treatment with selective inhibitors of cyclic GMP-specific Read more [...]

Drug Interactions in the Treatment of ED, LUTS and BPH: Clinically Significant Drug­-Drug Interaction

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The English-language medical literature, from 1986 to the present, was searched via the computer-based Medline system of the National Library of Medicine. The search focused on drug interaction data for the following agents: alfuzosin, doxazosin, dutasteride, finasteride, sildenafil, tamsulosin, tadalafil, terazosin, and vardenafil. Data were limited to information derived from studies of human subjects or actual patients and included premarketing and postmarketing observations. Articles reviewed included original studies, meta-analyses, and systematic reviews. Drug interactions were grouped into either pharmacodynamic interaction or pharmacokinetic interaction based on the mechanism. Pharmacodynamic Drug­-Drug Interactions With Selective Alpha-1-Adrenergic Receptor Blockers As a class, these agents potentiate hypotension when given concurrently with other antihypertensive agents. However, tamsulosin and alfuzosin do not cause a greater hypotensive effect when given concurrently with antihypertensive agents because tamsulosin and alfuzosin are highly selective for alpha-1-adrenergic receptors Read more [...]

Drug Interactions in the Treatment of ED, LUTS and BPH: Selective Cyclic GMP-Specific PDE-5 Inhibitors

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Pharmacodynamics PDE-5 inhibitors are indicated for the treatment of erectile dysfunction (ED). The physiological mechanism of penile erections involves the release of nitric oxide (NO) during sexual stimulation. Nnitric oxide activates guanylate cyclase to release copious amounts of cyclic guanosine monophosphate (GMP). Subsequently, nitric oxide and cyclic GMP cause the smooth muscle of the corpus cavernosum to relax, and as the corpus cavernosum fills with blood, the penis becomes erect. Unfortunately, the cause of erectile dysfunction in many patients is an imbalance between contraction and relaxation of the smooth muscle of the corpus cavernosum. Competitive inhibition of PDE-5 enzymes increases the intracellular stores of cyclic guanosine monophosphate and enhances the vasodilatory effects of nitric oxide. Subsequently, cyclic GMP relaxes corpus cavernosal smooth muscle cells and increases blood flow into cavernosal spaces. These changes enhance blood flow into the corpus cavernosum and increase intracavernosal pressure to produce a firm erection during sexual stimulation. Pharmacokinetics PDE-5 Read more [...]