Sildenafil efficacy

Gresser U, Gleiter CH. Erectile dysfunction comparison of efficacy and side effects of the PDE-5 inhibitors sildenafil, vardenafil and tadalafil review of the literature. Eur J Med Res 2002 7 435-446. 

Renal function impairment In volunteers with severe renal impairment (Ccr 30 mL/min or less), sildenafil clearance was reduced. Consider an initial sildenafil dose of 25 mg in these patients. There is no clinical data on the safety or efficacy of vardenafil in patients with end-stage renal disease requiring dialysis. 

The safety and efficacy of combinations of sildenafil or vardenafil with other treatments for erectile dysfunction have not been studied. Therefore, the use of such combinations is not recommended. 

This book describes the efficacy of Shing Jing in male fertility and erectile dysfunction and compares its efficacy with those brought about by levodopa, amylnitrite, vitamin E, and sildenafil (Viagra). 

Its impact on erectile dysfunction was discovered as a side effect in the clinical trials for angina efficacy. Because sildenafil s target was unknown, Pfizer spent additional time researching the biological processes behind sildenafil s erectile dysfunction activity. This research explains the gap between the original synthesis of sildenafil and its advancement to a commercial process. 

Pulmonary hypertension is a devastating, potentially fatal disorder. Recent years have witnessed a great expansion in our understanding of the molecular pathophysiology of this condition. Options for therapy have just become available in recent years, focused either on the prostacyclin pathway or the nitric oxide pathway for pulmonary arteriolar relaxation. Continuous infusion of prostacyclin has been successful, demonstrating the relevance of the former pathway. The efficacy of both inhaled nitric oxide and systemic sildenafil support the latter. In the future, gene transfer could be used for sustained delivery of either of these agents, by means of... 

Tadalafil has also been extensively evaluated in patients with cardiovascular disease and has a similar safety and efficacy profile to sildenafil (45). Studies have shown no adverse effects on cardiac contraction, ventricular repolarization, or ischemic threshold. A similar hypotensive effect has been recorded with a dose of doxazosin 8 mg so caution is needed. As hypotension does not occur in the supine position and as tadalafil has a long half-life it is suggested that tadalafil is taken in the morning and doxazosin in the evening. There is no interaction of tadalafil with the selective a-adrenoceptor antagonist tamsulosin, which can, therefore, be prescribed as an alternative to doxazosin for symptomatic benign prostate hypertrophy (46). 

Padma-Nathan H (ed). Sildenafil citrate (Viagra) and erectile dysfunction a comprehensive four year update on efficacy, safety, and management approaches. Urology 2002 60(2B) 1-90. 

Another recent example is provided by the discovery of the use of sildenafil (Viagra Fig. 1.15), a phosphodiesterase type 5 (PDE5) inhibitor, as an efficacious, orally active agent for the treatment of erectile dysfunction [25,26]. Initially, this compound was brought to the clinic as an hypotensive and cardiotonic substance, but its usefulness in erectile dysfunction resulted unexpectedly from clinical observations made during a 10-day toleration study in Wales [27]. 

CIMETIDINE PHOSPHODIESTERASE TYPE 5 INHIBITORS -SILDENAFIL t efficacy and adverse effects of sildenafil Inhibition of metabolism via CYP3A4 Consider a starting dose of 25 mg of sildenafil... 

PHOSPHODIESTERASE TYPE 5 INHIBITORS (e.g. sildenafil, tadalafil, vardenafil) GRAPEFRUIT JUICE Possibly t efficacy and t adverse effects, e.g. hypotension Small t in bioavailability, t variability in pharmacokinetics, i.e. interindividual variations in metabolism Safest to advise against intake of grapefruit juice for at least 48 hours prior to intending to take any of these preparations. When necessaiy, the starting dose of sildenafil should not exceed 25-50 mg and that of tadalafil 10 mg. Avoid co-administration with vardenafil... 

El-Galley R, Rutland H, Talk R, Keane T, Clark H. Longterm efficacy of sildenafil and tachyphylaxis effect. J Urol 2001 166(3) 927-31. 

The guidelines for management of erectile dysfunction issued by the F irst International Consultation on Erectile Dysfunction recommends involving the patient in selecting the treatment of his preference after explaining the benefits, risks, and costs involved with each treatment option (124). The non-inva-siveness and convenience of oral medication makes it the first choice by the vast majority of patients unless contraindicated. Sildenafil is currently the most prescribed treatment for erectile dysfunction. It is effective as a single dose and is recommended to be taken approximately 1 h before sexual activity, but can be taken anywhere from 30 min to 4 h before sexual activity. The overall efficacy of sildenafil, defined as percentage of successful attempts at sexual intercourse, is approximately 70% (125). 

Jarow JP, Burnett AL, Geringer AM. Clinical efficacy of sildenafil citrate based on etiology and response to prior treatment. J Urol 1999 162 722-725. 

Carson CC, Burnett AL, Levine LA, et al. The efficacy of sildenafil citrate (Viagra) in clinical populations An update. J Urol 2002 60(Suppl 2B) 12-27. 

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