Sildenafil citrate (Viagra) treatment for erectile dysfunction: an updated profile of response and effectiveness

Abstract

In the 7 years since sildenafil citrate (VIAGRA) was introduced as the first oral phosphodiesterase type 5 inhibitor therapy for erectile dysfunction, it has been used to treat nearly 27 million men with erectile dysfunction worldwide. Patient populations with erectile dysfunction of varying etiologies and with diverse comorbidities have benefited from sildenafil treatment. This update focuses on relatively recent research that further defines the response and effectiveness profiles of sildenafil and provides additional insight into optimizing treatment. In addition to providing recent data on sildenafil efficacy and safety/tolerability, the update provides data on assessments of erection hardness, measures of psychosocial outcomes (e.g., emotional well-being and treatment satisfaction), and treatment approaches to maximize response and effectiveness (e.g., by titrating to the maximum tolerated dose). Increased understanding of the sildenafil response and effectiveness profiles and optimal sildenafil treatment are central to the appropriate management of erectile dysfunction using sildenafil.

Multiple Affinity States of cGMP-Specific Phosphodiesterase for Sildenafil Inhibition Defined by cGMP-Dependent and cGMP-Independent Mechanisms

“…Because approval of sildenafil as an oral drug for the treatment of erectile dysfunction in 1998, many pharmacokinetic and efficacy data for this compound have been accumulated (Nichols et al, 2002;Padma-Nathan, 2006). For example, the maximum concentration of sildenafil in plasma is achieved by 1 h, and the elimination half-life is 3.7 h. Therefore, the optimal time of therapeutic use has been recommended to be between 30 min and no longer than 4 h. This drug is removed from the plasma mostly through liver metabolism, and by 24 h, its plasma level is decreased to below nanomolar concentrations.…”

Sildenafil citrate on experimental periodontitis in rats: Microtomographic and histological analyses

“…In addition, larger doses may increase the risk of side effects, which are almost always linked to the vasodilatory effect of the drug, such as headache, nasal congestion, abnormal vision, bradycardia, flushing and dyspnoea. In general, the reported side effects are transient, and severity may vary from mild to moderate (Lim et al., ; Padma‐Nathan, ).…”

Gender Specific Issues in Hereditary Ocular Disorders

“…Nearly 27 million men worldwide use sildenafil. 82 Although there are very well known side effects to using sildenafil such as headache, dyspepsia, flushing and cyanopsia, the majority of users are unaware of the potential risk of taking sildenafil if diagnosed with a hereditary retinal degeneration. 83 Behn et al studied the effect of sildenafil on retinal function in mice with autosomal recessive retinitis pigmentosa.…”