Original Research-Ed Pharmacotherapy
A Systematic Review Assessing the Economic Impact of Sildenafil Citrate (Viagra®) in the Treatment of Erectile Dysfunction

https://doi.org/10.1111/jsm.12068Get rights and content

Abstract

Introduction

Sildenafil was the first oral phosphodiesterase type 5 (PDE5) inhibitor introduced as primary therapy for erectile dysfunction (ED). In the 7 years following its market launch, sildenafil was prescribed by more than 750,000 physicians to more than 23 million men worldwide. To date, few studies have evaluated the economic impact of sildenafil in treating ED.

Aim

To evaluate the cost‐effectiveness and impact of sildenafil on health care costs for patients with ED in multiple countries.

Main Outcomes Measures.

Economic outcomes including cost, cost‐effectiveness, cost of illness, cost consequence, resource use, productivity, work loss, and willingness to pay (WTP) were investigated.

Methods

Using keywords related to economic outcomes and sildenafil, we systematically searched literature published between July 2001 and July 2011 using MEDLINE and EMBASE. Included articles pertained to costs, WTP, and economic evaluations.

Results

In the last 10 years, 12 studies assessed economic outcomes associated with sildenafil for ED. Most studies were conducted in the United States and the United Kingdom, with one study identified in Canada and one from Mexico. Six studies evaluated cost of illness, cost consequence, or cost of care, and four studies evaluated WTP or drug pricing by country in the United States and the United Kingdom. In the United States and the United Kingdom, costs to health care systems have increased with demand for treatment. Cost analyses suggested that sildenafil would lower direct costs compared with other PDE5 inhibitors. US and UK studies found that patients exhibited WTP for sildenafil. The two cost‐effectiveness models we identified examined ED sub‐groups, those with spinal cord injury and those with diabetes or hypertension. These models indicated favorable cost‐effectiveness profiles for sildenafil compared with other active‐treatment options in both Mexico and Canada.

Conclusions

The relative value of sildenafil vs. surgically implanted prosthetic devices and other PDE5 inhibitors, is underscored by patients' WTP, and cost‐effectiveness in ED patients with comorbidities.

Introduction

Erectile dysfunction (ED) is the consistent inability of a man to achieve or maintain penile erection sufficient for sexual activity [1]. Common causes of ED include aging and endothelial dysfunction associated with behaviors such as smoking or conditions including type 2 diabetes mellitus (T2DM), hypertension (HTN), and other cardiovascular diseases. Psychological issues, including performance anxiety, stress, and depression can also cause ED. Additionally, selective serotonin reuptake inhibitors (SSRIs) have been found to cause sexual dysfunction in 40% to 70% of men seeking treatment for depression, amounting to 10 to 15 million patients worldwide [2]. According to the 2005 Global Better Sex Survey (GBSS), ED affects 13% to 28% of men aged 40 to 80 [3]. A 1999 study projected that the worldwide prevalence of ED would reach 322 million by 2025 [4]. In the United States, ED currently affects 18 million men and is expected to increase as the male population ages. US treatment costs are projected to approach $15 billion if all affected men sought treatment 5, 6.

Phosphodiesterase type‐5 (PDE5) inhibitors are accepted by many physicians as the standard‐of‐care in first‐line treatment of ED, with established efficacy and a favorable safety profile. PDE5 inhibitors work by preventing the degradation of cyclic guanosine monophosphate (cGMP), which relaxes smooth muscles, increasing blood flow to the penis. In 1998, sildenafil (Viagra®) was the first oral PDE5 inhibitor introduced as a primary therapy for ED. In the 7 years following its market launch, sildenafil had been prescribed by more than 750,000 physicians to more than 23 million men worldwide [7].

As a result of the wide uptake of sildenafil and other PDE5 inhibitors, recent worldwide trends suggest that the greatest increases in expenditures for ED will be for outpatient evaluation and treatment. The objective of this systematic literature review was to determine the economic impact of sildenafil on the direct costs of treatment for ED.

Section snippets

Aims

To evaluate the cost‐effectiveness and impact of sildenafil on health care costs for patients with ED in multiple countries.

Methods

A systematic literature review was conducted in MEDLINE and EMBASE using search algorithms to identify relevant economic publications in English on sildenafil in ED. The search identified publications with sildenafil and keywords to identify economic outcomes specifically: cost, budget, expenditure, resource use, economic, pharmacoeconomic, productivity, work loss, or willingness to pay (WTP). Using this broad set of terms allowed the search to identify the largest number of publications

Results

In the last 10 years (July 2001–July 2011), 12 publications 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 were identified that assessed economic outcomes associated with sildenafil as treatment for ED. Most studies were conducted in the United States and the United Kingdom, with one study identified in Canada [11] and one literature source from Mexico [19], which was the only study from a developing country. Only two models (Mexico [19] and Canada [11]) in ED populations with comorbid conditions

Discussion

This systematic review assessed the current literature and evidence on the economic impact for patients with ED treated with sildenafil. To our knowledge, this is the first literature review evaluating the body of evidence. We identified 12 economic studies published in the past 10 years, one of which focused on a developing country, Mexico. The remaining 11 studies evaluated economic outcomes in North America and the UK. In the past 10 years, no cost‐effectiveness models have been published on

Source of Funding

Amber Martin, Rachel Huelin, David Wilson, and Talia Foster are employees of UBC who were paid consultants to Pfizer in connection with the development of this manuscript. This study was funded by Pfizer Inc.

Category 1

  • (a) 

    Conception and Design

    Amber L. Martin; Rachel Huelin; Talia S. Foster; Joaquin F. Mould

  • (b) 

    Acquisition of Data

    Amber L. Martin; Rachel Huelin

  • (c) 

    Analysis and Interpretation of Data

    Amber L. Martin; Rachel Huelin; David Wilson; Talia S. Foster; Joaquin F. Mould

Category 2

  • (a) 

    Drafting the Article

    Amber L. Martin; Rachel Huelin; David Wilson; Talia S. Foster

  • (b) 

    Revising It for Intellectual Content

    Amber L. Martin; Rachel Huelin; David Wilson; Talia S. Foster; Joaquin F. Mould

Category 3

  • (a) 

    Final Approval of the Completed Article

    Amber L.

References (24)

  • E. Selvin et al.

    Prevalence and risk factors for erectile dysfunction in the US

    Am J Med

    (2007)
  • H. Wessells et al.

    Erectile dysfunction

    J Urol

    (2007)
  • N. Campbell et al.

    Internet‐ordered viagra (sildenafil citrate) is rarely genuine

    J Sex Med

    (2012)
  • A.M. Morales et al.

    Patients' preference in the treatment of erectile dysfunction: A critical review of the literature

    Int J Impot Res

    (2011)
  • H.G. Nurnberg

    Managing treatment‐emergent sexual dysfunction associated with serotonergic antidepressants: Before and after sildenafil

    J Psychiatr Pract

    (2001)
  • E.O. Laumann et al.

    Sexual problems among women and men aged 40–80 y: Prevalence and correlates identified in the Global Study of Sexual Attitudes and Behaviors

    Int J Impot Res

    (2005)
  • I.A. Ayta et al.

    The likely worldwide increase in erectile dysfunction between 1995 and 2025 and some possible policy consequences

    BJU Int

    (1999)
  • G. Jackson et al.

    Past, present, and future: A 7‐year update of Viagra (sildenafil citrate)

    Int J Clin Pract

    (2005)
  • M. Ashton‐Key et al.

    UK department of health guidance on prescribing for impotence following the introduction of sildenafil: Potential to contain costs in the average health authority district

    PharmacoEconomics

    (2002)
  • C.E. Cooke et al.

    Utilization and cost of sildenafil in a large managed care organization with a quantity limit on sildenafil

    J Manag Care Pharm

    (2005)
  • J.P. Harnett et al.

    The economic effect of switching from sildenafil to another phosphodiesterase type 5 inhibitor

    Manag Care Interface

    (2006)
  • N. Mittmann et al.

    Erectile dysfunction in spinal cord injury: A cost‐utility analysis

    J Rehabil Med

    (2005)
  • Cited by (20)

    • A Review of Economic Evaluations of Erectile Dysfunction Therapies

      2020, Sexual Medicine Reviews
      Citation Excerpt :

      Furthermore, Plumb and Guest25 examined the cost burden of ED in the United Kingdom and found it to be relatively small at £53,000,000, with pharmaceutical drugs accounting for only 21.7% of total costs. In a 2013 systematic review sponsored by Pfizer, Martin et al26 identified 12 studies that assessed economic outcomes associated with sildenafil relative to other ED therapies. They concluded that sildenafil was economically superior to other PDE5 inhibitors and surgically implanted prostheses, based on a myriad of studies using different types of economic evaluation techniques.26

    • Social and Economic Impacts of Managing Sleep Hypoventilation Syndromes

      2017, Sleep Medicine Clinics
      Citation Excerpt :

      Note that ASV is not indicated in patients with hypoventilation because of its inability to enhance ventilatory support. Using quality-adjusted life years (QALY) as a marker, PAP therapy has a cost of US$2100/QALY compared with US$81,000/QALY for generic statins and US$11,000/QALY for ED.109–111 The cost, including attended PSG testing, is small given the significant health benefits and long-term economic savings.

    • Implanted Muscle-Derived Stem Cells Ameliorate Erectile Dysfunction in a Rat Model of Type 2 Diabetes, but Their Repair Capacity Is Impaired by Their Prior Exposure to the Diabetic Milieu

      2016, Journal of Sexual Medicine
      Citation Excerpt :

      Erectile dysfunction (ED) is a major complication of type 2 diabetes (T2D) affecting more than 60% to 75% of men with diabetes.1,2 It impairs the quality of life of patients and their partners and leads to considerable health costs.3,4 Erectile dysfunction also is prevalent in obese patients and those with metabolic syndrome.5–7

    • Management of ED under the "severe distress" criteria in the NHS: A real-life study

      2014, Journal of Sexual Medicine
      Citation Excerpt :

      Tadalafil was the preferred PDE5‐I in our series in line with the published literature [15–17]. This may be explained in part by the fact that tadalafil was the preferred choice of prescription from the andrology clinic, in spite of cost implications [18]. Another reason for the high use of tadalafil can be attributed to the clinical effects of tadalafil, which have been shown to be effective for up to 36 hours after administration, longer than the other PDE5‐Is, which are effective for only 4–5 hours after dosing [19].

    View all citing articles on Scopus

    Conflict of Interest: The authors have no conflicts to report.

    View full text