Economic Analysis of Sildenafil Citrate (Viagra??) Add-on to Treat Erectile Dysfunction Associated With Selective Serotonin Reuptake Inhibitor Use

A Review of Economic Evaluations of Erectile Dysfunction Therapies

INTRODUCTION

Erectile dysfunction (ED) is a common and costly urologic condition with increasing prevalence as men age. Cost-effectiveness of ED therapies and whether cost-effectiveness varies for different populations of men remains underexplored.

AIM

To review and summarize available published data on the economic evaluation of ED therapies and to identify gaps in the literature that still need to be addressed.

METHODS

All relevant peer-reviewed publications and conference abstracts were reviewed and incorporated.

RESULTS

There are a number of medical and surgical treatment options available for ED. The economic evaluation of phosphodiesterase-5 inhibitors, particularly sildenafil, has been well described. However, minimal research has been conducted to assess the cost-effectiveness of intracavernosal injections, intraurethral suppositories, penile prosthesis surgery, vacuum erection devices, and other emerging therapies in men with different causes of ED.

CONCLUSION

Available economic evaluations of ED therapies are dated, do not reflect present-day physician, pharmaceutical, and device costs, fail to account for patient comorbidities, and may not be generalizable to today's ED patients. Substantial research is needed to evaluate the cost-effectiveness of ED treatments across different patient populations, countries, and reimbursement systems. Rezaee ME, Ward CE, Brandes ER, et al. A Review of Economic Evaluations of Erectile Dysfunction Therapies. Sex Med Rev 2019;8:497-503.

Toward a new 'EPOCH': optimising treatment outcomes with phosphodiesterase type 5 inhibitors for erectile dysfunction

Despite the marked adverse impacts of erectile dysfunction (ED) on quality of life and well-being, many patients (and/or their partners) do not seek medical attention for this problem, do not receive treatment or discontinue such treatment even when it has effectively restored erectile responses to sexual stimulation. Phosphodiesterase type 5 (PDE5) inhibitors are considered first-line therapies for men with ED. To help physicians maximise the likelihood of treatment success with these agents, we conducted an English-language PubMed search of articles involving approved PDE5 inhibitors dating from 1 January 1998 (the year in which sildenafil citrate was introduced), through 31 August 2008. In addition to sildenafil, tadalafil and vardenafil, search terms included 'adhere*', 'couple*', 'effect*', 'effic*', 'partner*', 'satisf*', 'succe*' and 'treatment outcome.' Based on our analysis, physician activities to promote favourable treatment outcomes may be captured under the mnemonic 'EPOCH': (i) Evaluating and educating patients and partners to ensure realistic expectations of therapy; (ii) Prescribing a treatment individualised to the couple's lifestyle needs and other preferences; (iii) Optimising treatment outcomes by scheduling follow-up visits with the patient to 'fine-tune' dosages and revisit key educational messages; (iv) Controlling comorbidities via lifestyle counselling, medications and/or referrals and (v) Helping patients and their partners to meet their health and psychosocial needs, potentially referring them to a specialist for other forms of therapy if they are not satisfied with PDE5 inhibitors.

HIV-AIDS: urologic considerations

The prevalence of HIV continues to grow in the United States and worldwide. HIV-positive patients experience many genitourinary disease processes. With improvements in HIV therapy, patients have questions and concerns pertaining to their quality of life. This article reviews conditions such as HIV-related urinary tract infections, urolithiasis, voiding dysfunction, fertility, sexual dysfunction, HIV-related nephropathy, malignancies, and occupational exposure and prophylaxis. Knowledge of the various HIV manifestations of genitourinary conditions and their treatment options benefits clinicians and improves patient outcomes.

Principles of good practice for budget impact analysis: report of the ISPOR Task Force on good research practices--budget impact analysis

OBJECTIVES

There is growing recognition that a comprehensive economic assessment of a new health-care intervention at the time of launch requires both a cost-effectiveness analysis (CEA) and a budget impact analysis (BIA). National regulatory agencies such as the National Institute for Health and Clinical Excellence in England and Wales and the Pharmaceutical Benefits Advisory Committee in Australia, as well as managed care organizations in the United States, now require that companies submit estimates of both the cost-effectiveness and the likely impact of the new health-care interventions on national, regional, or local health plan budgets. Although standard methods for performing and presenting the results of CEAs are well accepted, the same progress has not been made for BIAs. The objective of this report is to present guidance on methodologies for those undertaking such analyses or for those reviewing the results of such analyses.

METHODS

The Task Force was appointed with the advice and consent of the Board of Directors of ISPOR. Members were experienced developers or users of budget impact models, worked in academia, industry, and as advisors to governments, and came from several countries in North America, Oceana, Asia, and Europe. The Task Force met to develop core assumptions and an outline before preparing a draft report. They solicited comments on the outline and two drafts from a core group of external reviewers and more broadly from the membership of ISPOR at two ISPOR meetings and via the ISPOR web site.

RESULTS

The Task Force recommends that the budget impact of a new health technology should consider the perspective of the specific health-care decision-maker. As such, the BIA should be performed using data that reflect, for a specific health condition, the size and characteristics of the population, the current and new treatment mix, the efficacy and safety of the new and current treatments, and the resource use and costs for the treatments and symptoms as would apply to the population of interest. The Task Force recommends that budget impact analyses be generated as a series of scenario analyses in the same manner that sensitivity analyses would be provided for CEAs. In particular, the input values for the calculation and the specific cost outcomes presented (a scenario) should be specific to a particular decision-maker's population and information needs. Sensitivity analysis should also be in the form of alternative scenarios chosen from the perspective of the decision-maker. The primary data sources for estimating the budget impact should be published clinical trial estimates and comparator studies for efficacy and safety of current and new technologies as well as, where possible, the decision-maker's own population for the other parameter estimates. Suggested default data sources also are recommended. These include the use of published data, well-recognized local or national statistical information and in special circumstances, expert opinion. Finally, the Task Force recommends that the analyst use the simplest design that will generate credible and transparent estimates. If a health condition model is needed for the BIA, it should reflect health outcomes and their related costs in the total affected population for each year after the new intervention is introduced into clinical practice. The model should be consistent with that used for the CEA with regard to clinical and economic assumptions.

CONCLUSIONS

The BIA is important, along with the CEA, as part of a comprehensive economic evaluation of a new health technology. We propose a framework for creating budget impact models, guidance about the acquisition and use of data to make budget projections and a common reporting format that will promote standardization and transparency. Adherence to these proposed good research practice principles would not necessarily supersede jurisdiction-specific budget impact guidelines, but may support and enhance local recommendations or serve as a starting point for payers wishing to promulgate methodology guidelines.

Factors that predict changing the type of phosphodiesterase type 5 inhibitor medication among men in the UK

OBJECTIVE

To evaluate predictors of changing the type of phosphodiesterase type 5 (PDE5) inhibitor (switching) among men with erectile dysfunction (ED) in the UK, the largest consumer of PDE5 inhibitors in Europe, as switching medication is often associated with higher resource use, and there are three oral PDE5 inhibitor medications currently available.

PATIENTS AND METHODS

Patients were identified from The Health Improvement Network database in the UK; men initiating therapy with sildenafil, tadalafil or vardenafil from May 2003 to August 2004 with >/= 6 months of prescription history before and after their initial PDE5 inhibitor prescription were included. Switching was evaluated as the proportion of second PDE5 inhibitor prescriptions that were for a drug differing from the first. Logistic regression was used to adjust for factors that might be associated with switching (dose, age and the presence of hypertension, dyslipidaemia, diabetes or depression).

RESULTS

Of the 2703 eligible men who initiated PDE5 inhibitor treatment during the study period, 91 (3.4%) switched to a different PDE5 inhibitor at their second prescription. The choice of initial PDE5 inhibitor therapy was a highly significant predictor of switching; men initiated on sildenafil were less likely to switch than those initiated on tadalafil (P < 0.001) or vardenafil (P < 0.003). Age and the presence of comorbidities were not significantly associated with switching (P > 0.05).

CONCLUSION

Initiating ED therapy with sildenafil was associated with the lowest rate of PDE5 inhibitor switching, which might reflect treatment satisfaction and patient preference.

Evaluation of erectile dysfunction therapy in patients previously nonadherent to long-term medications: a retrospective analysis of prescription claims

Erectile dysfunction (ED) can lead to treatment noncompliance in patients taking medications for chronic health conditions. Using the Intelligent Health Repository, NDCHealth's longitudinal, United States health care claims database, we examined the impact of treating ED on adherence to long-term therapies in previously nonadherent patients. Male patients >or=18 years of age were identified who received antidepressant (AD), antihypertensive (AH), oral hypoglycemic (OHG), or lipid-lowering (LL) agents and initiated therapy with sildenafil citrate (Viagra) between January and June 2003. Treatment adherence was determined using medication possession ratios (MPRs) for the 12 months before and after the first prescription of sildenafil. Prior to initiation of therapy for ED with sildenafil, 64% of patients with comorbid medications were not adherent (MPR <0.8). Among these patients, 728 (27%) received AD, 2112 (78%) received AH, 984 (18%) received OHG, and 1078 (40%) received LL agents, with 66% of patients receiving multiple therapeutic classes. During the 12-month period after the first sildenafil prescription, patients had a significant increase in medication adherence compared with the 12 months before the first prescription of sildenafil (P < 0.0001). The percentage of patients who became adherent (MPR >or=0.8) with medications after sildenafil treatment was from 22% to 36%. With the exception of the LL group, there was a significant relationship between >or=3 sildenafil prescriptions and change in MPR (P < 0.05). Patients aged >or=65 years had similar improvement in MPR as patients <or=65 years. Treatment of ED with sildenafil improved adherence in patients taking common long-term medications who were previously nonadherent.

Fluvoxamine affects sildenafil kinetics and dynamics

Sildenafil used as oral drug treatment for erectile dysfunction is predominantly metabolized by the cytochrome P450 isozyme 3A4. The antidepressant fluvoxamine is an inhibitor of cytochrome P450 3A4. In a randomized, double-blind, placebo-controlled, crossover study, we evaluated the effects of fluvoxamine dosed to steady state on the pharmacokinetics and pharmacodynamics of sildenafil. Twelve healthy men received oral fluvoxamine or placebo for 10 days (50 mg every day on days 1-3; 100 mg every day on days 4-10). On day 11, all participants received a single, oral, open-label dose of 50 mg sildenafil, and blood samples were collected for analysis of sildenafil plasma concentrations by liquid chromatography/mass spectrometry. Concurrently, the effect of sildenafil on venodilation induced by a constant dose of sodium nitroprusside was assessed using the dorsal hand vein compliance technique. Sildenafil was well tolerated in the presence of fluvoxamine. During fluvoxamine, sildenafil exposure (area under the curve) significantly increased by 40% (P < 0.001), and its half-life increased by 19% (P = 0.034). Concurrently, sodium nitroprusside-induced venodilation was significantly augmented by 59% during fluvoxamine compared to placebo (P = 0.012). In conclusion, sildenafil kinetics are mildly affected by fluvoxamine which translates into an increase in vascular sildenafil effects. Whereas the pharmacokinetic changes do not suggest a large clinically relevant interaction, it may be prudent to consider a starting dose of 25 mg in patients concurrently treated with fluvoxamine.

THE COSTS OF CARING FOR ERECTILE DYSFUNCTION IN A MANAGED CARE SETTING: EVIDENCE FROM A LARGE NATIONAL CLAIMS DATABASE

PURPOSE

We examined the direct costs of erectile dysfunction (ED) empirically.

MATERIALS AND METHODS

A naturalistic cohort study was done in 285,436 patients with ED and 51 health plans that covered 28 million lives nationwide from 1999 through 2001. Based on claims that had an ED related diagnosis code, procedure code or medication code we categorized the cost structure of ED care and calculated the annual costs of ED care per patient with ED, per user and per member monthly for individual and for all categories of ED care.

RESULTS

A patient with ED in a health plan spent about an average of 83.91 dollars in 1999, 95.41 dollars in 2000 and 119.26 dollars in 2001 for ED care. In 2001, 37.08% of ED care costs per patient with ED were spent on phosphodiesterase type 5 (PDE-5) inhibitor therapy, 14.36% were spent on physician office visits, 10.19% were spent on diagnosis procedures, 8.45% were spent on testosterone hormone therapy, 3.85% were spent on penile prosthesis implantation, 4.41% were spent on intracavernous injection, 2.68% were spent on alprostadil pellet insertion and 0.81% was spent on vacuum erection devices. Of the 7 commonly used ED treatments PDE-5 inhibitor therapy has the lowest annual cost per user.

CONCLUSIONS

In 2001 ED imposed a 122,669 dollars annual burden to a health plan with 100,000 members, that is or 0.108 dollars per member monthly. Each patient with ED spent 119.26 dollars annually for all ED related services or treatments. Of the 7 commonly used treatments PDE-5 inhibitor therapy had the lowest annual cost per user.

Female sexual dysfunction: the important points to remember

Media exposure regarding male sexual dysfunction and the growing number of viable treatment alternatives for erectile dysfunction has resulted in increasing numbers of men seeking clinical appointments and treatment for the condition, which has previously been considered taboo. Because these problems usually arise within the context of relationships, some investigators have alluded to increased rates of sexual dysfunction among the partners of these men. Also, since general practitioners, gynaecologists, geriatrists, and urologists are also seeing female patients for evaluation of various types of dysfunction, certain groups of these women with underlying chronic conditions have been noted to have high rates of concomitant sexual dysfunction. Physicians who have good rapport with these patients are in a privileged position to help with these intimate problems, which are often difficult for patients to discuss. Therefore, it is of extreme importance that these professionals become knowledgeable about and comfortable with the initial evaluation and possible treatment of female sexual dysfunction.

Health Care Cost Implications of Sildenafil Citrate

INTRODUCTION

As prescription drug expenditures increase, third-party payors are increasingly scrutinizing costs and reimbursement guidelines, such as for medications that treat chronic conditions that are not necessarily directly life threatening (i.e., obesity, nicotine addiction, and erectile dysfunction).

AIM

To review the costs and consequences of pharmacy benefit reimbursement policies related to erectile dysfunction therapies, using sildenafil citrate as the case study.

METHODS

Data and references were found through searches of PubMed and Google.

RESULTS AND CONCLUSIONS

To meet the varied health needs of a defined population under reasonable resource constraints requires analysis of cost and of the economic and non-economic consequences of a treatment. Based on analysis of sildenafil data, oral therapy of erectile dysfunction provides substantial cost savings when compared with other treatment options and contributes insignificant overall costs to health plans. Regardless, health plans impose controls to limit reimbursement. Because erectile dysfunction is often a precursor to other conditions, such limitations could compromise detection and management of underlying disease (e.g., depressive, cardiovascular, and urogenital). Reimbursement restrictions may also decrease membership satisfaction and re-enrollment rates.