Policy analysis of the conversion of histamine2 antagonists to over-the-counter use

Application of an economic evaluation approach to making regulatory decisions regarding access to medicines: advantages, challenges and recommendations

Initially patients require a prescription to access most new medicines. Some medicines may later be reclassified, allowing patients to access them without a prescription. Currently, Australian Therapeutic Goods Administration guidelines regarding reclassification decisions focus on patient risk rather than on potential benefits to patient health and the healthcare system. We conducted two extensive case studies demonstrating an economic evaluation approach to medicine reclassification in Australia, which were presented at various conferences and to key stakeholders. This article discusses the advantages and challenges of using an economic evaluation approach to inform medicine reclassification decisions. Advantages identified include systematically and transparently synthesising evidence from multiple sources; predicting the overall expected impact of reclassification on health outcomes and costs before it occurs; considering a broader range of risks and benefits; aggregation of health impacts into a single measure (quality-adjusted life years); identification of drivers of uncertainty; insight into the effects of different regulatory decisions; and improved consistency of evidence. Challenges include data availability and quality, estimating behavioural changes, model complexity, the lack of an incremental cost-effectiveness ratio threshold, and funding of economic analyses. We recommend that regulatory decision makers use an economic evaluation approach to help inform reclassification decisions, although economic evaluation results should be considered as part of the broader body of evidence. Ultimately, the use of an economic evaluation approach will contribute to helping decision makers maximise population health outcomes in an efficient way.What is known about the topic?In the past, decisions regarding medicine reclassification have generally been made using a deliberative approach focusing on patient risk. However, there are also potential benefits to patient health and effects on the healthcare system. Increasing awareness of these benefits have led to the development of alternative approaches to decision making, including an economic evaluation approach.What does this paper add?This article discusses the advantages and challenges of using an economic evaluation approach to inform medicine reclassification decisions compared with alternative approaches.What are the implications for practitioners?Economic evaluation results should be considered as part of the broader body of evidence regarding the types of health impacts, the extent of the available evidence, who will be affected, and the role of medical practitioners and pharmacists in mitigating any risks. However, awareness of the advantages and challenges of this approach in advance will help mitigate some of the challenges and increase acceptance of the economic evaluation results by decision makers and stakeholders.

Assessing the economic impact of Rx-to-OTC switches: systematic review and guidelines for future development

INTRODUCTION

Switching drugs from prescription to non-prescription status (Rx-to-OTC) presents a unique set of challenges and opportunities to policy-makers and the industry in terms of managing health outcomes, pharmaceutical spending, and steering of consumer choices of therapy. Decision-analytic models are used to address uncertainty and produce reasonable estimates of the economic impact of switches for payers. This article presents a critical literature review of existing models which assess the economic impact of Rx-to-OTC switches, and provides guidelines in which future economic evaluations of Rx-to-OTC switches could be improved.

METHODS

A comprehensive search strategy was implemented in Medline and Embase, to retrieve published economic evaluations on Rx-to-OTC switches from 1995-2010. The research digest of the International Society of Pharmacoeconomics and Outcomes Research (ISPOR) was reviewed for potentially relevant abstracts for the past 3 years. Each model used was critically evaluated in terms of structure, relevance of inputs, methodology used, and robustness of results.

RESULTS

Worldwide, the economic impact of Rx-to-OTC switches has only been evaluated in a total of 12 peer-reviewed publications. Ten out of 12 studies were US-based, and two European-based. The models covered various disease categories, including allergy, hypercholesterolemia, gastroenterology, contraception, pulmonology, and virology. Seventy-five per cent of the models predicted cost savings for payers and patients. Limitations of the models mainly included use of strong assumptions and non-inclusion of specific populations due to lack of data. Guidelines were developed to help future model development. They cover structural issues on decision context, health states, and clinical outcomes, and other considerations for model specifications.

CONCLUSIONS

Although reviewed studies lacked quality, this review of economic evidence of Rx-to-OTC switches suggests that switches may produce cost savings to public and private payers. This is especially important in light of the trend towards more switches.

Consumer usage patterns of nonprescription histamine2-receptor antagonists

OBJECTIVE

Prescription to over-the-counter (OTC) drug switches are increasingly common. Yet little is known about how the public uses these reclassified products. Histamine2-receptor antagonists (H2RAs) are popular examples, although they may be supplanted by OTC proton pump inhibitors (PPIs). We examined the extent to which consumers substitute OTC H2RAs for physician care and/or engage in off-label use of these medications.

METHODS

Self-administered anonymous survey of 1,116 adult OTC H2RA consumers in a random sample of 20 Los Angeles pharmacies from a major retail chain. Off-label use was defined by FDA warning label (e.g., bloody stools, dysphagia). Substitution was defined by intent to use H2RA instead of going to a physician.

RESULTS

Forty-six percent engaged in off-label use of OTC H2RAs. Off-label use was independently associated with lower income, substitution for physician care, prior gastrointestinal disease, and past prescription H2RA use. Thirty-four percent substituted OTC H2RA use for physician care, and 54% of these met the criteria for off-label use. Substitution was associated with lack of health insurance, lack of time to see a physician, the belief that OTC H2RA was cheaper than clinic visits, and nonwhite race.

CONCLUSION

Almost one-half of adult consumers reported using OTC H2RAs in a manner inconsistent with FDA labeling, and this off-label use was associated with substitution for physician care. Traditionally vulnerable populations were more prone to off-label use and to substituting H2RAs for physician care. Further studies are needed to assess patient outcomes, identify remedies, and explore implications for the reclassification of PPIs.

Usage patterns of over-the-counter phenazopyridine (pyridium)

OBJECTIVES

Little is known about how the public uses formerly prescription medications that are available over-the-counter (OTC). This study examines whether consumers inappropriately use and substitute a recently widely distributed OTC urinary analgesic, phenazopyridine, for provider care.

DESIGN/SETTING

We conducted a cross-sectional survey of a stratified cluster random sample of OTC phenazopyridine purchasers (N = 434) in 31 Los Angeles retail pharmacies over 5 months. Recruited by shelf advertisements, participants were 18 years or older who purchased a phenazopyridine product. Each completed a 25-item self-administered anonymous questionnaire. Inappropriate use was defined as 1) having medical contraindications to phenazopyridine, or 2) not having concurrent antibiotic and/or provider evaluation for the urinary symptoms.

RESULTS

The survey response rate was 58%. Fifty-one percent of the respondents used OTC phenazopyridine inappropriately, and 38% substituted it for medical care. Multiple logistic regression analyses revealed that inappropriate use was correlated with having little time to see a provider (odds ratio [OR], 1.57; 95% confidence interval [95% CI], 1.26 to 1.96), receiving friend's or family's advice (OR, 1.25; 95% CI, 1.05 to 1.47), having prior urinary tract infections (OR, 0.49; 95% CI, 0.30 to 0.80), having used prescription phenazopyridine, (OR, 0.40; 95% CI, 0.25 to 0.63), and having back pain (OR, 0.34; 95% CI, 0.16 to 0.74). Similar correlates were found in those who substituted OTC phenazopyridine for provider care. Respondents with incorrect knowledge about phenazopyridine's mode of action had 1.9 times greater odds of inappropriate use and 2.2 times greater odds of substitution than those who had correct knowledge about this drug.

CONCLUSION

Inappropriate use of OTC phenazopyridine appears common. Increasing the public's knowledge about reclassified drugs may help to mitigate this problem.

Cost impact of switching histamine(2)-receptor antagonists to nonprescription status

BACKGROUND

There is a recent trend to switching medications from prescription to nonprescription status. Often, such switches are accompanied by dramatic changes in utilization due to increased availability or decreased insurance coverage. The histamine(2)-receptor antagonists (H(2)RAs) underwent such status change in the UK in 1994, the US in 1995, and Canada in 1996.

OBJECTIVE

To examine the impact of the status change for H(2)RAs on the market for gastrointestinal (GI) agents in the US, UK, and Canada.

METHODS

IMS market sales data from 1992 to 1997 were procured. All costs were converted to 1997 US dollars using the consumer price index. Per capita sales figures were determined using population data from the US Census Bureau's International Database.

RESULTS

Overall spending on GI remedies increased in all 3 markets between 1992 and 1997; however, the contribution of prescription sales and number of prescriptions varied across the 3 countries. An increased market share for nonprescription H(2)RAs occurred in the US, correlating with a decline in prescription numbers for GI remedies. The opposing trend occurred in the UK, where market share of nonprescription H(2)RAs was minimal and use of prescription H(2)RAs increased. Prescription and nonprescription H(2)RA sales could not be differentiated for Canada.

CONCLUSIONS

The impact of the H(2)RA status change varied across countries. Differences in utilization may be attributed to many factors such as differing healthcare systems, patient convenience, and physician prescribing practices. Further research is required to identify the reasons for differences in utilization and to quantify the potential clinical impact.

The effect on social welfare of a switch of second-generation antihistamines from prescription to over-the-counter status: a microeconomic analysis

BACKGROUND

The US Food and Drug Administration (FDA) recently held a meeting to determine whether the status of second-generation antihistamines (SGAs) should be switched from prescription (Rx) to over-the-counter (OTC) status.

OBJECTIVE

This article provides a conceptual microeconomic framework for addressing issues regarding the impact of such a switch on social welfare.

METHODS

A review of the economic literature on Rx-to-OTC switches was conducted. Relevant articles published in English between 1990 and 2001 were identified through searches of ABI Info, EconLit, PsychInfo, MEDLINE, CANCERLIT, AIDSLINE, and HealthStar, as well as a general Internet search for statements in the press or on the FDA Web site. The search terms used were Rx, prescription, OTC, over-the-counter, second-generation antihistamines, nonsedating antihistamines, first-generation antihistamines, and sedating antihistamines. Microeconomic models focusing on consumer surplus were employed to determine the potential price response and social-welfare implications of a switch of SGAs to OTC status.

RESULTS

Unlike the agents involved in previous Rx-to-OTC switches, SGAs are still under patent protection. Economic theory suggests that a firm that is protected by a patent will price aggressively. The market for OTC SGAs is likely to be more elastic due to a lack of insurance coverage for OTC products; hence, drug manufacturers would be likely to charge a lower price if SGAs were sold OTC. However, a lower price does not necessarily guarantee an improvement in social welfare; the net impact is determined by whether the increase in consumer surplus outweighs the deadweight loss (losses of consumer and producer surplus not transferred to other parties). Additionally, the assumption of a price reduction would be called into question if there were inequalities in marginal costs between the Rx and OTC markets. In this situation, the postswitch price might increase or not be reduced significantly.

CONCLUSIONS

It is uncertain whether granting OTC status to SGAs would be cost saving to society, particularly as these drugs are patent protected. The social-welfare implications of such a switch would depend heavily on pricing strategies and consumer behavior. Further analyses are needed to determine how both factors influence social welfare; only then can the costs and benefits of a switch be understood completely.

Self-reported effectiveness and physician consultation rate in users of over-the-counter histamine-2 receptor antagonists

OBJECTIVE

Decreased physician visits for dyspepsia were predicted with the histamine-2 receptor antagonists (H2RA) release to over-the-counter (OTC) status. The aim of this study was to examine the presentation frequency for dyspeptic complaints before and after the OTC release of the H2RA and the self-reported effectiveness of OTC H2RA.

METHODS

Two cross-sectional surveys were used in a community sample. The patients comprised a random age- and sex-stratified sample of 1600 ambulatory adults in 1993 and 1800 in 1997. Self-report, valid mail surveys gathered information on healthcare seeking and gastrointestinal symptoms in 1993 and 1997 and antisecretory use in 1997.

RESULTS

Presentation frequency for dyspepsia was 22% in 1993 versus 23.5% in 1997. Only 16% of chronic users of the OTC H2RA obtained complete relief of symptomatic episodes. Use of an OTC H2RA was highly associated with presentation to a physician in the past year.

CONCLUSIONS

OTC H2RA infrequently provided the complete relief desired by patients. Presentation frequency to physicians for dyspeptic complaints did not change with availability of H2RA OTC.

The effect of an Rx-to-OTC switch on medication prescribing patterns and utilization of physician services: the case of H2-receptor antagonists

BACKGROUND

Prescription medications are being switched to over-the-counter (OTC) status with increasing frequency. Information is limited regarding the impact of OTC availability on the use of prescription forms of those products and on the utilization of health care services.

OBJECTIVES

To determine the impact of OTC availability of H2-receptor antagonists on medication prescribing patterns and utilization of physician services among a population of chronic users of those agents.

DESIGN

A retrospective study was conducted to evaluate changes in the number of prescriptions filled for H2-receptor antagonists and other gastrointestinal agents (proton pump inhibitors, gastric motility agents, and sucralfate), and ambulatory medical encounters with physicians during a one-year period before (July 1, 1994-June 30, 1995) and after OTC availability of H2-receptor antagonists (July 1, 1995-June 30, 1996). Changes in the prescription drug costs for gastrointestinal agents were also estimated.

SUBJECTS

Members of the Fallon Community Health Plan, a mixed-model HMO located in Central and Eastern Massachusetts (July 1, 1994-June 30, 1996) who were dispensed at least one H2-receptor antagonist during each quarter for the period between July 1, 1994 through June 30, 1995.

MEASURES

Mean absolute differences in the frequencies of drug dispensings and ambulatory encounters and prescription drug costs during the pre-OTC (July 1, 1994-June 30, 1995) and post-OTC switch (July 1, 1995-June 30, 1996) periods were calculated.

RESULTS

For the one-year period after OTC availability H2-receptor antagonists, we estimated that the mean absolute number of prescriptions dispensed for H2-receptor antagonists was reduced by 1.5 prescriptions (P < 0.001) and the mean number of prescriptions dispensed for all gastrointestinal agents was reduced by 1.3 prescriptions (P < 0.001) among chronic users of these agents. The number of dispensings of gastrointestinal agents was similarly reduced in the population of chronic users with a diagnosis of gastroesophageal reflux disease (GERD). OTC availability was not associated with an increase in physician visits, overall or for GERD-related conditions.

CONCLUSIONS

The findings of this study suggest that the prescription-to-OTC switch of H2-receptor antagonists reduced the number of prescriptions for those agents dispensed among a population of chronic users of those drugs in a managed care setting without increasing physician visits.

Low-cost therapeutic agents. Uses and abuses

The past quarter century has seen a transformation of the pharmaceutical industry from blind empiricism to the design of drugs to act as agonists or antagonists at specific receptor sites. As truly effective technology, many have led to marked savings in cost. Savings have been achieved when therapeutic drugs, often highly specific, can be substituted for surgery and other invasive procedures and when therapeutic drugs can be used to prevent illness and the need for treatment. Further savings are achieved with the reduced prescription of ineffective drugs. It is estimated that therapeutic drugs and vaccines contribute about half of medicine's contribution to increased life expectancy and improved quality of life in this century at about 7% of national expenditures for medical care in the United States.