Economic Evaluations of Establishing Opioid Overdose Prevention Centers in 12 North American Cities: A Systematic Review

OBJECTIVES

Overdose prevention centers (OPCs) provide a safe place where people can consume preobtained drugs under supervision so that a life-saving medical response can be provided quickly in the event of an overdose. OPCs are programs that are established in Canada and have recently become legally sanctioned in only a few United States jurisdictions.

METHODS

We conducted a systematic review that summarizes and identifies gaps of economic evidence on establishing OPCs in North America to guide future expansion of OPCs.

RESULTS

We included 16 final studies that were evaluated with the Consolidated Health Economic Evaluation Reporting Standards and Drummond checklists. Eight studies reported cost-effectiveness results (eg, cost per overdose avoided or cost per quality-adjusted life-year), with 6 also including cost-benefit; 5 reported only cost-benefit results, and 3 cost offsets. Health outcomes primarily included overdose mortality outcomes or HIV/hepatitis C virus infections averted. Most studies used mathematical modeling and projected OPC outcomes using the experience of a single facility in Vancouver, BC.

CONCLUSIONS

OPCs were found to be cost-saving or to have favorable cost-effectiveness or cost-benefit ratios across all studies. Future studies should incorporate the experience of OPCs established in various settings and use a greater diversity of modeling designs.

Cost of providing co-located hepatitis C treatment at a syringe service program exceeds potential reimbursement: Results from a clinical trial

Background

Co-located hepatitis C treatment at syringe service programs (SSP) is an emerging model of care for people who inject drugs (PWID). Implementation of these models can be informed by understanding the program costs.

Methods

We conducted an economic evaluation of a hepatitis C treatment intervention at an SSP in New York City implemented as one arm of a randomized trial from 2017 to 2021. Start-up and operating costs were determined from the treatment program's perspective using micro-costing and were compared to potential Medicaid reimbursement. We applied nationally representative unit costs and wage rates. Results are reported in 2020 USD.

Results

The treatment program was staffed by one physician and one care coordinator. Participants were offered hepatitis C clinical evaluation and treatment, a 45-min reinfection prevention education session, and additional care coordination as needed. The trial enrolled 84 PWID with hepatitis C in the intervention arm; 64 initiated treatment and 55 achieved sustained virological response. Start-up costs including training and equipment totaled $4677. Overhead costs including rent, utilities and software totaled $2229 per month. Clinical and care coordination totaled $4867 per participant, of which $3722 was care coordination. The total cost excluding startup was $6035 per enrolled participant and $7921 per treated participant; estimated potential reimbursement was $628 per enrolled participant.

Conclusion

Our results provide insight to US-based SSPs seeking to provide co-located hepatitis C care and highlight the intensive care coordination services provided. Successful implementation likely requires funding sources beyond health insurers or substantial changes to insurance reimbursement for care coordination.

Cost-effectiveness implications of increasing the efficiency of the extended-release naltrexone induction process for the treatment of opioid use disorder: a secondary analysis

BACKGROUND AND AIMS

In a US randomized-effectiveness trial comparing extended-release naltrexone (XR-NTX) with buprenorphine-naloxone (BUP-NX) for the prevention of opioid relapse among participants recruited during inpatient detoxification (CTN-0051), the requirement to complete opioid detoxification prior to initiating XR-NTX resulted in lower rates of initiation of XR-NTX (72% XR-NTX versus 94% BUP-NX).

DESIGN

This was a retrospective secondary analysis of CTN-0051 trial data, including follow-up data over 24-36 weeks.

SETTING

Eight community-based, inpatient-detoxification and follow-up outpatient treatment facilities in the United States.

PARTICIPANTS

A total of 283 participants randomized to receive XR-NTX.

MEASUREMENTS

Efficiency was estimated using a multivariable generalized structural equation model to explore simultaneous determinants of XR-NTX induction and induction duration (detoxification + residential days). Cost-effectiveness was estimated from the health-care sector perspective and included expected costs and quality-adjusted life-years (QALYs).

FINDINGS

Treatment site was the only modifiable factor that simultaneously increased the likelihood of XR-NTX induction and decreased induction duration. Incorporating the higher predicted probability of XR-NTX induction, and fewer predicted days of detoxification and subsequent residential treatment into the cost-effectiveness framework, reduced the incremental average 24-week total cost of XR-NTX treatment from $5317 more than that of BUP-NX (P = 0.01) to a non-statistically-significant difference of $1016 (P = 0.63). QALYs gained remained similar across arms.

CONCLUSION

Adopting an efficient model of extended-release naltrexone initiation could result in extended-release naltrexone and buprenorphine-naloxone being of comparable economic value from the health-care sector perspective over 24-36 weeks for patients seeking treatment for opioid use disorder at an inpatient detoxification facility.

Economic Evaluations of Pharmacologic Treatment for Opioid Use Disorder: A Systematic Literature Review

OBJECTIVE

The crisis of opioid use puts a strain on resources in the United States and worldwide. There are 3 US Food and Drug Administration-approved medications for treatment of opioid use disorder: methadone, buprenorphine, and injectable extended-release naltrexone (XR-NTX). The comparative effectiveness and cost vary considerably among these 3 medications. Economic evaluations provide evidence that help stakeholders efficiently allocate scarce resources. Our objective was to summarize recent health economic evidence of pharmacologic treatment of opioid use disorder interventions.

METHODS

We searched PubMed for peer-reviewed studies in English from August 2015 through December 2019 as an update to a 2015 review. We used the Drummond checklist to evaluate and categorize economic evaluation study quality. We summarized results by economic evaluation methodology and pharmacologic treatment modality.

RESULTS

We identified 105 articles as potentially relevant and included 21 (4 cost-offset studies and 17 cost-effectiveness/cost-benefit studies). We found strengthened evidence on buprenorphine and methadone, indicating that these treatments are economically advantageous compared with no pharmacotherapy, but found limited evidence on XR-NTX. Only half of the cost-effectiveness studies used a generic preference-based measure of effectiveness, limiting broad comparison across diseases/disorders. The disease/disorder-specific cost-effectiveness measures vary widely, suggesting a lack of consensus on the value of substance use disorder treatment.

CONCLUSION

We found studies that provide new evidence supporting the cost-effectiveness of buprenorphine compared with no pharmacotherapy. We found a lack of evidence supporting superior economic value for buprenorphine versus methadone, suggesting that both are attractive alternatives. Further economic research is needed on XR-NTX, as well as other emerging pharmacotherapies, treatment modalities, and dosage forms.

Harmonizing healthcare and other resource measures for evaluating economic costs in substance use disorder research

BACKGROUND

Standardization and harmonization of healthcare resource utilization data can improve evaluations of the economic impact of treating people with substance use disorder (SUD), including reductions in use of expensive hospital and emergency department (ED) services, and can ensure consistency with current cost-effectiveness and cost-benefit analysis guidelines.

METHODS

We examined self-reported healthcare and other resource utilization data collected at baseline from three National Institute on Drug Abuse (NIDA)-funded Seek, Test, Treat, and Retain intervention studies of individuals living with/at risk for HIV with SUD. Costs were calculated by multiplying mean healthcare resource utilization measures by monetary conversion factors reflecting cost per unit of care. We normalized baseline recall timeframes to past 30 days and evaluated for missing data.

RESULTS

We identified measures that are feasible and appropriate for estimating healthcare sector costs including ED visits, inpatient hospital and residential facility stays, and outpatient encounters. We also identified two self-reported measures to inform societal costs (days experiencing SUD problems, participant spending on substances). Missingness was 8% or less for all study measures and was lower for single questions measuring utilization in a recall period.

CONCLUSIONS

We recommend including measures representing units of service with specific recall periods (e.g., 6 months vs. lifetime), and collecting healthcare resource utilization data using single-question measures to reduce missingness.

Cost-effectiveness of Hepatitis C Virus Treatment Models for People Who Inject Drugs in Opioid Agonist Treatment Programs

BACKGROUND

Many people who inject drugs in the United States have chronic hepatitis C virus (HCV). On-site treatment in opiate agonist treatment (OAT) programs addresses HCV treatment barriers, but few evidence-based models exist.

METHODS

We evaluated the cost-effectiveness of HCV treatment models for OAT patients using data from a randomized trial conducted in Bronx, New York. We used a decision analytic model to compare self-administered individual treatment (SIT), group treatment (GT), directly observed therapy (DOT), and no intervention for a simulated cohort with the same demographic characteristics of trial participants. We projected long-term outcomes using an established model of HCV disease progression and treatment (hepatitis C cost-effectiveness model: HEP-CE). Incremental cost-effectiveness ratios (ICERs) are reported in 2016 US$/quality-adjusted life years (QALY), discounted 3% annually, from the healthcare sector and societal perspectives.

RESULTS

For those assigned to SIT, we projected 89% would ever achieve a sustained viral response (SVR), with 7.21 QALYs and a $245 500 lifetime cost, compared to 22% achieving SVR, with 5.49 QALYs and a $161 300 lifetime cost, with no intervention. GT was more efficient than SIT, resulting in 0.33 additional QALYs and a $14 100 lower lifetime cost per person, with an ICER of $34 300/QALY, compared to no intervention. DOT was slightly more effective and costly than GT, with an ICER > $100 000/QALY, compared to GT. In probabilistic sensitivity analyses, GT and DOT were preferred in 91% of simulations at a threshold of <$100 000/QALY; conclusions were similar from the societal perspective.

CONCLUSIONS

All models were associated with high rates of achieving SVR, compared to standard care. GT and DOT treatment models should be considered as cost-effective alternatives to SIT.

Implementation of a nationwide health economic consultation service to assist substance use researchers: Lessons learned

BACKGROUND

Health economic evaluation findings assist stakeholders in improving the quality, availability, scalability, and sustainability of evidence-based services, and in maximizing the efficiency of service delivery. The Center for Health Economics of Treatment Interventions for Substance Use Disorders, HCV, and HIV (CHERISH) is a NIDA-funded multi-institutional center of excellence whose mission is to develop and disseminate health-economic research on healthcare utilization, health outcomes, and health-related behaviors that informs substance use disorder treatment policy, and HCV and HIV care of people who use substances.

METHODS

We designed a consultation service that is free to researchers whose work aligns with CHERISH's mission. The service includes up to six hours of consulting time. After prospective consultees submit their request online, they receive a screening call from the consultation service director, who connects them with a consultant with relevant expertise. Consultees and consultants complete web-based evaluations following the consultation; consultees also complete a six-month follow-up. We report on the status of the service from its inception in July 2015 through June 2017.

RESULTS

We have received 28 consultation requests (54% Early Stage Investigators, 57% MD or equivalent, 28% PhD, 61% women) on projects typically related to planning a study or grant application (93%); 71% were HIV/AIDS-related. Leading topics included cost-effectiveness (43%), statistical-analysis/econometrics (36%), cost (32%), cost-benefit (21%), and quality-of-life (18%). All consultees were satisfied with their overall experience, and felt that consultation expectations and objectives were clearly defined and the consultant's expertise was matched appropriately with their needs. Results were similar for consultants, who spent a median of 3 hours on consultations.

CONCLUSIONS

There is a need for health-economic methodological guidance among substance use, HCV, and HIV researchers. Lessons learned pertain to the feasibility of service provision, the need to implement systems to measure and improve service value, and strategies for service promotion.

Cost-Effectiveness of Buprenorphine-Naloxone Versus Extended-Release Naltrexone to Prevent Opioid Relapse

BACKGROUND

Not enough evidence exists to compare buprenorphine-naloxone with extended-release naltrexone for treating opioid use disorder.

OBJECTIVE

To evaluate the cost-effectiveness of buprenorphine-naloxone versus extended-release naltrexone.

DESIGN

Cost-effectiveness analysis alongside a previously reported randomized clinical trial of 570 adults in 8 U.S. inpatient or residential treatment programs.

DATA SOURCES

Study instruments.

TARGET POPULATION

Adults with opioid use disorder.

TIME HORIZON

24-week intervention with an additional 12 weeks of observation.

PERSPECTIVE

Health care sector and societal.

INTERVENTIONS

Buprenorphine-naloxone and extended-release naltrexone.

OUTCOME MEASURES

Incremental costs combined with incremental quality-adjusted life-years (QALYs) and incremental time abstinent from opioids.

RESULTS OF BASE-CASE ANALYSIS

Use of the health care sector perspective and a willingness-to-pay threshold of $100 000 per QALY showed buprenorphine-naloxone to be preferable to extended-release naltrexone in 97% of bootstrap replications at 24 weeks and in 85% at 36 weeks. Similar results were obtained with incremental time abstinent from opioids as an outcome and with use of the societal perspective.

RESULTS OF SENSITIVITY ANALYSIS

The base-case results were sensitive to the cost of the 2 treatments and the success of randomized treatment initiation.

LIMITATION

Relatively short follow-up for a chronic condition, substantial missing data, no information on patient out-of-pocket and social service costs.

CONCLUSION

Buprenorphine-naloxone is preferred to extended-release naltrexone as first-line treatment when both options are clinically appropriate and patients require detoxification before initiating extended-release naltrexone.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse, National Institutes of Health.

Closing the gaps in opioid use disorder research, policy and practice: conference proceedings

Drug overdose deaths involving opioids have surged in recent years and the economic cost of the opioid epidemic is estimated to be over $500 billion annually. In the midst of calls for declaring a national emergency, health policy decision makers are considering the best ways to allocate resources to curb the epidemic. On June 9, 2017, 116 invited health researchers, clinicians, policymakers, health system leaders, and other stakeholders met at the University of Pennsylvania to discuss approaches to address the gaps in evidence-based substance use disorder policy and practice, with an emphasis on the opioid epidemic. The conference was sponsored by the Center for Health Economics of Treatment Interventions for Substance Use Disorder, HCV, and HIV (CHERISH), a NIDA-funded National Center of Excellence, and hosted by the Leonard Davis Institute of Health Economics of the University of Pennsylvania. The conference aims were to: (1) foster new relationships between researchers and policymakers through a collaborative work process and (2) generate evidence-based policy recommendations to address the opioid epidemic. The conference concluded with an interactive work session during which attendees self-identified as researchers or policymakers and were divided equally among 13 tables. These groups met to develop and present policy recommendations based on an opioid use disorder case study. Thirteen policy recommendations emerged across four themes: (1) quality of treatment, (2) continuity of care, (3) opioid prescribing and pain management, and (4) consumer engagement. This conference serves as a proposed model to develop equitable, working relationships among researchers, clinicians, and policymakers.

Cost of pharmacotherapy for opioid use disorders following inpatient detoxification

OBJECTIVES

To estimate the costs of providing extended-release injectable naltrexone (XR-NTX) and buprenorphine-naloxone (BUP-NX) following inpatient detoxification using data derived from a multisite randomized controlled trial at 8 US community-based treatment programs.

STUDY DESIGN

Cost data were collected for 3 intervention phases: program start-up, inpatient detoxification, and up to 24 weeks of medication induction and management visits (post detoxification). Cost analyses were from the healthcare sector perspective (2015 US$); patient costs are also reported.

METHODS

We conducted site visits, administered a cost survey to treatment programs, and analyzed study data on medication and services utilization. Nationally representative sources were used to estimate unit costs. Uncertainty was evaluated in sensitivity analyses.

RESULTS

Mean start-up costs were $1071 per program for XR-NTX and $828 per program for BUP-NX. Mean costs per participant were $5416 for XR-NTX (57% detoxification, 37% medication, 3% provider, 3% patient) and $4148 for BUP-NX (64% detoxification, 12% medication, 10% provider, 14% patient). Total cost per participant ranged by site from $2979 to $8963 for XR-NTX and from $2521 to $6486 for BUP-NX.

CONCLUSIONS

For treatment providers, offering XR-NTX and/or BUP-NX as part of existing detoxification treatment modalities generates modest costs in addition to the costs of detoxification, which vary substantially among the 8 sites. From the patient's perspective, the costs associated with medication management visits may be a barrier for some individuals considering these treatments.

Criminal justice measures for economic data harmonization in substance use disorder research

BACKGROUND

The consequences of substance use disorders (SUDs) are varied and broad, affecting many sectors of society and the economy. Economic evaluation translates these consequences into dollars to examine the net economic impact of interventions for SUD, and associated conditions such as HCV and HIV. The nexus between substance use and crime makes criminal justice outcomes particularly significant for estimating the economic impact of SUD interventions, and important for data harmonization.

METHODS

We compared baseline data collected in six NIDA-funded Seek, Test, Treat and Retain (STTR) intervention studies that enrolled HIV-infected/at-risk individuals with SUDs (total n = 3415). Criminal justice measures included contacts with the criminal justice system (e.g., arrests) and criminal offenses. The objective was to develop a list of recommended measures and methods supporting economic data harmonization opportunities in HIV and SUD research, with an initial focus on crime-related outcomes.

RESULTS

Criminal justice contacts and criminal offenses were highly variable across studies. When measures grouped by offense classifications were compared, consistencies across studies emerged. Most individuals report being arrested for property or public order crimes (> 50%); the most commonly reported offenses were prostitution/pimping, larceny/shoplifting, robbery, and household burglary.

CONCLUSIONS

We identified four measures that are feasible and appropriate for estimating the economic consequences of SUDs/HIV/HCV: number of arrests, number of convictions, days of incarceration, and times committing criminal offenses, by type of offense. To account for extreme variation, grouping crimes by offense classification or calculating monthly averages per event allows for more meaningful comparisons across studies.

Cost-effectiveness of hepatitis C screening and treatment linkage intervention in US methadone maintenance treatment programs

BACKGROUND

We evaluated the cost-effectiveness of a hepatitis C (HCV) screening and active linkage to care intervention in US methadone maintenance treatment (MMT) patients using data from a randomized trial conducted in New York City and San Francisco.

METHODS

We used a decision analytic model to compare 1) no intervention; 2) HCV screening and education (control); and 3) HCV screening, education, and care coordination (active linkage intervention). We also explored an alternative strategy wherein HCV/HIV co-infected participants linked elsewhere. Trial data include population characteristics (67% male, mean age 48, 58% HCV infected) and linkage rates. Data from published sources include treatment efficacy and HCV re-infection risk. We projected quality-adjusted life years (QALYs) and lifetime medical costs using an established model of HCV (HEP-CE). Incremental cost-effectiveness ratios (ICERs) are in 2015 US$/QALY discounted 3% annually.

RESULTS

The control strategy resulted in a projected 35% linking to care within 6 months and 31% achieving sustained virologic response (SVR). The intervention resulted in 60% linking and 54% achieving SVR with an ICER of $24,600/QALY compared to no intervention from the healthcare sector perspective and was a more efficient use of resources than the control strategy. The intervention had an ICER of $76,500/QALY compared to the alternative strategy. From a societal perspective, the intervention had a net monetary benefit of $511,000-$975,600.

CONCLUSIONS

HCV care coordination interventions that include screening, education and active linkage to care in MMT settings are likely cost-effective at a conventional $100,000/QALY threshold for both HCV mono-infected and HIV co-infected patients.

Injectable naltrexone, oral naltrexone, and buprenorphine utilization and discontinuation among individuals treated for opioid use disorder in a United States commercially insured population

We investigated prescribing patterns for four opioid use disorder (OUD) medications: 1) injectable naltrexone, 2) oral naltrexone, 3) sublingual or oralmucosal buprenorphine/naloxone, and 4) sublingual buprenorphine as well as transdermal buprenorphine (which is approved for treating pain, but not OUD) in a nationally representative claims-based database (Truven Health MarketScan®) of commercially insured individuals in the United States. We calculated the prevalence of OUD in the database for each year from 2010 to 2014 and the proportion of diagnosed patient months on OUD medication. We compared characteristics of individuals diagnosed with OUD who did and did not receive these medications with bivariate descriptive statistics. Finally, we fit a Cox proportional hazards model of time to discontinuation of therapy as a function of therapy type, controlling for relevant confounders. From 2010 to 2014, the proportion of commercially insured individuals diagnosed with OUD grew by fourfold (0.12% to 0.48%), but the proportion of diagnosed patient-months on medication decreased from 25% in 2010 (0.05% injectable naltrexone, 0.4% oral naltrexone, 23.1% sublingual or oralmucosal buprenorphine/naloxone, 1.5% sublingual buprenorphine, and 0% transdermal buprenorphine) to 16% in 2014 (0.2% injectable naltrexone, 0.4% oral naltrexone, 13.8% sublingual or oralmucosal buprenorphine/naloxone, 1.4% sublingual buprenorphine, and 0.3% transdermal buprenorphine). Individuals who received medication therapy were more likely to be male, younger, and have an additional substance use disorder compared with those diagnosed with OUD who did not receive medication therapy. Those prescribed injectable naltrexone were more often male, younger, and diagnosed with additional substance use disorders compared with those prescribed other medications for opioid use disorder (MOUDs). At 30 days after initiation, 52% for individuals treated with injectable naltrexone, 70% for individuals treated with oral naltrexone, 31% for individuals treated with sublingual or oralmucosal buprenorphine/naloxone, 58% for individuals treated with sublingual buprenorphine, and 51% for individuals treated with transdermal buprenorphine discontinued treatment. In the Cox proportional hazard model, use of injectable naltrexone, oral naltrexone, sublingual buprenorphine, and transdermal buprenorphine were all associated with significantly greater hazard of discontinuing therapy beginning >30days after MOUD initiation (HR=2.17, 2.54, 1.15, and 2.21, respectively, 95% CIs 2.04-2.30, 2.45-2.64, 1.10-1.19, and 2.11-2.33), compared with the use of sublingual or oralmucosal buprenorphine/naloxone. This analysis demonstrates that the use of evidence-based medication therapies has not kept pace with increases in OUD diagnoses in commercially insured populations in the United States. Among those who have been treated, discontinuation rates >30days after initiation are high. The proportion treated with injectable naltrexone, oral naltrexone, and transdermal buprenorphine grew over time but remains small, and the discontinuation rates are higher among those treated with these medications compared with those treated with sublingual or oralmucosal buprenorphine/naloxone. In the face of the opioid overdose and addiction crisis, new efforts are needed at the provider, health system, and policy levels so that MOUD availability and uptake keep pace with new OUD diagnoses and OUD treatment discontinuation is minimized.

Cost-Effectiveness of One-Time Hepatitis C Screening Strategies Among Adolescents and Young Adults in Primary Care Settings

Background

High hepatitis C virus (HCV) rates have been reported in young people who inject drugs (PWID). We evaluated the clinical benefit and cost-effectiveness of testing among youth seen in communities with a high overall number of reported HCV cases.

Methods

We developed a decision analytic model to project quality-adjusted life years (QALYs), costs (2016 US$), and incremental cost-effectiveness ratios (ICERs) of 9 strategies for 1-time testing among 15- to 30-year-olds seen at urban community health centers. Strategies differed in 3 ways: targeted vs routine testing, rapid finger stick vs standard venipuncture, and ordered by physician vs by counselor/tester using standing orders. We performed deterministic and probabilistic sensitivity analyses (PSA) to evaluate uncertainty.

Results

Compared to targeted risk-based testing (current standard of care), routine testing increased the lifetime medical cost by $80 and discounted QALYs by 0.0013 per person. Across all strategies, rapid testing provided higher QALYs at a lower cost per QALY gained and was always preferred. Counselor-initiated routine rapid testing was associated with an ICER of $71000/QALY gained. Results were sensitive to offer and result receipt rates. Counselor-initiated routine rapid testing was cost-effective (ICER <$100000/QALY) unless the prevalence of PWID was <0.59%, HCV prevalence among PWID was <16%, reinfection rate was >26 cases per 100 person-years, or reflex confirmatory testing followed all reactive venipuncture diagnostics. In PSA, routine rapid testing was the optimal strategy in 90% of simulations.

Conclusions

Routine rapid HCV testing among 15- to 30-year-olds may be cost-effective when the prevalence of PWID is >0.59%.

Cost-Effectiveness Analysis of Probiotic Use to Prevent Clostridium difficile Infection in Hospitalized Adults Receiving Antibiotics

Background

Systematic reviews with meta-analyses and meta-regression suggest that timely probiotic use can prevent Clostridium difficile infection (CDI) in hospitalized adults receiving antibiotics, but the cost effectiveness is unknown. We sought to evaluate the cost effectiveness of probiotic use for prevention of CDI versus no probiotic use in the United States.

Methods

We programmed a decision analytic model using published literature and national databases with a 1-year time horizon. The base case was modeled as a hypothetical cohort of hospitalized adults (mean age 68) receiving antibiotics with and without concurrent probiotic administration. Projected outcomes included quality-adjusted life-years (QALYs), costs (2013 US dollars), incremental cost-effectiveness ratios (ICERs; $/QALY), and cost per infection avoided. One-way, two-way, and probabilistic sensitivity analyses were conducted, and scenarios of different age cohorts were considered. The ICERs less than $100000 per QALY were considered cost effective.

Results

Probiotic use dominated (more effective and less costly) no probiotic use. Results were sensitive to probiotic efficacy (relative risk <0.73), the baseline risk of CDI (>1.6%), the risk of probiotic-associated bactermia/fungemia (<0.26%), probiotic cost (<$130), and age (>65). In probabilistic sensitivity analysis, at a willingness-to-pay threshold of $100000/QALY, probiotics were the optimal strategy in 69.4% of simulations.

Conclusions

Our findings suggest that probiotic use may be a cost-effective strategy to prevent CDI in hospitalized adults receiving antibiotics age 65 or older or when the baseline risk of CDI exceeds 1.6%.

Monetary conversion factors for economic evaluations of substance use disorders

AIMS

Estimating the economic consequences of substance use disorders (SUDs) is important for evaluating existing programs and new interventions. Policy makers in particular must weigh program effectiveness with scalability and sustainability considerations in deciding which programs to fund with limited resources. This study provides a comprehensive list of monetary conversion factors for a broad range of consequences, services, and outcomes, which can be used in economic evaluations of SUD interventions (primarily in the United States), including common co-occurring conditions such as HCV and HIV.

METHODS

Economic measures were selected from standardized clinical assessment instruments that are used in randomized clinical trials and other research studies (e.g., quasi-experimental community-based projects) to evaluate the impact of SUD interventions. National datasets were also reviewed for additional SUD-related consequences, services, and outcomes. Monetary conversion factors were identified through a comprehensive literature review of published articles as well as targeted searches of other sources such as government reports.

RESULTS

Eight service/consequence/outcome domains were identified containing more than sixty monetizable measures of medical and behavioral health services, laboratory services, SUD treatment, social services, productivity outcomes, disability outcomes, criminal activity and criminal justice services, and infectious diseases consequences. Unit-specific monetary conversion factors are reported, along with upper and lower bound estimates, whenever possible.

CONCLUSIONS

Having an updated and standardized source of monetary conversion factors will facilitate and improve future economic evaluations of interventions targeting SUDs and other risky behaviors. This exercise should be repeated periodically as new sources of data become available to maintain the timeliness, comprehensiveness, and quality of these estimates.

The structural and health policy environment for delivering integrated HIV and substance use disorder treatments in Puerto Rico

Background

HIV prevalence in Puerto Rico is nearly twice that of the mainland United States, a level that was substantially fueled by injection drug use. Puerto Rico has a longstanding history of health provision by the public sector that directly affects how HIV and substance use disorder (SUD) treatment services are provided and funded. As part of pre-implementation research for a randomized trial of a community-level intervention to enhance HIV care access for substance users in San Juan, Puerto Rico, we sought to understand the structural and health policy environment for providing HIV and SUD treatments.

Methods

We conducted semi-structured qualitative interviews (n = 8) with government and program administrators in English and Spanish. Data were analyzed to identify dominant and recurrent themes.

Results

Participants discussed how lack of integration among medical and mental health service providers, lack of public transportation, and turnover in appointed government officials were barriers to integrated HIV and SUD treatment. Federal funding for support services for HIV patients was a facilitator. The Affordable Care Act has limited impact in Puerto Rico because provisions related to health insurance reform do not apply to U.S. territories.

Discussion and Conclusions

Implications for intervention design include the need to provide care coordination for services from multiple providers, who are often physically separated and working in different reimbursement systems, and the potential for mobile and patient transportation services to bridge these gaps. Continuous interaction with political leaders is needed to maintain current facilitators. These findings are relevant as the current economic crisis in Puerto Rico affects funding, and may be relevant for other settings with substance use-driven epidemics.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2174-7) contains supplementary material, which is available to authorized users.

Cost Effectiveness and Cost Containment in the Era of Interferon-Free Therapies to Treat Hepatitis C Virus Genotype 1

Background

Interferon-free regimens to treat hepatitis C virus (HCV) genotype 1 are effective but costly. At this time, payers in the United States use strategies to control costs including (1) limiting treatment to those with advanced disease and (2) negotiating price discounts in exchange for exclusivity.

Methods

We used Monte Carlo simulation to investigate budgetary impact and cost effectiveness of these treatment policies and to identify strategies that balance access with cost control. Outcomes included nondiscounted 5-year payer cost per 10000 HCV-infected patients and incremental cost-effectiveness ratios.

Results

We found that the budgetary impact of HCV treatment is high, with 5-year undiscounted costs of $1.0 billion to 2.3 billion per 10000 HCV-infected patients depending on regimen choices. Among noncirrhotic patients, using the least costly interferon-free regimen leads to the lowest payer costs with negligible difference in clinical outcomes, even when the lower cost regimen is less convenient and/or effective. Among cirrhotic patients, more effective but costly regimens remain cost effective. Controlling costs by restricting treatment to those with fibrosis stage 2 or greater disease was cost ineffective for any patient type compared with treating all patients.

Conclusions

Treatment strategies using interferon-free therapies to treat all HCV-infected persons are cost effective, but short-term cost is high. Among noncirrhotic patients, using the least costly interferon-free regimen, even if it is not single tablet or once daily, is the cost-control strategy that results in best outcomes. Restricting treatment to patients with more advanced disease often results in worse outcomes than treating all patients, and it is not preferred.

Costs of Expanded Rapid HIV Testing in Four Emergency Departments

OBJECTIVE

The HIV Prevention Trials Network (HPTN) 065 trial sought to expand HIV screening of emergency department (ED) patients in Bronx, New York, and Washington, D.C. This study assessed the testing costs associated with different expansion processes and compared them with costs of a hypothetical optimized process.

METHODS

Micro-costing studies were conducted in two participating EDs in each city that switched from point-of-care (POC) to rapid-result laboratory testing. In three EDs, laboratory HIV testing was only conducted for patients having blood drawn for clinical reasons; in the other ED, all HIV testing was conducted with laboratory testing. Costs were estimated through direct observation and interviews to document process flows, time estimates, and labor and materials costs. A hypothetical optimized process flow used minimum time estimates for each process step. National wage and fringe rates and local reagent costs were used to determine the average cost (excluding overhead) per completed nonreactive and reactive test in 2013 U.S. dollars.

RESULTS

Laboratory HIV testing costs in the EDs ranged from $17.00 to $23.83 per completed nonreactive test, and POC testing costs ranged from $17.64 to $37.60; cost per completed reactive test ranged from $89.29 to $123.17. Costs of hypothetical optimized HIV testing with automated process steps were approximately 45% lower for nonreactive tests and 20% lower for reactive tests. The cost per ED visit to conduct expanded HIV testing in each hospital ranged from $1.21 to $3.96.

CONCLUSION

An optimized process could achieve additional cost savings but would require an investment in electronic system interfaces to further automate testing processes.

The cost-effectiveness of sofosbuvir-based regimens for treatment of hepatitis C virus genotype 2 or 3 infection

BACKGROUND

Chronic infection with hepatitis C virus (HCV) genotype 2 or 3 can be treated with sofosbuvir without interferon. Because sofosbuvir is costly, its benefits should be compared with the additional resources used.

OBJECTIVE

To estimate the cost-effectiveness of sofosbuvir-based treatments for HCV genotype 2 or 3 infection in the United States.

DESIGN

Monte Carlo simulation, including deterministic and probabilistic sensitivity analyses.

DATA SOURCES

Randomized trials, observational cohorts, and national health care spending surveys.

TARGET POPULATION

8 patient types defined by HCV genotype (2 vs. 3), treatment history (naive vs. experienced), and cirrhosis status (noncirrhotic vs. cirrhotic).

TIME HORIZON

Lifetime.

PERSPECTIVE

Payer.

INTERVENTION

Sofosbuvir-based therapies, pegylated interferon-ribavirin, and no therapy.

OUTCOME MEASURES

Discounted quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs).

RESULTS OF BASE-CASE ANALYSIS

The ICER of sofosbuvir-based treatment was less than $100,000 per QALY in cirrhotic patients (genotype 2 or 3 and treatment-naive or treatment-experienced) and in treatment-experienced noncirrhotic patients but was greater than $200,000 per QALY in treatment-naive noncirrhotic patients.

RESULTS OF SENSITIVITY ANALYSIS

The ICER of sofosbuvir-based therapy for treatment-naive noncirrhotic patients with genotype 2 or 3 infection was less than $100,000 per QALY when the cost of sofosbuvir was reduced by approximately 40% and 60%, respectively. In probabilistic sensitivity analyses, cost-effectiveness conclusions were robust to uncertainty in treatment efficacy.

LIMITATION

The analysis did not consider possible benefits of preventing HCV transmission.

CONCLUSION

Sofosbuvir provides good value for money for treatment-experienced patients with HCV genotype 2 or 3 infection and those with cirrhosis. At their current cost, sofosbuvir-based regimens for treatment-naive noncirrhotic patients exceed willingness-to-pay thresholds commonly cited in the United States.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse and National Institute of Allergy and Infectious Diseases.

Cost-effectiveness of rapid hepatitis C virus (HCV) testing and simultaneous rapid HCV and HIV testing in substance abuse treatment programs

AIMS

To evaluate the cost-effectiveness of rapid hepatitis C virus (HCV) and simultaneous HCV/HIV antibody testing in substance abuse treatment programs.

DESIGN

We used a decision analytic model to compare the cost-effectiveness of no HCV testing referral or offer, off-site HCV testing referral, on-site rapid HCV testing offer and on-site rapid HCV and HIV testing offer. Base case inputs included 11% undetected chronic HCV, 0.4% undetected HIV, 35% HCV co-infection among HIV-infected, 53% linked to HCV care after testing antibody-positive and 67% linked to HIV care. Disease outcomes were estimated from established computer simulation models of HCV [Hepatitis C Cost-Effectiveness (HEP-CE)] and HIV [Cost-Effectiveness of Preventing AIDS Complications (CEPAC)].

SETTING AND PARTICIPANTS

Data on test acceptance and costs were from a national randomized trial of HIV testing strategies conducted at 12 substance abuse treatment programs in the United States.

MEASUREMENTS

Lifetime costs (2011 US$) and quality-adjusted life years (QALYs) discounted at 3% annually; incremental cost-effectiveness ratios (ICERs).

FINDINGS

On-site rapid HCV testing had an ICER of $18,300/QALY compared with no testing, and was more efficient than (dominated) off-site HCV testing referral. On-site rapid HCV and HIV testing had an ICER of $64,500/QALY compared with on-site rapid HCV testing alone. In one- and two-way sensitivity analyses, the ICER of on-site rapid HCV and HIV testing remained <$100,000/QALY, except when undetected HIV prevalence was <0.1% or when we assumed frequent HIV testing elsewhere. The ICER remained <$100,000/QALY in 91% of probabilistic sensitivity analyses.

CONCLUSIONS

On-site rapid hepatitis C virus and HIV testing in substance abuse treatment programs is cost-effective at a <$100,000/quality-adjusted life year threshold.

The hepatitis C cascade of care: identifying priorities to improve clinical outcomes

BACKGROUND

As highly effective hepatitis C virus (HCV) therapies emerge, data are needed to inform the development of interventions to improve HCV treatment rates. We used simulation modeling to estimate the impact of loss to follow-up on HCV treatment outcomes and to identify intervention strategies likely to provide good value for the resources invested in them.

METHODS

We used a Monte Carlo state-transition model to simulate a hypothetical cohort of chronically HCV-infected individuals recently screened positive for serum HCV antibody. We simulated four hypothetical intervention strategies (linkage to care; treatment initiation; integrated case management; peer navigator) to improve HCV treatment rates, varying efficacies and costs, and identified strategies that would most likely result in the best value for the resources required for implementation.

MAIN MEASURES

Sustained virologic responses (SVRs), life expectancy, quality-adjusted life expectancy (QALE), costs from health system and program implementation perspectives, and incremental cost-effectiveness ratios (ICERs).

RESULTS

We estimate that imperfect follow-up reduces the real-world effectiveness of HCV therapies by approximately 75%. In the base case, a modestly effective hypothetical peer navigator program maximized the number of SVRs and QALE, with an ICER compared to the next best intervention of $48,700/quality-adjusted life year. Hypothetical interventions that simultaneously addressed multiple points along the cascade provided better outcomes and more value for money than less costly interventions targeting single steps. The 5-year program cost of the hypothetical peer navigator intervention was $14.5 million per 10,000 newly diagnosed individuals.

CONCLUSIONS

We estimate that imperfect follow-up during the HCV cascade of care greatly reduces the real-world effectiveness of HCV therapy. Our mathematical model shows that modestly effective interventions to improve follow-up would likely be cost-effective. Priority should be given to developing and evaluating interventions addressing multiple points along the cascade rather than options focusing solely on single points.

Cost-effectiveness of blood donor screening for Babesia microti in endemic regions of the United States

BACKGROUND

Babesia microti is the leading reported cause of red blood cell (RBC) transfusion-transmitted infection in the United States. Donor screening assays are in development.

STUDY DESIGN AND METHODS

A decision analytic model estimated the cost-effectiveness of screening strategies for preventing transfusion-transmitted babesiosis (TTB) in a hypothetical cohort of transfusion recipients in Babesia-endemic areas of the United States. Strategies included: 1) no screening; 2) Uniform Donor Health History Questionnaire (UDHQ), "status quo"; 3) recipient risk targeting using donor antibody and polymerase chain reaction (PCR) screening; 4) universal endemic donor antibody screening; and 5) universal endemic donor antibody and PCR screening. Outcome measures were TTB cases averted, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs; $/QALY). We assumed a societal willingness to pay of $1 million/QALY based on screening for other transfusion-transmitted infections.

RESULTS

Compared to no screening, the UDHQ avoids 0.02 TTB cases per 100,000 RBC transfusions at an ICER of $160,000/QALY whereas recipient risk-targeted strategy using antibody/PCR avoids 1.62 TTB cases per 100,000 RBC transfusions at an ICER of $713,000/QALY compared to the UDHQ. Universal endemic antibody screening avoids 3.39 cases at an ICER of $760,000/QALY compared to the recipient risk-targeted strategy. Universal endemic antibody/PCR screening avoids 3.60 cases and has an ICER of $8.8 million/QALY compared to universal endemic antibody screening. Results are sensitive to blood donor Babesia prevalence, TTB transmission probability, screening test costs, risk and severity of TTB complications, and impact of babesiosis diagnosis on donor quality of life.

CONCLUSION

Antibody screening for Babesia in endemic regions is appropriate from an economic perspective based on the societal willingness to pay for preventing infectious threats to blood safety.

The cost-effectiveness of rapid HIV testing in substance abuse treatment: results of a randomized trial

BACKGROUND

The President's National HIV/AIDS Strategy calls for coupling HIV screening and prevention services with substance abuse treatment programs. Fewer than half of US community-based substance abuse treatment programs make HIV testing available on-site or through referral.

METHODS

We measured the cost-effectiveness of three HIV testing strategies evaluated in a randomized trial conducted in 12 community-based substance abuse treatment programs in 2009: off-site testing referral, on-site rapid testing with information only, on-site rapid testing with risk-reduction counseling. Data from the trial included patient demographics, prior testing history, test acceptance and receipt of results, undiagnosed HIV prevalence (0.4%) and program costs. The Cost-Effectiveness of Preventing AIDS Complications (CEPAC) computer simulation model was used to project life expectancy, lifetime costs, and quality-adjusted life years (QALYs) for HIV-infected individuals. Incremental cost-effectiveness ratios (2009 US $/QALY) were calculated after adding costs of testing HIV-uninfected individuals; costs and QALYs were discounted at 3% annually.

RESULTS

Referral for off-site testing is less efficient (dominated) compared to offering on-site testing with information only. The cost-effectiveness ratio for on-site testing with information is $60,300/QALY in the base case, or $76,300/QALY with 0.1% undiagnosed HIV prevalence. HIV risk-reduction counseling costs $36 per person more without additional benefit.

CONCLUSIONS

A strategy of on-site rapid HIV testing offer with information only in substance abuse treatment programs increases life expectancy at a cost-effectiveness ratio <$100,000/QALY. Policymakers and substance abuse treatment leaders should seek funding to implement on-site rapid HIV testing in substance abuse treatment programs for those not recently tested.

HIV rapid testing in substance abuse treatment: implementation following a clinical trial

The Substance Abuse Mental Health Services Administration has promoted HIV testing and counseling as an evidence-based practice. Nevertheless, adoption of HIV testing in substance abuse treatment programs has been slow. This article describes the experience of a substance abuse treatment agency where, following participation in a clinical trial, the agency implemented an HIV testing and counseling program. During the trial, a post-trial pilot, and early implementation the agency identified challenges and developed strategies to overcome barriers to adoption of the intervention. Their experience may be instructive for other treatment providers seeking to implement an HIV testing program. Lessons learned encompassed the observed acceptability of testing and counseling to clients, the importance of a "champion" and staff buy-in, the necessity of multiple levels of community and agency support and collaboration, the ability to streamline staff training, the need for a clear chain of command, the need to develop program specific strategies, and the requirement for sufficient funding. An examination of costs indicated that some staff time may not be adequately reimbursed by funding sources for activities such as adapting the intervention, start-up training, ongoing supervision and quality assurance, and overhead costs.

Optimising the care of patients with cirrhosis and gastrointestinal haemorrhage: a quality improvement study

BACKGROUND

Patients with cirrhosis and gastrointestinal haemorrhage are a complex group with high thirty-day mortality rates.

AIM

To evaluate the quality of care delivered to patients admitted with gastrointestinal (GI) haemorrhage to a tertiary care centre before and after implementing a quality improvement initiative for better adherence to practice standards.

METHODS

This is a prospective cohort study. All patients admitted to a tertiary care centre with a GI haemorrhage and known or suspected chronic liver disease were evaluated before and after the quality improvement initiative was implemented. Interventions to improve quality of care included the delivery of educational sessions for medical practitioners, and creation and implementation of standardised admission order sets. Quality of care measures included delivery of prophylactic antibiotics (PAs) within 24 h of admission, delivery of a somatostatin analogue (SA) and use of a proton pump inhibitor (PPI); optimal care was defined as receiving all three. Secondary outcomes included hospital length of stay (LOS) and 30-day readmission rate.

RESULTS

In comparing the preintervention and postintervention groups, we found significant gains in delivering PAs (57% vs. 75%, P=0.05), SAs (54% vs. 76%, P=0.013) and overall optimal care (41% vs. 65%, P=0.008). Use of PPIs did not change and remained in accordance with guidelines (90% vs. 87%, P=0.67). Hospital LOS remained similar between the two groups (6.8 vs. 7.1, P=0.88), whereas the 30-day readmission decreased (41% vs. 13%, P=0.001).

CONCLUSION

Implementation of quality improvement initiatives, such as targeted educational efforts and standardised order sets, can improve the quality of care delivered and patient outcomes in patients with cirrhosis and GI haemorrhage.

Comparing academic and community-based hospitalists

In 2006, hospitalist programs were formally introduced at both an academic and community hospital in the same city providing an opportunity to study the similarities and differences in workflows in these two settings. The data were collected using a time-flow methodology allowing the two workflows to be compared quantitatively. The results showed that the hospitalists in the two settings devoted similar proportions of their workday to the task categories studied. Most of the time was spent providing indirect patient care followed by direct patient care, travel, personal, and other. However, after adjusting for patient volumes, the data revealed that academic hospitalists spent significantly more time per patient providing indirect patient care (Academic: 54.7 +/- 11.1 min/patient, Community: 41.9 +/- 9.8 min/patient, p < 0.001). Additionally, we found that nearly half of the hospitalists' time at both settings was spent multitasking. Although we found subtle workflow differences between the academic and community programs, their similarities were more striking as well as greater than their differences. We attribute these small differences to the higher case mix index at the academic program as well greater complexity and additional communication hand-offs inherent to a tertiary academic medical center. It appears that hospitalists, irrespective of their work environment, spend far more time documenting, communicating and coordinating care than they do at the bedside raising the question, is this is a necessary feature of the hospitalist care model or should hospitalists restructure their workflow to improve outcomes?

Review of complications in a series of patients with known gastro-esophageal varices undergoing transesophageal echocardiography

BACKGROUND

The presence of gastroesophageal varices is considered a relative contraindication to performing transesophageal echocardiography (TEE), but this is based on expert opinion, and there is limited data to support this recommendation. The aim of this study was to review the complications and benefit of performing TEE in patients with known gastroesophageal varices.

METHODS

Fourteen patients with known esophageal varices who underwent TEE from 1997 to 2007 were identified. Patients' charts were reviewed for procedure-related complications as well as benefit in performing TEE.

RESULTS

The 14 patients had an average age of 50.4 years. Six patients had grade 2 esophageal varices at the time of TEE. The most common etiology of portal hypertension was alcoholic liver disease (11 of 14), and the most common indication for TEE was to rule out endocarditis (11 of 14). There were no major bleeding or other complications noted. All 14 procedures were able to provide the clinical information requested.

CONCLUSION

Although the presence of known esophageal varices was previously thought to be a contraindication to performing TEE, the results of this study show that TEE without transgastric views can be performed without serious complications in patients with grade 1 or 2 esophageal varices who have not experienced recent variceal hemorrhages. Additionally, there is a definite benefit, as all of the clinical questions were successfully answered.

Randomised controlled trial of montelukast plus inhaled budesonide versus double dose inhaled budesonide in adult patients with asthma

BACKGROUND

Inhaled corticosteroids (ICS) affect many inflammatory pathways in asthma but have little impact on cysteinyl leukotrienes. This may partly explain persistent airway inflammation during chronic ICS treatment and failure to achieve adequate asthma control in some patients. This double blind, randomised, parallel group, non-inferiority, multicentre 16 week study compared the clinical benefits of adding montelukast to budesonide with doubling the budesonide dose in adults with asthma.

METHODS

After a 1 month single blind run in period, patients inadequately controlled on inhaled budesonide (800 microg/day) were randomised to receive montelukast 10 mg + inhaled budesonide 800 microg/day (n=448) or budesonide 1600 microg/day (n=441) for 12 weeks.

RESULTS

Both groups showed progressive improvement in several measures of asthma control compared with baseline. Mean morning peak expiratory flow (AM PEF) improved similarly in the last 10 weeks of treatment compared with baseline in both the montelukast + budesonide group and in the double dose budesonide group (33.5 v 30.1 l/min). During days 1-3 after start of treatment, the change in AM PEF from baseline was significantly greater in the montelukast + budesonide group than in the double dose budesonide group (20.1 v 9.6 l/min, p<0.001), indicating faster onset of action in the montelukast group. Both groups showed similar improvements with respect to "as needed" beta agonist use, mean daytime symptom score, nocturnal awakenings, exacerbations, asthma free days, peripheral eosinophil counts, and asthma specific quality of life. Both montelukast + budesonide and double dose budesonide were generally well tolerated.

CONCLUSION

The addition of montelukast to inhaled budesonide is an effective and well tolerated alternative to doubling the dose of inhaled budesonide in adult asthma patients experiencing symptoms and inadequate control on budesonide alone.

Analysis of montelukast in mild persistent asthmatic patients with near-normal lung function

Few studies have specifically evaluated controller therapy in patients with mild persistent asthma. We used a subgroup analysis to investigate the effects of montelukast, a potent cysteinyl leukotriene receptor antagonist, on adult patients on the milder end of the asthma severity spectrum. We have identified seven double-blind, randomized, placebo-controlled studies of adult patients with mild-to-moderate chronic asthma in which montelukast was investigated. Subsets of patients with baseline forced expiratory volume in 1 sec (FEV1) > 80% and > 75% predicted or further restricted by less than daily rescue beta-agonist use were included as four cohorts (A, B, C, D), and efficacy measures, including change in FEV1 rescue-free days, beta-agonist use, nocturnal awakenings and blood eosinophil counts were evaluated. Cohorts A to D comprised 21%, 8%, 11%, and 4%, respectively, of patients from these studies. Mean pretreatment FEV1 ranged from 81% to 84% predicted and daily beta-agonist use from 2.4 to 4.5 puffs day(-1) in the four cohorts. Pooled results demonstrated a treatment effect for montelukast over placebo in all cohorts, for all endpoints. There was a significant improvement in FEV1 in montelukast-treated patients (7-8% over baseline) compared with placebo (1-4% over baseline, between-group difference P < or = 0.02) for all cohorts. Similarly, the percentage of rescue-free days increased substantially more with montelukast (22-30%) than with placebo (8-13%). This subgroup analysis indicates that montelukast produced improvements in parameters of asthma control in patients with milder persistent asthma that should be confirmed in additional prospective trials.

Montelukast added to budesonide in children with persistent asthma: a randomized, double-blind, crossover study

OBJECTIVE

We tested the hypothesis that adding montelukast to budesonide would improve asthma control in children with inhaled glucocorticoid-dependent persistent asthma.

STUDY DESIGN

In a multicenter, randomized, double-blind, crossover study, we compared the benefit of adding montelukast, 5 mg, or placebo once daily to budesonide, 200 microg, twice daily.

RESULTS

After a 1-month run-in with budesonide, 200 microg, twice daily, 279 children were randomized to montelukast or placebo. The mean +/- SD age was 10.4 +/- 2.2 years, the mean forced expiratory volume in 1 second (FEV(1)) was 77.7% +/- 10.6% predicted, and reversibility was 18.1% +/- 12.9%. Compared with adding placebo to budesonide, adding montelukast produced significant improvements in mean percent change from baseline FEV(1) (P =.062 [P =.010 for per-protocol analysis]), mean absolute change from baseline FEV(1) (P =.040), mean increase from baseline in morning (P =.023) and evening (P =.012) peak expiratory flows, decrease in exacerbation days by approximately 23% (P <.001), decreased beta2-agonist use (P =.013), and reduced blood eosinophil counts (P <.001). The treatments did not differ significantly with regard to safety.

CONCLUSIONS

Montelukast, 5 mg, added to budesonide improved asthma control significantly, indicated by a small additive effect on lung function and a clinically relevant decrease in asthma exacerbation days.

Oral montelukast versus inhaled beclomethasone in 6- to 11-year-old children with asthma: results of an open-label extension study evaluating long-term safety, satisfaction, and adherence with therapy

This 6-month, open-label extension study of a previously described base study compared oral montelukast with inhaled beclomethasone in terms of safety, forced expiratory volume in one second (FEV1) measurements, parent and patient satisfaction with treatment, asthma-related medical resource utilization, school absenteeism, and parental work loss in children with asthma. A total of 124 of 266 asthmatic children, 6 to 11 years of age, who enrolled in the base study entered a 6-month open-label extension study (74 boys, 50 girls) and were re-randomized (2:1 ratio) to receive once-daily oral montelukast (n = 83) or inhaled beclomethasone 100 mcg three times daily (n = 41). Children were evaluated in the clinic prior to re-randomization (Month 0) and at regular visits at 1, 3, and 6 months. Children and their parents showed a significantly higher overall satisfaction for montelukast at 6 months than for inhaled beclomethasone (p = 0.001 and p < 0.05, respectively). According to parents, montelukast was more convenient (p < 0.001), less difficult to use (p = 0.005), and was used as instructed more of the time (p = 0.006) compared with beclomethasone. Oral corticosteroid use was similar in the montelukast (13% of patients) and beclomethasone (17%) treatment groups. The montelukast treatment group was more adherent with their regimen than the inhaled beclomethasone treatment group; almost twice as many children on montelukast compared with inhaled beclomethasone were highly compliant (82% versus 45%). The two study groups were similar with respect to overall safety, change in FEV1, asthma-related medical resource utilization, school absenteeism, and parental work loss. Montelukast represents a safe and effective asthma treatment regimen to which children with asthma are more likely to adhere.

Montelukast or salmeterol combined with an inhaled steroid in adult asthma: design and rationale of a randomized, double-blind comparative study (the IMPACT Investigation of Montelukast as a Partner Agent for Complementary Therapy-trial)

Asthma patients who continue to experience symptoms despite taking regular inhaled corticosteroids represent a management challenge. Leukotrienes play a key role in asthma pathophysiology, and since pro-inflammatory leukotrienes are poorly suppressed by corticosteroids it seems rational to add a leukotriene receptor antagonist (LTRA) when a low to moderate dose of inhaled corticosteroids does not provide sufficient disease control. Long acting beta2-agonist (LABA) treatment represents an alternative to LTRAs and both treatment modalities have been shown to provide additional disease control when added to corticosteroid treatment. To compare the relative clinical benefits of adding either a LTRA or a LABA to asthma patients inadequately controlled by inhaled corticosteroids, a randomized, double-blind, multi-centre, 48-week study will be initiated at approximately 120 centres throughout Europe, Latin America, Middle East, Africa and the Asia-Pacific region in early 2000. The study will compare the oral LTRA montelukast with the inhaled LABA salmeterol, each administered on a background of inhaled fluticasone, on asthma attacks, quality of life, lung function, eosinophil levels, healthcare utilization, and safety, in approximately 1200 adult asthmatic patients. The requirements for study enrollment include a history of asthma, FEV1 or PEFR values between 50% and 90% of the predicted value together with > or = 12% improvement in FEV1 after beta-agonist administration, a minimum pre-determined level of asthma symptoms and daily beta-agonist medication. The study will include a 4-week run-in period, during which patients previously taking inhaled corticosteroids are switched to open-label fluticasone (200 microg daily), followed by a 48-week double-blind, treatment period in which patients continuing to experience abnormal pulmonary function and daytime symptoms are randomized to receive montelukast (10 mg once daily) and salmeterol placebo, or inhaled salmeterol (100 microg daily) and montelukast placebo. All patients will continue with inhaled fluticasone (200 microg daily). During the study, asthma attacks, overnight asthma symptoms, and morning peak expiratory flow rate will be assessed using patient diary cards; quality of life will also be assessed using an asthma-specific quality-of life questionnaire. The results of this study are expected to provide physicians with important clinical evidence to help them make a rational and logical treatment choice for asthmatic patients experiencing breakthrough symptoms on inhaled corticosteroids.

Comparison of the effects of intravenous and oral montelukast on airway function: a double blind, placebo controlled, three period, crossover study in asthmatic patients

BACKGROUND

Montelukast, a leukotriene receptor antagonist, improves parameters of asthma control including forced expiratory volume in one second (FEV(1)) when given orally to patients aged six years or older. This study was undertaken to compare the effect on FEV(1) of intravenous and oral montelukast and placebo during the 24 hour period following administration.

METHODS

Fifty one asthmatic patients (FEV(1) 40-80% predicted and > or =15% improvement after inhaled beta agonist) were enrolled in a double blind, single dose, three period, crossover study to receive intravenous montelukast (7 mg), oral montelukast (10 mg), or placebo in a randomised fashion. The primary end point was area under the curve (AUC)(0-24 h) of the percentage change from baseline in FEV(1). Additional end points were maximum percentage change in FEV(1) and percentage change at different time points.

RESULTS

Compared with placebo, intravenous and oral montelukast significantly increased the AUC(0-24 h) (means of 20.70%, 15.72%, and 7.75% for intravenous, oral and placebo, respectively; no statistical difference between intravenous and oral). The difference in least square means from placebo for intravenous montelukast was 13.27% (95% CI 7.07 to 19.46), p<0.001 and for oral montelukast was 7.44% (95% CI 1.20 to 13.68), p = 0.020. The maximum percentage change in FEV(1) was not significantly different for intravenous and oral montelukast (difference in least square means 6.78% (95% CI -0.59 to 14.15), p = 0.071). The mean percentage change in FEV(1) for intravenous montelukast was greater than for oral montelukast within the first hour (15.02% vs 4.67% at 15 min, p< or =0.001; 18.43% vs 12.90% at one hour, p<0.001 for intravenous and oral montelukast, respectively (placebo 3.05% at 15 minutes, 7.33% at one hour). Intravenous and oral montelukast were similar to placebo in the frequency of adverse events.

CONCLUSIONS

The onset of action for intravenous montelukast was faster than for oral montelukast and the improvement in airway function lasted over the 24 hour observation period for both treatments. Although not well understood, there was a trend toward a greater improvement in FEV(1) with intravenous than with oral montelukast. These findings suggest that leukotriene receptor antagonists should be investigated as a treatment for acute severe asthma.

Montelukast versus salmeterol in patients with asthma and exercise-induced bronchoconstriction. Montelukast/Salmeterol Exercise Study Group

BACKGROUND

Montelukast, a leukotriene receptor antagonist, and salmeterol, a long-acting beta(2)-receptor agonist, each have demonstrated benefits in the treatment of exercise-induced bronchoconstriction (EIB) in short-term studies. Direct comparisons between these agents in long-term studies are limited.

OBJECTIVE

We sought to compare montelukast and salmeterol in the long-term treatment of EIB.

METHODS

One hundred ninety-seven patients with mild asthma and a postexercise fall in FEV(1) of at least 18% were randomized (double-blind) to receive montelukast 10 mg once daily or salmeterol 50 microg twice daily for 8 weeks. Exercise challenge was repeated at day 3, week 4, and week 8 after randomization near the end of the dosing interval for both drugs. The primary efficacy endpoint was the maximal percent fall in postexercise FEV(1) at week 8.

RESULTS

Montelukast was effective in treating EIB without inducing tolerance and provided superior (P </=.001) protection than salmeterol at weeks 4 and 8, with comparable protection at day 3. The frequency of respiratory clinical adverse events (P =.046) and discontinuations because of clinical adverse events (P =.052) were less with montelukast.

CONCLUSION

The effect of montelukast was greater than that of salmeterol in the chronic treatment of EIB over a period of 8 weeks in patients with mild asthma as demonstrated by effect size, maintenance of effect, and fewer respiratory clinical adverse events during the study period. Montelukast may be a better alternative to salmeterol as a controller agent for the chronic treatment of EIB.

Randomised, placebo controlled trial of effect of a leukotriene receptor antagonist, montelukast, on tapering inhaled corticosteroids in asthmatic patients

OBJECTIVE

To determine the ability of montelukast, a leukotriene receptor antagonist, to allow tapering of inhaled corticosteroids in clinically stable asthmatic patients.

DESIGN

Double blind, randomised, placebo controlled, parallel group study. After a single blind placebo run in period, during which (at most) two inhaled corticosteroids dose decreases occurred, qualifying, clinically stable patients were allocated randomly to receive montelukast (10 mg tablet) or matching placebo once daily at bedtime for up to 12 weeks.

SETTING

23 academic asthma centres in United States, Canada, and Europe.

PARTICIPANTS

226 clinically stable patients with chronic asthma receiving high doses of inhaled corticosteroids (113 randomised to montelukast and 113 to placebo).

INTERVENTIONS

Every 2 weeks, the inhaled corticosteroids dose was tapered, maintained, or increased (rescue) based on a standardised clinical score.

MAIN OUTCOME MEASURES

Last tolerated dose of inhaled corticosteroids.

RESULTS

Compared with placebo, montelukast allowed significant (P=0. 046) reduction in the inhaled corticosteroid dose (montelukast 47% v placebo 30%; least square mean difference 17.6%, 95% confidence interval 0.3 to 34.8). Fewer patients on montelukast (18 (16%) v 34 (30%) placebo, P=0.01) required discontinuation because of failed rescue.

CONCLUSIONS

Montelukast reduces the need for inhaled corticosteroids among patients requiring moderate to high doses of corticosteroid to maintain asthma control.

Montelukast reduces airway eosinophilic inflammation in asthma: a randomized, controlled trial

Leukotrienes are pro-inflammatory mediators which may contribute to tissue, sputum, and blood eosinophilia seen in allergic and inflammatory diseases, including asthma. Montelukast is a cysteinyl leukotriene1 (CysLT1) receptor antagonist which improves asthma control; the aim of this study was to investigate its effect on induced sputum eosinophils. Montelukast 10 mg (n=19) or placebo (n=21) were administered orally once in the evening for 4 weeks to 40 chronic adult asthmatic patients, aged 19-64 yrs, in a double-blind, randomized, parallel group study. Patients were included if, at prestudy, they had >5% sputum eosinophils, symptomatic asthma with a forced expiratory volume in one second > or =65% of the predicted value and were being treated only with "as needed" inhaled beta2-agonists. In addition to sputum eosinophils, blood eosinophils and clinical endpoints were also assessed. Four weeks of montelukast treatment decreased sputum eosinophils from 7.5% to 3.9% (3.6% decrease, 95% confidence interval (CI) -16.6-0.4). In contrast, placebo treatment was associated with an increase in sputum eosinophils from 14.5% to 17.9% (3.4% increase, 95% CI -3.5-9.8). The least squares mean difference between groups (-11.3%, 95% CI -21.1-(-1.4)) was significant (p=0.026). Compared with placebo, montelukast significantly reduced blood eosinophils (p=0.009), asthma symptoms (p=0.001) and beta2-agonist use (p<0.001) while significantly increasing morning peak expiratory flow (p=0.001). Montelukast was generally well tolerated in this study, with a safety profile similar to the placebo. These results demonstrate that montelukast decreases airway eosinophilic inflammation in addition to improving clinical parameters. Its efficacy in the treatment of chronic asthma may be due, in part, to the effect on airway inflammation.

The effect of montelukast (MK-0476), a cysteinyl leukotriene receptor antagonist, on allergen-induced airway responses and sputum cell counts in asthma

BACKGROUND

Cysteinyl leukotrienes are capable of inducing chemotaxis of eosinophils in vitro and within the airways of animals and humans in vivo.

OBJECTIVE

We hypothesized that montelukast (MK-0476), a potent cysLT1 receptor antagonist, would protect against allergen-induced early (EAR) and late (LAR) asthmatic responses by virtue of anti-inflammatory properties. Hence, we studied the effect of pretreatment with oral montelukast on allergen-induced airway responses. As an exploratory endpoint, changes in inflammatory cell differentials and eosinophil cationic protein (ECP) were evaluated in hypertonic saline-induced sputum.

METHODS

Twelve asthmatic men (20-34 years, FEV1 79-109% predicted, histamine PC20FEV1 <4 mg/mL) with dual responses to inhaled house dust mite extract participated in a two-period, double-blind, placebo-controlled, crossover study. Three oral doses of montelukast (10 mg) or matching placebo were administered 36 and 12 h before, and 12 h post-allergen. The airway response to allergen was measured by FEV1, and the EAR and LAR were expressed as the corresponding areas under the time-response curves (AUC0-3 h and AUC3-8h, respectively). During each study period, sputum was induced with 4.5% NaCl 24 h before and 24 h after a standardized allergen challenge. Processed whole sputum cytospins were stained with Giemsa, and cell counts expressed as percentage nonsquamous cells. ECP was measured by FEIA in sputum supernatants.

RESULTS

All subjects completed the study. The changes in baseline FEV1 were not significantly different between the two pretreatments (P = 0.183). Montelukast significantly inhibited the EAR and LAR, reducing the AUC0-3h by 75.4% (P<0.001) and the AUC3-8h by 56.9% (P = 0.003) as compared with placebo. Sputa of nine subjects could be included in the analysis (<80% squamous cells). Allergen challenge significantly increased sputum eosinophils after placebo (mean change +/- SD: 4.8 +/- 5.8%, P = 0.038), with a similar trend after montelukast (mean change +/- SD: 4.1 +/- 5.4%; P = 0.056). The allergen-induced changes in sputum eosinophils and ECP, however, were not significantly different between the two pretreatments (P = 0.652 and P = 0.506, respectively).

CONCLUSION

We conclude that oral montelukast protects against allergen-induced early and late airway responses in asthma. However, using the present dosing and sample size, this protection was not accompanied with changes in sputum eosinophil percentage or activity, which may require more prolonged pretreatment with cysLT1 receptor antagonists.

Leukotriene modifiers as novel therapeutics in asthma

After years of research, the components of slow-reacting substance of anaphylaxis have been identified as the cysteinyl leukotrienes C4, D4, and E4. Leukotrienes are now known to be important mediators of chronic asthma. Leukotrienes cause bronchoconstriction, oedema, and mucus secretion in models of asthma and are produced in excess quantities in asthmatic patients. Leukotriene receptor antagonists and biosynthesis inhibitors have been produced to improve the signs and symptoms of asthma. These agents block laboratory challenges simulating chronic asthma such as exercise, allergen, and aspirin challenge. They also are effective in studies of chronic asthma in a wide variety of patient types demonstrating that leukotrienes are indeed important mediators of asthma. Over the next several years the appropriate place in asthma therapy for these new agents will be defined.

Montelukast, a leukotriene-receptor antagonist, for the treatment of mild asthma and exercise-induced bronchoconstriction

BACKGROUND

Patients with mild asthma frequently have only exercise-induced bronchoconstriction, a symptom of inadequate control of asthma. We evaluated the ability of montelukast, a leukotriene-receptor antagonist, to protect such patients against exercise-induced bronchoconstriction.

METHODS

We randomly assigned 110 patients (age, 15 to 45 years) with mild asthma and a decrease in the forced expiratory volume in one second (FEV1) of at least 20 percent after exercise on two occasions during a placebo run-in period to receive 10 mg of montelukast (54 patients) or placebo (56 patients) once daily at bedtime for 12 weeks in a double-blind study. Treatment was followed by a two-week, single-blind washout period during which all patients received placebo. Exercise challenges were performed at base line; 20 to 24 hours after dosing at weeks 4, 8, and 12; and at the end of the washout period. The primary end point was the area under the curve for FEV1 (expressed as the percent change from base-line values) in the first 60 minutes after exercise. This measure summarized the extent and duration of bronchoconstriction after exercise.

RESULTS

At 12 weeks, montelukast therapy offered significantly greater protection against exercise-induced bronchoconstriction than placebo therapy (expressed as the percentage of inhibition of the end points), as evidenced by the improvement in the area under the FEV1 curve (degree of inhibition, 47.4 percent; P=0.002). Montelukast therapy was also associated with a significant improvement in the maximal decrease in FEV1 after exercise (P=0.003) and the time from the maximal decrease in FEV1 to the return of lung function to within 5 percent of pre-exercise values (P=0.04). The differences between groups in the various measures of lung function were similar at 4, 8, and 12 weeks; there was no evidence of rebound worsening of lung function in the montelukast group after the washout period. After 12 weeks of treatment, patients in the montelukast group were more likely to rate their asthma control as better and less likely to require rescue therapy with a beta-agonist during or after exercise challenge. The rates of adverse events were similar in the two groups.

CONCLUSIONS

As compared with placebo, once-daily treatment with montelukast provided significant protection against exercise-induced asthma over a 12-week period. Tolerance to the medication and rebound worsening of lung function after discontinuation of treatment were not seen.

Lisofylline prevents leak, but not neutrophil accumulation, in lungs of rats given IL-1 intratracheally

Interleukin-1 (IL-1) is increased in lung lavages from patients with the acute respiratory distress syndrome, and administering IL-1 intratracheally causes neutrophil accumulation and a neutrophil-dependent oxidative leak in lungs of rats. In the present study, we found that rats pretreated intraperitoneally with lisofylline [(R)-1-(5-hydroxyhexyl)-3, 7-dimethylxanthine (LSF)], an inhibitor of lysophosphatidic acid acyl transferase, which reduces the production of unsaturated phosphatidic acid species, did not develop the lung leak or the related ultrastructural abnormalities that occur after intratracheal administration of IL-1. However, rats pretreated with LSF and then given IL-1 intratracheally did develop the same elevations of lung lavage cytokine-induced neutrophil chemoattractant (CINC) levels and the same increased numbers of lung lavage neutrophils as rats given IL-1 intratracheally. Lungs of rats given IL-1 intratracheally also had increased unsaturated phosphatidic acid and free acyl (linoleate, linolenate) concentrations compared with untreated rats, and these lipid responses were prevented by pretreatment of LSF. Our results reveal that LSF decreases lung leak and lung lipid alterations without decreasing neutrophil accumulation or lung lavage CINC increases in rats given IL-1 intratracheally.

Pharmacokinetics, bioavailability, and safety of montelukast sodium (MK-0476) in healthy males and females

PURPOSE

The safety, tolerability, and pharmacokinetics of intravenous *i.v.) montelukast sodium (Singulair, MK-0476), and the oral bioavailability of montelukast sodium in healthy males and healthy females were studied.

METHODS

This was a two-part study. Part I was a four-period study in males of rising i.v. doses of montelukast sodium (3, 9, and 18 mg) administered as 15-minute constant-rate i.v. infusions (Periods 1-3), followed by a 10-mg oral tablet dose of montelukast sodium (Period 4) under fasting conditions. Part II was a four-period study in females of i.v. montelukast sodium (9 mg) infused over 15 and 5 minutes (Periods 5 and 6, respectively) or injected as a bolus over 2 minutes (Period 7), followed by a 10-mg oral tablet dose of montelukast sodium (Period 8). Plasma samples were collected and analyzed by HPLC.

RESULTS

In males (N = 6), as the i.v. dose of montelukast sodium increased from 3 to 18 mg, the area under the plasma concentration-time curve of montelukast sodium from time 0 to infinity (AUC) increased proportionately. The mean values of plasma clearance (CL), steady-state volume of distribution (Vss), plasma terminal half-life (t1/12), and mean residence time in the body (MRTi.v.) of montelukast sodium were 45.5 ml/min, 10.5 1, 5.1 hr, and 3.9 hr, respectively, and remained essentially constant over the i.v. dosage range. Following oral administration of a 10-mg tablet of montelukast sodium, the AUC, maximum plasma concentration (Cmax), time when Cmax occurred (Tmax), apparent t1/12, mean absorption time (MAT), and bioavailability (F) of montelukast sodium averaged 2441 ng.hr/ml, 385 ng/ml. 3.7 hr, 4.9 hr, 3.4 hr, and 66%, respectively. Following i.v. administration of 9 mg of montelukast sodium to females (N = 6), the values of CL, Vss, t1/2, and MRT i.v. averaged 47.6 ml/min, 9.6 1, 4.5 hr, and 3.6 hr, respectively. Following oral administration of a 10-mg tablet to females, the mean AUC, Cmax, Tmax, apparent t1/2, MAT and F were 2270 ng.hr/ml, 350 ng/ml, 3.3 hr, 4.4 hr, 2.6 hr, and 58%, respectively. These parameter values were similar to or slightly smaller than those in healthy males receiving the same i.v. and oral doses.

CONCLUSIONS

The disposition kinetics of montelukast sodium were linear. Gender had little or no effect on the kinetics of montelukast sodium. Safety results from this study indicate that intravenous doses of montelukast sodium from 3 to 18 mg and a 10-mg oral dose are well tolerated.

Pulmonary capillaritis and diffuse alveolar hemorrhage. A primary manifestation of polymyositis

Polymyositis is often complicated by either usual interstitial pneumonitis, diffuse alveolar damage, cellular interstitial pneumonitis, or bronchiolitis obliterans-organizing pneumonia. Pulmonary capillaritis, a distinct interstitial reaction associated with diffuse alveolar hemorrhage, occurs with the systemic vasculitides and some collagen vascular diseases. It has not been described in patients with polymyositis. We describe two patients who developed a relatively acute onset of polymyositis based on the appearance of a severe proximal myopathy, elevated serum creatine phosphokinase levels, compatible electromyographic abnormalities, inflammatory muscle biopsies, and in one case, the presence of serum anti-Jo-1 antibodies. Concomitant with their muscle disease, they developed respiratory failure that proved to be pulmonary capillaritis with varying degrees of diffuse alveolar hemorrhage as well as bronchiolitis obliterans-organizing pneumonia. Although those reactions are reported to occur with other collagen vascular diseases, these two cases are the first reports of pulmonary capillaritis and diffuse alveolar hemorrhage complicating polymyositis.

Effect of vitamin E deficiency and supercritical fluid aerosolized vitamin E supplementation on interleukin-1-induced oxidative lung injury in rats

We hypothesized that alterations in lung vitamin E levels would impact the development of acute oxidative lung injury. We found that dietary induced deficiency of vitamin E diminished lung tissue levels of vitamin E and increased lung leak following intratracheal administration of interleukin-1 (IL-1) to rats. Conversely, rats administered vitamin E directly to the lungs as an inhaled aerosol (0.3-3 microns particles) formed by supercritical fluid aerosolization (SFA) had increased lung tissue vitamin E levels and decreased IL-1 induced lung leak compared to control rats. Lung myeloperoxidase (MPO) activities, reflecting neutrophil concentrations, were increased in rats given IL-1 intratracheally compared to rats given saline intratracheally but were not different for control or vitamin E depleted rats. Lung MPO activities in rats given IL-1 intratracheally were slightly higher in SFA vitamin E treated rats than in control rats. Our results suggest that vitamin E levels affect susceptibility to IL-1 induced, neutrophil-dependent lung injury. We speculate that supercritical fluid aerosol (SFA) delivery of vitamin E can rapidly increase lung vitamin E levels and decrease acute oxidative lung injury.

Catalase and hydrogen peroxide cytotoxicity in cultured cardiac myocytes

We examined the role of intracellular catalase activity in modulating hydrogen peroxide (H2O2)-induced cytotoxicity in cultured chick embryo cardiac myocytes. Injury was quantitated by release of lactate dehydrogenase (LDH). Application of 1.5 mM H2O2 to myocytes caused LDH release beginning at 2 h. Inactivation or inhibition of catalase with aminotriazole or sodium azide increased LDH release but did not cause earlier release. Free catalase which entered or became associated with myocytes, but not catalase bound to agarose beads, which did not enter or become associated with myocytes, was protective. Separate experiments demonstrated that myocyte catalase activity decreased by 27% between 1 and 4 h of H2O2 exposure. Treatment with aprotinin, a protease inhibitor, prevented the H2O2-induced fall in catalase activity at 4 h but treatment with deferoxamine, an iron chelator, had no effect on catalase activity. Thus, with exposure of cardiac myocytes to H2O2, the magnitude of the cytotoxicity is modulated by endogenous or cell associated exogenous catalase. It is proposed that in addition to excessive accumulation of H2O2, a reduction intracellular catalase activity may be required before substantial cell injury occurs during H2O2 exposure. Activation of proteases may cause the reduction in catalase activity in this setting.

Interleukin-1 beta-induced neutrophil recruitment and acute lung injury in hamsters

Administering recombinant interleukin-1 beta (IL-1 beta) intratracheally caused lung neutrophil accumulation and lung injury in hamsters. The percentage of leukocytes that were neutrophils increased progressively in lavages from lungs of hamsters given 25, 50, or 100 ng IL-1 beta intratracheally 2 h before. Lung injury, reflected by increased lung lavage protein concentrations and lung lavage hemoglobin concentrations, increased 2 h after administering 100 ng IL-1 beta. Lung injury, reflected by lung wet weight/body weight ratios, followed similar patterns, with significant increases occurring 2 h after insufflating 50 or 100 ng IL-1. Our results indicate that increased concentrations of IL-1 beta in lung airways can cause neutrophil recruitment and lung injury in hamsters. This mechanism may contribute to the development of lung neutrophil accumulation and lung injury that characterizes ARDS patients who have increased airway levels of IL-1 beta.

Interleukin-1 pretreatment prevents interleukin-1-induced lung leak in rats

We found that rats pretreated with interleukin-1 (IL-1) intraperitoneally did not develop the acute oxidative, neutrophil-dependent lung leak that occurs after administration of IL-1 intratracheally (IL-1-induced tolerance). IL-1-pretreated rats also had increased lung catalase and glucose-6-phosphate dehydrogenase (G6PDH) activity and increased plasma catalase activity compared with sham-pretreated rats. In contrast to reducing lung leak, IL-1 pretreatment did not reduce the numbers of neutrophils that are increased in lung lavages of rats given IL-1 intratracheally. IL-1-induced tolerance to IL-1-mediated lung leak and the associated increases in lung catalase, lung G6PDH, and serum catalase activities were all prevented by treating rats with the IL-1-receptor antagonist or with N-acetyl-L-cysteine, an agent that increases intracellular glutathione levels. Our results indicate that IL-1 pretreatment confers tolerance to IL-1-mediated lung leak without decreasing IL-1-induced increases in lung neutrophils. The possible protective actions of IL-1 should be considered in experiments and clinical trials where IL-1 activity is reduced pharmacologically.

Post-insult treatment with interleukin-1 receptor antagonist decreases oxidative lung injury in rats given intratracheal interleukin-1

Systemic administration of recombinant human interleukin-1 receptor antagonist (IL-1Ra) caused a rapid and sustained elevation of plasma IL-1Ra levels and decreased the leak of intravascularly injected 125I-labeled albumin into lungs of rats given human recombinant interleukin-1 intratracheally. IL-1Ra treatment decreased leak when given 0.5 h before, 1.25 h after, or 2.5 h after IL-1 administration. Similarly, IL-1Ra treatment decreased lavage leukocytes and neutrophils when given 0.5 h before, 1.25 h after, or 2.5 h after IL-1 administration. Pretreatment with IL-1Ra also decreased lung myeloperoxidase activity and breath H2O2 concentration increases in rats given IL-1 intratracheally. Our results suggest that IL-1Ra treatment may decrease acute lung injury and neutrophil influx even when given after an IL-1 inciting insult.