Trends in the utilization of, spending on, and prices for outpatient antifungal agents in US Medicaid programs: 1991-2009

Development of a therapeutic drug-monitoring algorithm for outpatients receiving voriconazole: A multicentre retrospective study

AIMS

Although therapeutic drug monitoring (TDM) of voriconazole is performed in outpatients to prevent treatment failure and toxicity, whether TDM should be performed in all or only selected patients remains controversial. This study evaluated the association between voriconazole trough concentrations and clinical events.

METHODS

We investigated the aggravation of clinical symptoms, incidence of hepatotoxicity and visual disturbances, change in co-medications and interaction between voriconazole and co-medications in outpatients receiving voriconazole between 2017 and 2021 in three facilities. Abnormal trough concentrations were defined as <1.0 mg/L (low group) and >4.0 mg/L (high group).

RESULTS

A total of 141 outpatients (578 concentration measurements) met the inclusion criteria (treatment, 37 patients, 131 values; prophylaxis, 104 patients, 447 values). The percentages of patients with abnormal concentrations were 29.0% and 31.5% in the treatment and prophylaxis groups, respectively. Abnormal concentrations showed 50% of the concentrations at the first measurement in both therapies. Aggravation of clinical symptoms was most frequently observed in the low treatment group (18.2%). Adverse events were most common in the high group for both therapies (treatment, hepatotoxicity 6.3%, visual disturbance 18.8%; prophylaxis, hepatotoxicity 27.9%). No differences were found in changes to co-medications and drug interactions. In the prophylaxis group, prescription duration in the presence of clinical events tended to be longer than in their absence (47.4 ± 23.4 days vs 39.7 ± 21.9 days, P = .1132).

CONCLUSIONS

We developed an algorithm based on clinical events for appropriate implementation of TDM in outpatients. However, future interventions based on this algorithm should be validated.

Trends in utilization, reimbursement, and price for DOACs and warfarin in the US Medicaid population from 2000 to 2020

The use of direct oral anticoagulants (DOACs) is widely increasing in the United States (US). Warfarin has been the conventional anticoagulant used in the past few decades, but it has been gradually replaced by DOACs. The objective of the study was to analyze trends in utilization, reimbursement, and price for those anticoagulants in the US Medicaid population. Retrospective data analysis was conducted using the National Summary Files for the Medicaid State Drug Utilization Data. Study drugs included dabigatran, rivaroxaban, apixaban, edoxaban and warfarin. The study assessed secular trends of utilization, reimbursement, and per-prescription price. The data was collected from the first quarter of 2000 through to the second quarter of 2020 restricted for outpatient prescriptions only. During the 21-year study period, a substantial rise in total expenditures on warfarin and DOACs was observed from $144 million in 2000 to $694 million in 2020. Moreover, the utilization of DOACs has increased significantly since the first approval of Xarelto in 2010 from 1079 in 2011 to 1.5 million in 2019. The per-prescription price of DOACs increased from an average of $200 in 2011 to $407 in 2020. Conversely, the total number of prescriptions of Warfarin and branded Coumadin decreased from 2.4 million to 1.4 million and from 3.9 million to less than a million, respectively. The present study demonstrated a change in the trends of US expenditure and utilization for warfarin and DOACs with DOACs representing the majority of market share of both spending per prescription and reimbursement.

Antifungal drug price increases in the United States, 2000-2019

BACKGROUND

Antifungal drugs treat a variety of conditions, ranging from localised dermatologic disease to life-threatening systemic infections. Some common antifungal drugs experienced large price increases in recent years, however, factors contributing to these price increases are poorly understood. We sought to examine trends in antifungal drug prices and determine underlying drivers of price changes.

METHODS

Antifungal drug products in the United States were identified using the Food and Drug Administration (FDA) Label database. For each product, we determined the wholesale acquisition cost per unit over time between 2000 and 2019, adjusting for inflation, and examined variables that could impact price: route of administration, number of FDA indications, the quantity of professional guideline recommendations, use for prophylaxis, number of FDA-approved manufacturers, and whether it was compounded. Price trajectories were clustered into four groups: (1) stable, 2) moderate, (3) high, and (4) extreme price increases.

RESULTS

Of 139 identified drug products, one outlier was removed due to exorbitant price increases. Cluster 1 (n = 31) demonstrated the most stable prices with a 25% mean price increase. Clusters 2 (n = 97), 3 (n = 7), and 4 (n = 3) demonstrated moderate, high, and extreme price increases with 52%, 318%, and 900% mean price increases, respectively. Atypical routes of administration and compounding were over-represented in clusters 3 and 4. There was no correlation between the number of manufacturers and price changes.

CONCLUSIONS

Antifungal drugs exhibited large, inflation-adjusted price increases. Atypical routes of administration and compounding were over-represented within clusters exhibiting extraordinary price increases. Our data support policies aiming to curb large price increases for medically important drugs.

CAUTION ADVISED USING COMBINATION KETOCONAZOLE AND PD-1 INHIBITORS

Objective

Immune checkpoint inhibitors are approved to treat multiple cancers. We report life-threatening hepatic failure in 2 consecutive patients with Cushing syndrome that were treated with ketoconazole (KTZ) in combination with 2 different programmed cell death protein 1 (PD-1) inhibitors, Nivolumab and Pembrolizumab.

Methods

The first patient suffered from corticotroph pituitary carcinoma and the second from metastatic adrenal cortical carcinoma. They were both treated with KTZ for tumor-associated hypercortisolism.

Results

Hepatic function was normal on KTZ prior to initiation of PD-1 inhibitors, after which they rapidly developed severe hepatic dysfunction. In both cases, liver biopsy was consistent with drug-induced hepatic injury. Liver function fully recovered on discontinuing KTZ and the PD-1 inhibitors along with methylprednisone therapy.

Conclusion

Antifungal azole therapy is commonly used in oncology patients who may be co-treated with PD-1 inhibitors. Although the specific combination of KTZ and PD-1 inhibitors to treat Cushing syndrome may be relatively uncommon, we recommend careful monitoring of hepatic function using a combination PD-1 inhibitors and azole antifungal agents, especially KTZ, due to the potential of life-threatening hepatic failure.

Variability in antifungal stewardship strategies among Society for Healthcare Epidemiology of America (SHEA) Research Network facilities

OBJECTIVE

To characterize antifungal stewardship among antimicrobial stewardship programs (ASPs) at a diverse range of hospitals and to correlate antifungal stewardship with hospital characteristics.

DESIGN

Cross-sectional survey.

PARTICIPANTS

ASP physician and/or pharmacist members at Society for Healthcare Epidemiology of America (SHEA) Research Network (SRN) hospitals.

METHODS

An electronic survey administered August-September 2018 via the SRN to 111 hospitals. The χ2 test was used to test associations between ASP and hospital characteristics and use of antifungal stewardship strategies.

RESULTS

Of 111 hospitals, 45 (41%) responded; most were academic medical centers (65%) caring for stem-cell patients (73.3%) and solid-organ transplant patients (80.0%). Most hospitals have large, well-established ASPs: 60% had >5 team members and 68.9% had a duration ≥6 years. In 43 hospitals (95.6%), ASPs used antifungal stewardship strategies, most commonly prospective audit and feedback (73.3%) by a pharmacist (71.4%). Half of ASPs (51.1%) created guidelines for invasive fungal infection (IFI) management. Most hospitals (71.1%) offered rapid laboratory tests to diagnose IFI, but polymerase chain reaction (PCR) testing and antifungal susceptibility testing varied. Also, 29 ASPs (64.4%) perform surveillance of antifungal utilization, but only 9 (31%) reported to the CDC National Healthcare Safety Network. ASP size, duration, and presence of transplant populations were not associated with a higher likelihood of using antifungal stewardship strategies (P > .05 for all).

CONCLUSIONS

The use of antifungal stewardship strategies was high at SRN hospitals, but they mainly involved audit and feedback. ASPs should be encouraged (1) to disseminate guidelines for IFI management, (2) to promote access to laboratory tests for rapid and accurate IFI diagnosis, and (3) to perform surveillance for antifungal utilization with reporting to the CDC.

Isavuconazole and voriconazole inhibition of sterol 14α-demethylases (CYP51) from Aspergillus fumigatus and Homo sapiens

Here we report the first evaluation of isavuconazole inhibition of Aspergillus fumigatus CYP51 and thus sterol biosynthesis in the fungus. Voriconazole and isavuconazole both bound tightly to recombinant A. fumigatus CYP51 isoenzymes A and B (AfCYP51A and AfCYP51B) isolated in Escherichia coli membranes. CYP51 reconstitution assays confirmed that AfCYP51A and AfCYP51B as well as three AfCYP51A mutants known to confer azole resistance (G54W, L98H and M220K) were strongly inhibited by both triazoles. Voriconazole bound relatively weakly to purified Homo sapiens CYP51 (HsCYP51), unlike isavuconazole that bound tightly. However, isavuconazole was a relatively poor inhibitor of HsCYP51 activity, with an IC₅₀ value (half-maximal inhibitory concentration) of 25 µM, which was 55- to 120-fold greater than those observed for the A. fumigatus CYP51 enzymes, albeit not as poor an inhibitor of HsCYP51 as voriconazole with an IC₅₀ value of 112 µM. Sterol analysis of triazole-treated A. fumigatus Af293 cells confirmed that isavuconazole and voriconazole both inhibited cellular CYP51 activity with the accumulation of 14-methylated sterol substrates and depletion of ergosterol levels. Isavuconazole elicited a stronger perturbation of the sterol composition in A. fumigatus Af293 than voriconazole at 0.0125 µg/mL, indicating increased potency. However, complementation studies in Saccharomyces cerevisiae using strains containing AfCYP51A and AfCYP51B showed isavuconazole to be equally as effective at inhibiting CYP51 activity as voriconazole. These in vitro studies suggest that isavuconazole is an effective alternative to voriconazole as an antifungal agent against the target CYP51 in A. fumigatus.

The Medicaid Rebate: Changes in Oncology Drug Prices After the Affordable Care Act

BACKGROUND

Prescription drug spending is a significant component of Medicaid total expenditures. The Affordable Care Act (ACA) includes a provision that increases the Medicaid rebate for both brand-name and generic drugs. This study examines the extent to which oncology drug prices changed after the increase in the Medicaid rebate in 2010.

METHODS

A pre-post study design was used to evaluate the correlation between the Medicaid rebate increase and oncology drug prices after 2010 using 2006-2013 State Drug Utilization Data.

RESULTS

The results show that the average annual price of top-selling cancer drugs in 2006, adjusted for inflation and secular changes in drug prices, have increased by US$154 and US$235 for branded and competitive brand drugs, respectively, following the 2010 ACA; however, generic oncology drug prices showed no significant changes.

CONCLUSIONS

The findings from this study indicate that oncology drug prices have increased after the 2010 ACA, and suggest that pharmaceutical companies may have increased their drug prices to offset increases in Medicaid rebates.

Utilization, Spending, and Price Trends for Quinolones in the US Medicaid Programs: 25 Years' Experience 1991-2015

BACKGROUND

Given that the quinolones is one of the antibacterial classes most frequently used to treat patients with bacterial infections in the United States, any change in prescribing patterns of quinolones will impact Medicaid medical expenditures.

OBJECTIVES

This study was undertaken to examine trends in utilization, reimbursement, and prices of quinolone antibacterials for the US Medicaid population.

METHODS

The publicly available Medicaid State Drug Utilization outpatient pharmacy files were used for this study. Quarterly and annual prescription counts and reimbursement amounts were calculated for each of the quinolones reimbursed by Medicaid from quarter 1, 1991 through quarter 2, 2015. Average per-prescription reimbursement, as a proxy for drug price, was calculated as the drug reimbursement divided by the number of prescriptions.

RESULTS

The total annual number of quinolone prescriptions increased 402%, from 247,395 in the first quarter of 1991 to 1.2 million in the second quarter of 2015, peaking at 1.3 million in the first quarter of 2005. Similarly, the total reimbursement for quinolone agents increased by 245.5% over the same period. More than 80% of quinolone prescriptions reimbursed by Medicaid were for the second-generation agent, ciprofloxacin, and the third-generation agent, levofloxacin. The average payment per prescription for quinolones increased from US$43.8 in the first quarter of 1991 to US$87.6 in the second quarter of 2015.

CONCLUSIONS

A substantial rise in Medicaid expenditures on quinolones was observed during the 25-year study period, which was mainly because of rising utilization. Therefore, there is a need for additional research that has access to clinically relevant data with which to measure the rate of inappropriate quinolone use among the Medicaid population and associated clinical outcomes and healthcare costs.

Influence of drug class and healthcare setting on systemic antifungal expenditures in the United States, 2005-15

PURPOSE

Overall and specific class trends in systemic antifungal expenditures in various U.S. healthcare settings from 2005 through 2015 were evaluated.

METHODS

Systemic antifungal expenditures from January 1, 2005, through December 31, 2015, were obtained from the QuintilesIMS National Sales Perspective database, which provides a statistically valid projection of medication purchases from multiple markets throughout the United States. Summary data for total antifungal expenditures over the entire period are reported, as are growth and the percentage change in expenditures from one year to the next. Expenditures were also assessed specifically by year, class, and healthcare setting. Expenditure trends over the study period were assessed using simple linear trend regression models.

RESULTS

Overall expenditures for the 11-year period were $9.37 billion. The greatest proportion of expenditures occurred in nonfederal hospitals (47.2%) and for triazoles (57.6%). From 2005 through 2015, total expenditures decreased from $1.1 billion to $894 million (-18.8%, p = 0.09); however, expenditures in clinics and retail pharmacies increased (202%, p < 0.01, and 13.8%, p = 0.04, respectively), a trend most pronounced after 2012. Expenditures for flucytosine also increased (968.1%, p < 0.01), particularly in clinics where there was a dramatic 6,640.9% increase (p < 0.01).

CONCLUSION

From 2005 through 2015, an increase in systemic antifungal expenditures was observed in community settings, despite an overall decrease in total antifungal expenditures in the United States. Large increases in flucytosine expenditures were observed, particularly in the community.

Financial Impact of Direct-Acting Oral Anticoagulants in Medicaid: Budgetary Assessment Based on Number Needed to Treat

BACKGROUND

Faced with rising healthcare costs, state Medicaid programs need short-term, easily calculated budgetary estimates for new drugs, accounting for medical cost offsets due to clinical advantages.

OBJECTIVE

To estimate the budgetary impact of direct-acting oral anticoagulants (DOACs) compared with warfarin, an older, lower-cost vitamin K antagonist, on 12-month Medicaid expenditures for nonvalvular atrial fibrillation (NVAF) using number needed to treat (NNT).

METHOD

Medicaid utilization files, 2009 through second quarter 2015, were used to estimate OAC cost accounting for generic/brand statutory minimum (13/23%) and assumed maximum (13/50%) manufacturer rebates. NNTs were calculated from clinical trial reports to estimate avoided medical events for a hypothetical population of 500,000 enrollees (approximate NVAF prevalence × Medicaid enrollment) under two DOAC market share scenarios: 2015 actual and 50% increase. Medical service costs were based on published sources. Costs were inflation-adjusted (2015 US$).

RESULTS

From 2009-2015, OAC reimbursement per claim increased by 173 and 279% under maximum and minimum rebate scenarios, respectively, while DOAC market share increased from 0 to 21%. Compared with a warfarin-only counterfactual, counts of ischemic strokes, intracranial hemorrhages, and systemic embolisms declined by 36, 280, and 111, respectively; counts of gastrointestinal hemorrhages increased by 794. Avoided events and reduced monitoring, respectively, offset 3-5% and 15-24% of increased drug cost. Net of offsets, DOAC-related cost increases were US$258-US$464 per patient per year (PPPY) in 2015 and US$309-US$579 PPPY after market share increase.

CONCLUSIONS

Avoided medical events offset a small portion of DOAC-related drug cost increase. NNT-based calculations provide a transparent source of budgetary-impact information for new medications.

Piperazine scaffold: A remarkable tool in generation of diverse pharmacological agents

Piperazine is one of the most sought heterocyclics for the development of new drug candidates. This ring can be traced in a number of well established, commercially available drugs. Wide array of pharmacological activities exhibited by piperazine derivatives have made them indispensable anchors for the development of novel therapeutic agents. The review herein highlights the therapeutic significance of piperazine derivatives. Various therapeutically active piperazine derivatives developed by several chemists are reported here.