US Generic Antiseizure Medication Supply Chain: Observations from Analysis of US Government Databases.

BACKGROUND: Generic drug manufacturing has shifted away from the U.S. in the last few decades. The medication supply chain, from manufacturers to resellers, has become increasingly globalized and complex. This has led to bottlenecks in their manufacture resulting in medication shortages. Review of this process as it pertains to antiseizure medications (ASM) shows gaps in our comprehension of its complexities. Understanding these processes will be essential for preventing medication shortages. OBJECTIVES: The aim of this research is to examine the generic ASM supply with an emphasis on production, labeling, and repackaging. METHODS: Data from the United States Food and Drug Administration (FDA) and the National Library of Medicine (NLM) website DailyMed was used to evaluate supply chain details to gather information on antiseizure medication formulations, manufacturing locations, and labeling. RESULTS: Out of 3142 ASM-related active National Drug Code (NDC-9) codes, 2663 NDC-9 codes with Abbreviated New Drug Application (ANDA) status were included in the analysis. Most (94.8 %) were enteral, with only 5.2 % being parenteral (intravenous and intramuscular route). We identified the manufacturing country for 82 % of these codes, corresponding to 306 unique ANDA numbers. 119 manufacturing sites in 12 countries produce generic ASM Finished Dosage Forms (FDF): 103 for enteral and 21 for parenteral. India is the main producer of enteral ASM FDFs with 49 sites, followed by the US with 36. Regarding parenteral formulation, five countries had 21 unique manufacturing locations. 42 % of the 103 enteral ASM FDFs manufacturing sites produced multiple ASM FDFs, with one facility making eight distinct ASMs. 34.4 % of facilities were associated with over 3 ANDAs, and 15.1 % with more than 5. 22.7 % of ANDAs lacked a manufacturing facility identifier. Repackaged ASM FDFs constituted 48 % of NDC-9 s. Gabapentin and pregabalin were the most common oral ASMs. CONCLUSIONS: India is the major source for generic ASM FDFs manufacturing, leading to concerns about overall supply dependency on that country. There is a paucity of facilities for the global supply of parenteral ASM FDFs. There is missing data for many NDC-9 codes emphasizing urgency for transparency in the supply chain.

Pricing dynamics of anti-seizure medications in the U.S.

BACKGROUND: The median cost of anti-seizure medications (ASM) in the United States (U.S.) nearly doubled per person between 2006 and 2021. This increase, combined with shifts in ASM usage and the impact of the COVID-19 pandemic on drug supply chains amid rising inflation, underscored the urgent need to scrutinize ASM pricing dynamics. This study aimed to analyze the complex dynamics of ASM pricing in the U.S. over the past decade (2013-2023); this included how the entry of generic ASMs influenced the pricing of brand-name counterparts and what impacted price variations across different ASM formulations (e.g., significant inflation, the COVID-19 pandemic). METHODS: This study utilized National Average Drug Acquisition Cost (NADAC) data from November 2013 to July 2023. We adjusted ASM prices for inflation using the Consumer Price Index for Medicinal Drugs - Seasonally Adjusted (CPI-MDS). Statistical analyses included fixed effects regressions and multivariable regression analysis to evaluate the impact of inflation, the number of medication labelers, and the COVID-19 pandemic on ASM prices. RESULTS: Our study analyzed 23 ASMs approved by the U.S. Food and Drug Administration (FDA), which encompassed 223 oral formulations:112 brand-name and 111 generics. From 2013-2016 to 2020-2023, accounting for standard deviations (SD), the average price of brand-name ASMs increased from $8.71 (SD 5.9) to $15.43 (SD 10.7), while generic ASMs saw a slight decrease from $1.39 (SD 1.8) to $1.26 (SD 1.6). Consequently, the price gap between brand-name and generic ASMs surged from 1452.39 % to 3399.26 %. The proportion of matched brand-name and generic ASMs with a price difference of 1000 %-9999 % increased from 32.88 % (2013-2016) to 41.43 % (2020-2023), while those exceeding 10,000 % rose from 16.44 % to 20 % in the same period. Generic immediate-release (IR) formulations were significantly less expensive than extended-release (ER) or delayed-release (DR) counterparts, with cost differences reaching up to 7751.20 %. The number of medication labelers was inversely related to generic ASM prices, which decreased by 5.45 % (p = 0.001) with each additional generic labeler, while brand-name ASM prices increased by 2.46 % (p < 0.001) with each additional generic labeler. The COVID-19 pandemic led to a 24.4 % increase in brand-name ASM prices and a 23.1 % decrease in generic ASM prices. CONCLUSIONS: The findings reveal an expanding price disparity between brand-name and generic oral ASMs. An inverse relationship was observed between the number of medication labelers and generic ASM prices, with additional labelers driving down generic prices. However, introducing more generic labelers led to a significant increase in brand-name ASM prices. Furthermore, following patent expirations, brand-name ASM prices rose-a trend explained by the "generics paradox," where, contrary to expectations, brand prices do not decrease and may even increase when generics enter the market. These findings underscore the need for targeted interventions in drug pricing policies to manage the rising costs associated with epilepsy treatment. To ensure equitable access to ASMs, stakeholders must understand and address the factors driving these pricing dynamics.