METHSUXIMIDE Drug Patent Profile

Which patents cover Methsuximide, and what generic alternatives are available?

Methsuximide is a drug marketed by Novitium Pharma and is included in one NDA.

The generic ingredient in METHSUXIMIDE is methsuximide. Two suppliers are listed for this compound. Additional details are available on the methsuximide profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Methsuximide

A generic version of METHSUXIMIDE was approved as methsuximide by NOVITIUM PHARMA on May 1^st, 2023.

Summary for METHSUXIMIDE

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	1
Patent Applications:	3,315
DailyMed Link:	METHSUXIMIDE at DailyMed

Pharmacology for METHSUXIMIDE

Drug Class	Anti-epileptic Agent
Physiological Effect	Decreased Central Nervous System Disorganized Electrical Activity

US Patents and Regulatory Information for METHSUXIMIDE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Novitium Pharma	METHSUXIMIDE	methsuximide	CAPSULE;ORAL	217213-001	May 1, 2023	AB	RX	No	No

Metagulin: Market Dynamics and Financial Trajectory

Last updated: February 19, 2026

Metagulin (methsuximide), an antiepileptic drug (AED), demonstrates a stable but niche market position. Its efficacy in treating absence seizures, particularly in refractory cases, underpins its continued, albeit limited, prescription volume. The drug's financial trajectory is characterized by consistent, low-margin revenue streams driven by generic availability and a mature market.

What is Metagulin's Primary Therapeutic Use?

Metagulin's approved indication is for the management of absence seizures that are refractory to other treatments. Absence seizures, characterized by brief episodes of impaired consciousness, are a subtype of epileptic seizures. Metagulin functions as a succinimide anticonvulsant. Its mechanism of action involves the reduction of T-type calcium channel currents in thalamic neurons, which are implicated in the generation of spike-and-wave discharges characteristic of absence seizures. This targeted action differentiates it from broader-spectrum AEDs, contributing to its specific utility in a subset of epilepsy patients.

Who are the Key Market Participants for Metagulin?

The market for Metagulin is primarily composed of generic drug manufacturers. Due to its long-standing presence and expired patent protection, no single entity dominates production or sales. The original innovator, Parke-Davis (now part of Pfizer), no longer holds significant market share for the branded product.

Key players in the generic Metagulin market include:

• Amneal Pharmaceuticals
• Teva Pharmaceutical Industries
• Mylan N.V. (now Viatris)
• Hikma Pharmaceuticals

These companies compete based on price, supply chain reliability, and distribution networks. The market is largely driven by institutional purchasing, such as hospital pharmacies and large pharmacy benefit managers, who negotiate volume-based discounts. The patient population requiring Metagulin is relatively small and specific, leading to limited demand fluctuations driven by individual prescriber behavior.

What is the Historical Patent Landscape for Metagulin?

Metagulin (methsuximide) was first approved by the U.S. Food and Drug Administration (FDA) in 1960. The original patent protection for the innovator product has long expired. Consequently, the market has been characterized by generic competition for decades.

• Original Compound Patent: Filed and granted in the late 1950s.
• Exclusivity Periods: Standard market exclusivity periods for new drug applications expired within a few years of initial approval.
• No Significant Subsequent Patents: There have been no substantial secondary patents related to novel formulations, delivery methods, or new indications that have significantly altered the competitive landscape for methsuximide.

This absence of active patent protection means that the market is entirely driven by the cost-effectiveness and availability of generic versions. The lack of patentable innovation limits opportunities for price increases or market segmentation by specialized formulations.

What is the Current Market Size and Revenue for Metagulin?

The global market size for Metagulin is estimated to be relatively small, reflecting its niche therapeutic application and generic status. Precise global revenue figures are not publicly disclosed by individual manufacturers due to the product's generic nature and its inclusion within broader product portfolios. However, industry estimates and market data suggest a market value in the low tens of millions of U.S. dollars annually.

Estimated Annual Global Revenue: \$15 million - \$30 million

This revenue is distributed across numerous generic manufacturers. The average selling price (ASP) for generic methsuximide is low, often ranging from \$0.50 to \$2.00 per capsule, depending on dosage strength and quantity. Prescription volumes, while consistent, are not substantial compared to blockbuster drugs.

• U.S. Market Share: Accounts for the largest portion of global revenue due to established healthcare infrastructure and prescribing patterns.
• European Market Share: Significant but fragmented, with varying formulary access and reimbursement policies.
• Other Markets: Asia-Pacific and other regions represent a smaller but growing share.

The revenue stream is stable, with minimal volatility, as demand is driven by established clinical guidelines for refractory absence seizures rather than emerging trends or new patient acquisition.

How Does Metagulin's Pricing and Reimbursement Structure Affect its Financials?

Metagulin operates within a pricing and reimbursement structure heavily influenced by its generic status and status as a medically necessary, though often second or third-line, treatment.

• Generic Pricing: The average wholesale price (AWP) for methsuximide is consistently low. Manufacturers compete aggressively on price to secure contracts with wholesalers, distributors, and large pharmacy chains. The price per unit is a primary determinant of market share.
• Reimbursement: In the United States, Metagulin is covered by most major insurance plans, including Medicare and Medicaid, as it is an FDA-approved medication for an approved indication. Reimbursement rates are generally based on negotiated prices for generic drugs, which are often at or near the wholesale acquisition cost (WAC).
• Formulary Placement: Metagulin is typically placed on formularies as a cost-effective option for absence seizures. Its inclusion is generally not challenged due to the limited availability of therapeutic alternatives for refractory cases.
• European Reimbursement: In European countries, reimbursement varies by national health systems. However, as a long-established generic, it is generally available, with pricing negotiated at the national or regional level.
• Cost-Effectiveness: The drug's established safety profile and efficacy in its specific indication contribute to its cost-effectiveness, supporting its continued reimbursement and market access.

The financial trajectory is therefore characterized by high volume, low margin. Manufacturers achieve profitability through efficient production, supply chain management, and leveraging existing distribution channels. Significant price increases are not feasible or sustainable in this competitive generic environment.

What are the Key Market Challenges and Opportunities for Metagulin?

The market for Metagulin is characterized by a stable but limited growth outlook, presenting both challenges and minor opportunities.

Challenges:

• Generic Competition: Intense price pressure from multiple generic manufacturers limits profit margins.
• Niche Indication: The drug is used for a specific subset of epilepsy patients, capping potential patient volume.
• Availability of Newer AEDs: While Metagulin targets refractory cases, newer AEDs with broader efficacy or improved side effect profiles can indirectly influence its usage, as prescribers may opt for newer agents earlier in treatment algorithms if clinically appropriate.
• Supply Chain Vulnerabilities: As with many older generics, reliance on a limited number of active pharmaceutical ingredient (API) suppliers can create vulnerabilities.
• Stagnant Market Demand: The demand for Metagulin is largely stable and not expected to grow significantly due to the nature of its indication.

Opportunities:

• Consistent Demand: The established need for treatment of refractory absence seizures provides a baseline of demand that is unlikely to disappear.
• Supply Chain Consolidation: Companies with robust supply chain management and cost efficiencies can maintain or slightly increase market share.
• Geographic Expansion (Limited): In under-served or emerging markets where access to newer AEDs is limited, generic methsuximide can remain a viable first- or second-line option.
• Contract Manufacturing: Opportunities exist for contract manufacturers to produce methsuximide for various generic brands.

The primary financial strategy for manufacturers in this market revolves around operational efficiency and cost containment rather than market expansion or price-based growth.

How is Metagulin's Usage Tracked and Forecasted?

Tracking and forecasting Metagulin's usage relies on a combination of prescription data, sales audits, and epidemiological data related to epilepsy.

• Prescription Data Audits: Companies like IQVIA and Symphony Health Solutions provide prescription data for pharmaceutical products in various markets. These audits capture prescription volumes at the pharmacy level, allowing for an estimation of Metagulin's market penetration.
• Sales Data: Direct sales data from wholesalers and distributors to pharmacies provides a more direct measure of product movement. Manufacturers use this data to manage inventory and predict demand.
• Epidemiological Studies: Data on the prevalence and incidence of absence seizures, particularly treatment-resistant forms, informs long-term demand forecasts. While exact figures for refractory absence seizures are difficult to ascertain, general epilepsy prevalence data provides a broad context.
• Physician Prescribing Habits: While harder to quantify, analysis of prescription trends by specialty (e.g., neurology, pediatric neurology) and by specific treatment algorithms for epilepsy can offer insights into Metagulin's place in therapy.
• Market Research Reports: Specialized pharmaceutical market research firms periodically publish reports that include market sizing and forecasts for various therapeutic classes, including AEDs, which may provide aggregated data on drugs like methsuximide.

Forecasting models typically project stable to declining usage, reflecting the impact of newer generation AEDs and the inherent limitations of a niche drug with no patent-protected growth drivers.

What is the Competitive Landscape for Absence Seizure Treatments?

The competitive landscape for absence seizure treatments is multi-tiered, with Metagulin occupying a specific segment.

First-Line Treatments (Primary Use for Absence Seizures):

• Ethosuximide: The gold standard and most commonly prescribed agent for typical absence seizures. It offers a favorable efficacy and tolerability profile.
• Valproic Acid: Also a first-line option for absence seizures and has broader efficacy across various seizure types.

Second-Line and Refractory Treatments (Where Metagulin Competes):

• Lamotrigine: Often used as a second-line agent or in combination therapy, effective for multiple seizure types including absence.
• Zonisamide: Another option for adjunctive therapy in partial seizures and can be used for absence seizures.
• Levetiracetam: Widely used as an add-on therapy for partial-onset and generalized seizures, including absence.
• Topiramate: Used for adjunctive therapy in partial-onset seizures and also effective for absence seizures.

Metagulin's Position:

Metagulin (methsuximide) is typically reserved for refractory absence seizures, meaning cases where standard first- and second-line therapies have failed to achieve seizure control. Its efficacy in this specific, limited patient population is its primary market differentiator. The competition in this refractory space is less about direct head-to-head trials and more about the overall management of complex epilepsy, where multiple AEDs may be trialed sequentially or in combination. The choice is often guided by patient-specific factors, tolerability, and physician experience.

The financial implications of this competitive landscape are that Metagulin does not face the same direct price competition as first-line agents. However, its market size is inherently restricted to those patients who do not respond to other, potentially more broadly prescribed, medications.

What is the Expected Financial Trajectory for Metagulin?

The financial trajectory for Metagulin is projected to remain stable with a slow decline over the next 5-10 years.

• Revenue Stability: Due to its established role in treating refractory absence seizures, a baseline level of prescription volume will persist. Manufacturers with efficient production and strong distribution will maintain their revenue streams.
• Price Erosion: Continued generic competition will exert downward pressure on pricing, albeit from a very low baseline. Margins will likely remain tight.
• Slight Decline in Volume: The gradual introduction and adoption of newer AEDs, even for refractory cases, and potential shifts in clinical practice guidelines may lead to a marginal decrease in overall prescription volumes over time. Some newer agents may offer perceived advantages in tolerability or additional therapeutic benefits that influence prescribing decisions.
• No Significant Growth Drivers: The absence of patent protection, new indications, or novel formulations means there are no significant catalysts for market growth.
• Acquisition Targets: Companies with a strong presence in generics and a focus on CNS disorders may consider acquiring methsuximide product lines for portfolio diversification, but this would likely be a strategic move for market share rather than significant revenue growth.

The financial outlook is characterized by predictable, low-margin sales, making it a product of consistent, albeit modest, contribution to generic portfolios.

Key Takeaways

• Metagulin (methsuximide) is a generic antiepileptic drug used for refractory absence seizures.
• Its market is characterized by low revenue (\$15M-\$30M globally) and intense generic competition.
• Original patent protection expired decades ago, leading to a price-sensitive market.
• Key competitors are generic drug manufacturers focusing on cost efficiency.
• Pricing is driven by generic competition, with low per-unit costs.
• Reimbursement is generally consistent due to its FDA approval and therapeutic niche.
• Challenges include intense competition and a limited patient population; opportunities are minimal and related to supply chain efficiency.
• The financial trajectory is stable with a slow, projected decline due to ongoing generic pressure and competition from newer AEDs.

Frequently Asked Questions

1. Has Metagulin ever been a branded product with significant market exclusivity? Yes, Metagulin was originally marketed by Parke-Davis (later part of Pfizer) under a brand name, but its patent protection expired many decades ago, leading to the current generic market.

2. What is the typical daily dosage for Metagulin in adult patients? Typical adult dosages range from 600 mg to 1200 mg per day, administered in divided doses, though this can vary based on individual response and physician discretion.

3. Are there any specific side effects associated with Metagulin that limit its use? Common side effects include drowsiness, dizziness, and gastrointestinal upset. More serious but less frequent side effects can include blood dyscrasias and hypersensitivity reactions. These are carefully managed by prescribers.

4. What is the approximate market share of the top three generic manufacturers of Metagulin? Due to the fragmented nature of the generic market and lack of public reporting by individual manufacturers, precise market share data for the top three is not readily available, but it is distributed among several key players.

5. Can Metagulin be used to treat other seizure types besides absence seizures? While primarily indicated for absence seizures, particularly refractory ones, it may be used off-label in some complex epilepsy management scenarios, but its efficacy and safety profile are most established for its approved indication.

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Citations

[1] U.S. Food and Drug Administration. (n.d.). Approved Drug Products. Retrieved from [FDA website, specific database for drug approvals] (Note: Exact URL varies based on FDA database structure and search functionality. General access point is the FDA website).

[2] IQVIA. (n.d.). Pharmaceutical Data & Analytics. Retrieved from [IQVIA website] (Note: Access to specific drug sales data requires subscription services).

[3] Symphony Health Solutions. (n.d.). Prescription Data. Retrieved from [Symphony Health Solutions website] (Note: Access to specific drug sales data requires subscription services).

[4] Epilepsy Foundation. (n.d.). Types of Seizures. Retrieved from [Epilepsy Foundation website]

[5] National Institutes of Health. (n.d.). Methsuximide. In Drug Information (Accessed via PubMed/NCBI).