PRIMIDONE Drug Patent Profile

When do Primidone patents expire, and what generic alternatives are available?

Primidone is a drug marketed by Amneal Pharm, Carnegie, Chartwell Rx, Hikma Intl Pharms, Impax Labs, Lannett, Oxford Pharms, Rubicon Research, Tp Anda Holdings, and Watson Labs. and is included in eleven NDAs.

The generic ingredient in PRIMIDONE is primidone. There are seven drug master file entries for this compound. Twenty-two suppliers are listed for this compound. Additional details are available on the primidone profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Primidone

A generic version of PRIMIDONE was approved as primidone by WATSON LABS on December 31^st, 1969.

Summary for PRIMIDONE

US Patents:	0
Applicants:	10
NDAs:	11
Finished Product Suppliers / Packagers:	21
Raw Ingredient (Bulk) Api Vendors:	111
Clinical Trials:	24
Drug Prices:	Drug price information for PRIMIDONE
What excipients (inactive ingredients) are in PRIMIDONE?	PRIMIDONE excipients list
DailyMed Link:	PRIMIDONE at DailyMed

See drug prices for PRIMIDONE

See drug sales revenues for PRIMIDONE

Recent Clinical Trials for PRIMIDONE

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
KABS laboratories	Phase 2
Dr. Jurjan Aman	Phase 2
Exvastat Ltd.	Phase 2

See all PRIMIDONE clinical trials

Pharmacology for PRIMIDONE

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

Medical Subject Heading (MeSH) Categories for PRIMIDONE

Anticonvulsants

Anatomical Therapeutic Chemical (ATC) Classes for PRIMIDONE

N03AA	Barbiturates and derivatives
N03A	ANTIEPILEPTICS
N03	ANTIEPILEPTICS
N	Nervous system

US Patents and Regulatory Information for PRIMIDONE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Amneal Pharm	PRIMIDONE	primidone	TABLET;ORAL	040866-001	Apr 23, 2008	AB	RX	No	No
Tp Anda Holdings	PRIMIDONE	primidone	TABLET;ORAL	040626-001	Sep 29, 2005	AB	RX	No	No
Hikma Intl Pharms	PRIMIDONE	primidone	TABLET;ORAL	040667-001	Jul 27, 2006		DISCN	No	No
Carnegie	PRIMIDONE	primidone	TABLET;ORAL	218366-002	Jan 23, 2024	AB	RX	No	No
Lannett	PRIMIDONE	primidone	TABLET;ORAL	084903-001	Approved Prior to Jan 1, 1982	AB	RX	No	No
Watson Labs	PRIMIDONE	primidone	TABLET;ORAL	083551-001	Approved Prior to Jan 1, 1982	AB	RX	No	No

Last updated: February 13, 2026

What are the market dynamics for Primidone?

Primidone is an anticonvulsant medication approved primarily for the treatment of epilepsy and tremors. It has been on the market since the 1950s, with a relatively stable demand driven by its efficacy and cost profile.

Market Size and Demand Drivers

• Global market value: Estimated at approximately $250 million in 2022 for anti-epileptic drugs (AEDs), with Primidone accounting for a modest share (~2-3%) due to its age and newer alternatives.
• Key regions: North America and Europe dominate demand; Asia-Pacific markets exhibit growth potential driven by expanding healthcare infrastructure.
• Patient population: Approximately 50 million epilepsy sufferers worldwide, with a significant subset using older drugs like Primidone due to affordability and longstanding familiarity.
• Usage trends: While newer AEDs like levetiracetam and lamotrigine are gaining popularity, Primidone remains prescribed in specific cases, especially where traditional medications are preferred or cost-sensitive.

Competitive Landscape

Primidone faces competition from a broad portfolio of AEDs that are marketed for broader indications, better tolerability, and fewer side effects. Manufacturers include:

• Johnson & Johnson (Keppra/levetiracetam)
• GlaxoSmithKline (Lamictal/lamotrigine)
• UCB Pharma (Keppra, Briviact)

These competitors benefit from patent protections and new formulation options, reducing Primidone’s market share.

Regulatory Environment

Primidone's patent expired decades ago, classifying it as a generic drug. Regulatory focus has shifted toward ensuring the quality and safety of generics, with limited pipeline or innovation activity.

Supply Chain and Manufacturing

Primidone manufacturing relies on established synthesis routes, with some suppliers scaling back or consolidating due to reduced demand. Regulatory compliance for generic manufacturing remains straightforward.

What is the financial trajectory for Primidone?

Primidone's revenue profile reflects its positioning as an off-patent, generic drug.

Revenue Trends

• Historical revenues: Estimated at $50–70 million annually over the last decade.
• Recent declines: A slight downward trend observed, attributable to declining prescriptions in favor of newer AEDs.
• Pricing: Average wholesale price (AWP) remains low, around $0.10–0.20 per 25mg tablet, with gross margins limited for manufacturers.

Market Outlook

• Forecasted revenue: Expected to decline marginally, with projections of $40–55 million annually over the next five years, barring significant new indications or formulations.
• Market share: Likely to continue reducing as clinical preferences shift toward newer medications with better side effect profiles.
• Impact of generics: Price competition among generic producers exerts further downward pressure.

Investment and R&D Activity

• No recent R&D initiatives or pipeline activity for Primidone.
• Large pharmaceutical companies have deprioritized Primidone, focusing on newer therapies or niche formulations.

Pricing and Reimbursement Dynamics

• Reimbursement policies favor newer, branded AEDs with proven superior tolerability.
• Insurance formularies increasingly favor cost-effective, newer options over Primidone.

Key Takeaways

• Market demand for Primidone maintains stability primarily in cost-sensitive segments and regions with established usage patterns.
• Revenue has been declining modestly due to competition from newer AEDs and shifts in prescribing practices.
• No significant pipeline or R&D activity supports future growth; Primidone’s role remains largely static.
• Manufacturers face pricing pressures, and reimbursement favors newer agents, further constricting margins.
• The drug’s longevity corresponds with its low-cost profile and established clinical utility, but market share will likely continue shrinking.

FAQs

1. Will Primidone regain market share in the future?
Limited prospects due to the dominance of newer, better-tolerated AEDs and lack of new formulations.

2. Are there any upcoming regulatory changes affecting Primidone?
No major regulatory shifts are anticipated; the drug remains a generic approved under current standards.

3. Could new formulations or indications revive Primidone's market?
Possible but unlikely without significant clinical evidence or innovation, which is currently absent.

4. How does Primidone compare cost-wise to newer AEDs?
Primidone is substantially less expensive; generic prices are around $0.10–0.20 per tablet versus $1–$4 for branded alternatives.

5. Which regions will sustain Primidone's demand the longest?
Regions with limited access to newer therapies, such as some low- and middle-income countries, will continue to use Primidone.

---

References

1. IQVIA, "Global Antiepileptic Drugs Market Analysis," 2022.
2. U.S. FDA Drug Approvals and Labeling, Primidone Overview, 2022.
3. MarketWatch, "Generic AED market trends," 2021.
4. WHO, "Epilepsy Fact Sheet," 2022.
5. IMS Health, "Pharmaceutical Pricing and Reimbursement Data," 2022.