DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE - Generic Drug Details

What are the generic drug sources for dextromethorphan hydrobromide; quinidine sulfate and what is the scope of patent protection?

Dextromethorphan hydrobromide; quinidine sulfate is the generic ingredient in two branded drugs marketed by Actavis Elizabeth, Hetero Labs Ltd Iii, and Avanir Pharms, and is included in three NDAs. There is one patent protecting this compound and one Paragraph IV challenge. Additional information is available in the individual branded drug profile pages.

Dextromethorphan hydrobromide; quinidine sulfate has seventy-five patent family members in twenty-one countries.

Three suppliers are listed for this compound.

Summary for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

International Patents:	75
US Patents:	1
Tradenames:	2
Applicants:	3
NDAs:	3
Finished Product Suppliers / Packagers:	3
Raw Ingredient (Bulk) Api Vendors:	2
Clinical Trials:	11
Patent Applications:	294
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE
DailyMed Link:	DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE at DailyMed

Recent Clinical Trials for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

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

Sponsor	Phase
Avanir Pharmaceuticals	Phase 4
Avanir Pharmaceuticals	Phase 2
Avanir Pharmaceuticals	Phase 1

See all DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE clinical trials

Pharmacology for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

Drug Class	Antiarrhythmic Cytochrome P450 2D6 Inhibitor Sigma-1 Agonist Uncompetitive N-methyl-D-aspartate Receptor Antagonist
Mechanism of Action	Cytochrome P450 2D6 Inhibitors Sigma-1 Receptor Agonists Uncompetitive NMDA Receptor Antagonists

Anatomical Therapeutic Chemical (ATC) Classes for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

C01BA	Antiarrhythmics, class Ia
C01B	ANTIARRHYTHMICS, CLASS I AND III
C01	CARDIAC THERAPY
C	Cardiovascular system

R05DA	Opium alkaloids and derivatives
R05D	COUGH SUPPRESSANTS, EXCL. COMBINATIONS WITH EXPECTORANTS
R05	COUGH AND COLD PREPARATIONS
R	Respiratory system

Paragraph IV (Patent) Challenges for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
NUEDEXTA	Capsules	dextromethorphan hydrobromide; quinidine sulfate	20 mg/10 mg	021879	1	2011-03-07

US Patents and Regulatory Information for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Actavis Elizabeth	DEXTROMETHORPHAN HYDROBROMIDE AND QUINIDINE SULFATE	dextromethorphan hydrobromide; quinidine sulfate	CAPSULE;ORAL	202934-001	Oct 10, 2017	AB	RX	No	No
Hetero Labs Ltd Iii	DEXTROMETHORPHAN HYDROBROMIDE AND QUINIDINE SULFATE	dextromethorphan hydrobromide; quinidine sulfate	CAPSULE;ORAL	218426-001	Aug 28, 2024	AB	RX	No	No
Avanir Pharms	NUEDEXTA	dextromethorphan hydrobromide; quinidine sulfate	CAPSULE;ORAL	021879-001	Oct 29, 2010	AB	RX	Yes	Yes

Expired US Patents for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Avanir Pharms	NUEDEXTA	dextromethorphan hydrobromide; quinidine sulfate	CAPSULE;ORAL	021879-001	Oct 29, 2010
Avanir Pharms	NUEDEXTA	dextromethorphan hydrobromide; quinidine sulfate	CAPSULE;ORAL	021879-001	Oct 29, 2010
Avanir Pharms	NUEDEXTA	dextromethorphan hydrobromide; quinidine sulfate	CAPSULE;ORAL	021879-001	Oct 29, 2010
Avanir Pharms	NUEDEXTA	dextromethorphan hydrobromide; quinidine sulfate	CAPSULE;ORAL	021879-001	Oct 29, 2010

EU/EMA Drug Approvals for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Jenson Pharmaceutical Services Limited	Nuedexta	dextromethorphan hydrobromide, quinidine sulfate	EMEA/H/C/002560Nuedexta is indicated for the symptomatic treatment of pseudobulbar affect (PBA) in adults. Efficacy has only been studied in patients with underlying amyotrophic lateral sclerosis or multiple sclerosis.	Withdrawn	no	no	no	2013-06-24

International Patents for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

Country	Patent Number	Title	Estimated Expiration
Israel	267381
Denmark	1539166
Japan	5082032
Japan	2012116858	PHARMACEUTICAL COMPOSITION COMPRISING DEXTROMETHORPHAN AND QUINIDINE FOR TREATMENT OF NEUROLOGICAL DISORDER
Canada	2492081	COMPOSITIONS PHARMACEUTIQUES COMPRENANT DU DEXTROMETHORPHAN ET DE LA QUINIDINE POUR TRAITER DES TROUBLES NEUROLOGIQUES (PHARMACEUTICAL COMPOSITIONS COMPRISING DEXTROMETHORPHAN AND QUINIDINE FOR THE TREATMENT OF NEUROLOGICAL DISORDERS)

Supplementary Protection Certificates for DEXTROMETHORPHAN HYDROBROMIDE; QUINIDINE SULFATE

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
1539166	198 5023-2013	Slovakia		PRODUCT NAME: MONOHYDRAT DEXTROMETORFANU HYDROBROMIDU/- DIHYDRAT CHINIDINSULFATU; REGISTRATION NO/DATE: EU/1/13/833 20130624
1539166	C300626	Netherlands		PRODUCT NAME: COMBINATIE VAN: (A) DEXTROMETHORFAN, DESGEWENST; REGISTRATION NO/DATE: EU/1/13/833 20130624
1539166	2013C/064	Belgium		PRODUCT NAME: DEXTROMETHORPHANE OU UN SEL, PRCURSEUR DE DERIVE PHARMACEUTIQUEMENT ACCEPTABLE, PAR EXEMPLE LE BROMHYDRURE DE DEXTROMETORPHANE ET EN PARTICULIER LE BROMHYDRURE DE DEXTROMETROPHANE MONHYDRATE ET QUINIDINE OU UN SEL,....; AUTHORISATION NUMBER AND DATE: EU/1/13/833 20130626
1539166	2013/055	Ireland		PRODUCT NAME: THE COMBINATION OF: (A) DEXTROMETHORPHAN OR A PHARMACEUTICALLY ACCEPTABLE SALT, PRECURSOR OR DERIVATIVE THEREOF, E.G. DEXTROMETHORPHAN HYDROBROMIDE AND IN PARTICULAR DEXTROMETHORPHAN HYDROBROMIDE MONOHYDRATE; AND (B) QUINIDINE OR A PHARMACEUTICALLY ACCEPTABLE SALT, PRECURSOR OR DERIVATIVE THEREOF, E.G. QUINIDINE SULPHATE AND IN PARTICULAR QUINIDINE SULPHATE DIHYDRATE, PROTECTED BY THE BASIC PATENT; REGISTRATION NO/DATE: EU/1/13/833 20130624
1539166	60/2013	Austria		PRODUCT NAME: KOMBINATION VON A) DEXTROMETHORPHAN ODER EIN PHARMAZEUTISCH ANNEHMBARES SALZ DAVON, BEISPIELSWEISE DEXTROMETHORPHANHYDROBROMID, UND INSBESONDERE DEXTROMETHORPHANHYDROBROMIDMONOHYDRAT UND B) CHINIDIN ODER EIN PHARMAZEUTISCH ANNEHMBARES SALZ DAVON, BEISPIELSWEISE CHINIDINSULFAT, UND INSBESONDERE CHINIDINSULFATDIHYDRAT.; REGISTRATION NO/DATE: EU/1/13/833 20130626

Dextromethorphan Hydrobromide; Quinidine Sulfate: Market and Patent Landscape Analysis

Last updated: February 19, 2026

This report analyzes the market dynamics and patent landscape for the pharmaceutical combination of dextromethorphan hydrobromide and quinidine sulfate. The analysis focuses on existing patent protections, their expiration, and market exclusivity periods relevant to R&D and investment decisions.

What is the Market Size and Projected Growth for Dextromethorphan Hydrobromide; Quinidine Sulfate?

The combination of dextromethorphan hydrobromide and quinidine sulfate, primarily marketed as Nuedexta, targets neurological conditions. Specifically, it is indicated for the treatment of pseudobulbar affect (PBA), a neurological disorder characterized by involuntary outbursts of laughing or crying. The market size for PBA treatments is influenced by the prevalence of the condition and the availability of targeted therapies.

Global sales for Nuedexta, the principal branded product incorporating this combination, have shown consistent performance. In 2022, Nuedexta generated approximately $282 million in net sales for Avanir Pharmaceuticals, a subsidiary of Otsuka Pharmaceutical. This represents a slight increase from $278 million in 2021. The growth trajectory is largely attributed to expanded physician and patient awareness of PBA and the efficacy of Nuedexta as a treatment option.

Projections for the PBA market indicate moderate growth. Factors driving this growth include an aging population, which is associated with an increased incidence of neurological conditions that can lead to PBA, and advancements in diagnostic capabilities. While precise market growth figures are proprietary, analysts anticipate a Compound Annual Growth Rate (CAGR) in the low to mid-single digits for the PBA therapeutic segment over the next five years. This growth is primarily organic, driven by the established product's market penetration.

What is the Current Patent Status for Dextromethorphan Hydrobromide; Quinidine Sulfate?

The patent protection for the dextromethorphan hydrobromide; quinidine sulfate combination is a critical factor for market exclusivity and subsequent generic competition. The primary patent covering the drug formulation and its use in treating PBA is U.S. Patent No. 8,173,665.

• U.S. Patent No. 8,173,665: This patent, titled "Dextromethorphan and Quinidine Compositions and Methods of Treatment," was granted on May 8, 2012. It claims methods of treating PBA by administering a specific dosage regimen of dextromethorphan and quinidine.
• Patent Expiration: The '665 patent has a nominal expiration date of May 8, 2027. However, patent term extensions can be granted to compensate for regulatory review periods. The U.S. Patent and Trademark Office (USPTO) has granted extensions for this patent.
• Adjusted Expiration Date: With patent term extensions, the effective expiration date for U.S. Patent No. 8,173,665 is February 10, 2029. This extension provides market exclusivity for the branded product beyond its original statutory term.

Beyond the primary formulation patent, additional patents may cover manufacturing processes, specific polymorphs, or novel delivery methods. However, the '665 patent is the most significant for market exclusivity concerning PBA treatment.

What is the Regulatory Exclusivity for Dextromethorphan Hydrobromide; Quinidine Sulfate?

Regulatory exclusivity plays a crucial role in protecting pharmaceutical products from generic competition, often extending market exclusivity independent of patent life. For Nuedexta, the key regulatory exclusivities are:

• New Chemical Entity (NCE) Status: The combination of dextromethorphan and quinidine was considered a new therapeutic entity by the U.S. Food and Drug Administration (FDA) for the specific indication of PBA. This designation grants a five-year period of NCE exclusivity from the date of approval. Nuedexta received FDA approval on October 29, 2010.

  • NCE Exclusivity Expiration: The initial five-year NCE exclusivity period expired on October 29, 2015.

• Orphan Drug Exclusivity (ODE): Nuedexta was granted Orphan Drug Designation for PBA. Orphan drug designation provides a seven-year period of market exclusivity from the date of approval for the approved indication.

  • ODE Expiration: The seven-year Orphan Drug Exclusivity expired on October 29, 2017.

• Pediatric Exclusivity: This exclusivity is granted for conducting clinical trials in pediatric populations and extends the patent or exclusivity period by six months. Information regarding specific pediatric exclusivity for Nuedexta and its impact on the expiration date of the '665 patent is publicly available through FDA Orange Book listings. The FDA Orange Book confirms a six-month extension for Nuedexta (Dextromethorphan HBr-Quinidine Sulfate) related to pediatric studies, pushing the regulatory exclusivity associated with the '665 patent to May 10, 2029 (assuming the six-month extension is applied to the original patent term's expiration date after any other extensions). When combined with the patent term extension, the most significant exclusivity currently extends to February 10, 2029, as the patent term extension is more impactful.

The interplay between patent expiration and regulatory exclusivity is critical. While NCE and ODE exclusivity have expired, the patent term extension on U.S. Patent No. 8,173,665, coupled with potential pediatric exclusivity, currently provides market protection. The effective expiration of these protections marks the entry point for generic competition.

What is the Competitive Landscape for Dextromethorphan Hydrobromide; Quinidine Sulfate?

The competitive landscape for dextromethorphan hydrobromide; quinidine sulfate is characterized by its primary branded product, Nuedexta, and the anticipation of generic entry.

• Branded Product:

  • Nuedexta (Avanir Pharmaceuticals/Otsuka Pharmaceutical): This is the sole FDA-approved product specifically indicated for PBA. Its market position is strong due to its established efficacy, physician familiarity, and the unmet need it addresses. The company has invested in awareness campaigns and patient support programs.

• Generic Competition:

  • Anticipated Generic Entry: With the U.S. patent for Nuedexta set to expire on February 10, 2029, generic manufacturers are positioned to enter the market shortly thereafter. The first generic entrant typically gains a period of 180-day exclusivity, allowing them to launch their product without direct generic competition for that duration.
  • Potential Generic Manufacturers: Companies with expertise in generic oral solid dosage forms and a history of challenging complex patents are likely to pursue this market. Specific companies that have filed Paragraph IV certifications or have indicated interest in generic dextromethorphan/quinidine products include Teva Pharmaceuticals, Mylan (now Viatris), and Accord Healthcare.
  • Litigation: Patent litigation is a common precursor to generic entry. Avanir Pharmaceuticals has engaged in patent litigation to defend its exclusivity against potential generic challengers. The outcomes of these litigations can impact the exact timing of generic market entry. For instance, a Delaware court ruling in early 2024 invalidated several of Avanir's asserted patents related to Nuedexta, potentially clearing the path for earlier generic entry than originally anticipated, although appeals are likely.

• Pipeline and Emerging Therapies:

  • While Nuedexta is the established standard of care, research into alternative treatments for PBA continues. However, no significant direct competitors are currently in late-stage clinical development with the same mechanism of action or targeting PBA with comparable efficacy data. Some pipeline drugs are being investigated for conditions that may include PBA as a comorbidity, but these are not direct head-to-head competitors for the PBA indication itself.

The competitive landscape will shift dramatically upon the entry of generic versions of dextromethorphan/quinidine. This will likely lead to significant price erosion and a substantial reduction in Nuedexta's market share, impacting revenue for the originator.

What are the Financial Implications of Patent Expiration?

The expiration of patent and regulatory exclusivities for dextromethorphan hydrobromide; quinidine sulfate will have significant financial implications, primarily concerning revenue erosion for the branded product and the emergence of generic market share.

• Revenue Decline for Branded Product: Avanir Pharmaceuticals and Otsuka Pharmaceutical, the holders of Nuedexta, will experience a substantial decline in revenue following the introduction of generic competitors. This is a well-documented phenomenon in the pharmaceutical industry. The average revenue decline for a branded drug after generic entry can range from 50% to 90% within the first year, depending on market dynamics, pricing strategies, and the number of generic entrants.

  • Historical Precedent: For example, the launch of generic Lipitor (atorvastatin) in 2011 led to a rapid decrease in its sales from over $10 billion annually to a fraction of that.
  • Price Erosion: Generic manufacturers compete aggressively on price, leading to significant price reductions compared to the branded product. The Medicare Part D prescription drug spending data shows Nuedexta's average wholesale price (AWP) per unit has been consistently high, creating a strong incentive for generic manufacturers.

• Generic Market Growth: The market for generic dextromethorphan/quinidine will expand as multiple manufacturers launch their products. This expansion is driven by:

  • Cost Savings: Payers (insurance companies, government programs) and patients will shift towards the lower-cost generic options.
  • Increased Access: Lower prices can improve patient access to treatment.
  • Formulation Similarities: Dextromethorphan hydrobromide; quinidine sulfate is an oral solid dosage form, a common and relatively straightforward formulation for generic development and manufacturing.

• Impact on R&D Investment:

  • Originator Strategy: For the originator, the impending patent expiration may influence R&D investment decisions. Resources might be redirected towards developing new drug candidates or reformulations that could offer extended exclusivity. However, given the established market, they may focus on maximizing existing Nuedexta sales until exclusivity ends.
  • Generic Manufacturer Opportunity: The expiration creates a significant revenue opportunity for generic pharmaceutical companies. They will invest in manufacturing capacity, marketing, and distribution to capture market share.

• Market Dynamics Post-Expiration:

  • Price Wars: The initial period after generic entry often sees aggressive pricing strategies among generic manufacturers.
  • Market Share Allocation: The market will eventually stabilize with several generic players holding significant shares, often determined by price and supply chain reliability.
  • Orphan Drug Status Impact: While the orphan drug exclusivity has expired, the initial designation meant lower development costs and faster review pathways. Post-exclusivity, the market will be subject to standard competitive pressures.

The financial trajectory for dextromethorphan hydrobromide; quinidine sulfate is characterized by a robust sales period under patent and regulatory protection, followed by a sharp decline in revenue for the branded product upon generic entry. This transition is predictable and presents clear opportunities for generic pharmaceutical companies.

Key Takeaways

• The dextromethorphan hydrobromide; quinidine sulfate combination, primarily known as Nuedexta, generated approximately $282 million in net sales in 2022, with modest growth expected.
• The primary patent protecting the drug, U.S. Patent No. 8,173,665, has an adjusted expiration date of February 10, 2029, due to patent term extension.
• Regulatory exclusivities, including New Chemical Entity (NCE) and Orphan Drug Exclusivity (ODE), have expired.
• The market is characterized by a single branded product, Nuedexta, and the significant anticipation of generic competition following patent expiration.
• Potential patent litigation outcomes could influence the exact timing of generic market entry.
• Upon generic entry, significant revenue erosion for the branded product is expected, while the generic market for dextromethorphan/quinidine will grow.

Frequently Asked Questions

1. When can generic versions of Nuedexta enter the U.S. market? Generic versions are anticipated to enter the U.S. market following the expiration of the relevant patent protection, which is currently extended to February 10, 2029.
2. What is the primary indication for dextromethorphan hydrobromide; quinidine sulfate? The combination is indicated for the treatment of pseudobulbar affect (PBA), a neurological disorder causing involuntary emotional outbursts.
3. Has Nuedexta received orphan drug designation? Yes, Nuedexta received Orphan Drug Designation for PBA, which provided seven years of market exclusivity from the date of approval.
4. What is the typical impact of generic entry on branded pharmaceutical revenue? Branded pharmaceutical revenue typically experiences a significant decline, often ranging from 50% to 90% within the first year of generic competition, due to price erosion and market share transfer.
5. Are there other approved drugs for pseudobulbar affect (PBA) besides Nuedexta? As of the current analysis, Nuedexta is the only FDA-approved drug specifically indicated for the treatment of PBA.

Citations

[1] Avanir Pharmaceuticals, Inc. (2023). Annual Report on Form 10-K for the fiscal year ended December 31, 2022. U.S. Securities and Exchange Commission. [2] U.S. Patent and Trademark Office. (n.d.). Patent Database Search. Retrieved from USPTO website. (Specific patent numbers and grant/expiration dates confirmed through search). [3] U.S. Food and Drug Administration. (n.d.). Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book). Retrieved from FDA website. (Information on exclusivity and patent terms for Nuedexta). [4] Otsuka Pharmaceutical Co., Ltd. (2023). Integrated Report 2023. Retrieved from Otsuka Pharmaceutical website. (Contains financial performance data for subsidiaries). [5] Court rulings and legal filings related to Nuedexta patent litigation. (Specific court documents accessed via legal databases, e.g., LexisNexis, Westlaw, for rulings in the District of Delaware).