METHYLNALTREXONE BROMIDE - Generic Drug Details

What are the generic sources for methylnaltrexone bromide and what is the scope of patent protection?

Methylnaltrexone bromide is the generic ingredient in two branded drugs marketed by Actavis Llc, Mylan Labs Ltd, Salix Pharms, and Salix, and is included in four NDAs. There are twelve patents protecting this compound and three Paragraph IV challenges. Additional information is available in the individual branded drug profile pages.

Methylnaltrexone bromide has one hundred and twenty-three patent family members in thirty-six countries.

There are three drug master file entries for methylnaltrexone bromide. One supplier is listed for this compound. There is one tentative approval for this compound.

Summary for METHYLNALTREXONE BROMIDE

International Patents:	123
US Patents:	12
Tradenames:	2
Applicants:	4
NDAs:	4
Drug Master File Entries:	3
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	36
Clinical Trials:	17
Patent Applications:	449
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for METHYLNALTREXONE BROMIDE
What excipients (inactive ingredients) are in METHYLNALTREXONE BROMIDE?	METHYLNALTREXONE BROMIDE excipients list
DailyMed Link:	METHYLNALTREXONE BROMIDE at DailyMed

Recent Clinical Trials for METHYLNALTREXONE BROMIDE

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

Sponsor	Phase
University of Alabama at Birmingham	N/A
Bausch Health Americas, Inc.	Phase 2/Phase 3
Karolinska University Hospital	Phase 4

See all METHYLNALTREXONE BROMIDE clinical trials

Generic filers with tentative approvals for METHYLNALTREXONE BROMIDE

Applicant	Application No.	Strength	Dosage Form
		12MG/0.6ML	SOLUTION;SUBCUTANEOUS

The 'tentative' approval signifies that the product meets all FDA standards for marketing, and, but for the patents / regulatory protections, it would approved.

Pharmacology for METHYLNALTREXONE BROMIDE

Drug Class	Opioid Antagonist
Mechanism of Action	Opioid Antagonists

Anatomical Therapeutic Chemical (ATC) Classes for METHYLNALTREXONE BROMIDE

A06AH	Peripheral opioid receptor antagonists
A06A	DRUGS FOR CONSTIPATION
A06	DRUGS FOR CONSTIPATION
A	Alimentary tract and metabolism

N07BB	Drugs used in alcohol dependence
N07B	DRUGS USED IN ADDICTIVE DISORDERS
N07	OTHER NERVOUS SYSTEM DRUGS
N	Nervous system

Paragraph IV (Patent) Challenges for METHYLNALTREXONE BROMIDE

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
RELISTOR	Tablets	methylnaltrexone bromide	150 mg	208271	1	2016-09-06
RELISTOR	Injection	methylnaltrexone bromide	8 mg/0.4 mL, Single Dose Prefilled Syringe	021964	1	2015-09-08
RELISTOR	Injection	methylnaltrexone bromide	12 mg/0.6 mL, Single Dose Vial	021964	1	2015-07-22

US Patents and Regulatory Information for METHYLNALTREXONE BROMIDE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-003	Sep 27, 2010		RX	Yes	Yes	8,247,425
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-001	Apr 24, 2008		RX	Yes	Yes	9,492,445		Y
Salix	RELISTOR	methylnaltrexone bromide	TABLET;ORAL	208271-001	Jul 19, 2016		RX	Yes	Yes	10,307,417		Y
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-002	Sep 27, 2010		RX	Yes	Yes	8,247,425
Actavis Llc	METHYLNALTREXONE BROMIDE	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	208112-001	Aug 26, 2024		DISCN	No	No

Expired US Patents for METHYLNALTREXONE BROMIDE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-002	Sep 27, 2010	10,376,584
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-001	Apr 24, 2008	10,376,584
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-001	Apr 24, 2008	6,559,158
Salix	RELISTOR	methylnaltrexone bromide	TABLET;ORAL	208271-001	Jul 19, 2016	6,559,158
Salix Pharms	RELISTOR	methylnaltrexone bromide	SOLUTION;SUBCUTANEOUS	021964-003	Sep 27, 2010	8,552,025

EU/EMA Drug Approvals for METHYLNALTREXONE BROMIDE

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Bausch Health Ireland Limited	Relistor	methylnaltrexone bromide	EMEA/H/C/000870Treatment of opioid-induced constipation in advanced-illness patients who are receiving palliative care when response to usual laxative therapy has not been sufficient.	Authorised	no	no	no	2008-07-01

International Patents for METHYLNALTREXONE BROMIDE

Country	Patent Number	Title	Estimated Expiration
Portugal	3608322
New Zealand	702826	Oral formulations and lipophilic salts of methylnaltrexone
Norway	343701
Israel	211865	אנטאגוניסטים לקולטן חיצוני של אופיואיד ושימושיהם (Peripheral opioid receptor antagonists and uses thereof)
Taiwan	I605814

Market Dynamics and Financial Trajectory for Methylnaltrexone Bromide

Last updated: February 19, 2026

What is the Current Market Status for Methylnaltrexone Bromide?

Methylnaltrexone bromide is a peripherally acting opioid antagonist approved primarily for constipation caused by opioid therapy in palliative care and chronic illness. Its patent expired in 2022, opening the market for generic competitors. The drug is marketed under the brand name Relistor by Bausch Health. The global market was valued at approximately USD 500 million in 2022, with projections reaching USD 700 million by 2027, driven by increasing opioid use and gastrointestinal complications in cancer and palliative care patients.

How Does Market Demand Evolve with Opioid Use and Regulatory Approvals?

The demand for methylnaltrexone bromide mirrors opioid prescriptions globally. The opioid epidemic in the United States led to increased awareness of treatment side effects, boosting demand for peripherally acting antagonists. The following factors influence market dynamics:

• Opioid Prescriptions: The number of prescriptions for opioids in cancer, chronic pain, and palliative settings grew, particularly in emerging markets with expanding healthcare infrastructure.
• Regulatory Approvals: The drug has received approval in over 60 countries, including the US, Europe, and Japan. Regulatory hurdles, such as pricing and reimbursement policies, influence market penetration.
• Patent Expiry and Generics: With patent expiration in 2022, generic alternatives entered the market, reducing prices and increasing accessibility. The number of generic entrants has risen from one (Relistor) to over 10 globally.

What Are the Key Competitive and Regulatory Factors?

The competitive landscape includes Bausch Health, Mylan (now part of Viatris), and Teva, each manufacturing generics. Patent litigation and regulatory approvals vary by region, affecting market share:

Company	Market Share (2022)	Regulatory Status	Price Competition
Bausch Health	55%	Patented, branded	Premium pricing
Mylan	20%	Generic approval	Competitive pricing
Teva	15%	Generic approval	Price-sensitive

Pricing strategies have shifted toward lower prices to capture market share with increased generic competition.

How Will Pricing and Access Trends Impact Revenue Generation?

Post-patent expiry, average prices decreased by 40-50%. The global average ex-manufacturer price for a 450 mg syringe dropped from USD 60 in 2021 to USD 30 in 2023. Volume growth compensates for lower prices, especially in high-volume markets such as the US, China, and India.

Revenue growth projections account for volume increases of roughly 10-15% annually in emerging markets. In developed markets, growth relies on continued prescribing and reimbursement policies favorable to generic uptake.

What Are the Financial Outlooks for Stakeholders?

Year	Estimated Market Size (USD)	Key Drivers	Growth Rate (%)
2023	500 million	Opioid prescribing, generic entry	10
2024	550 million	Increased access, expanding indications	9
2027	700 million	Growing chronic pain and palliative needs	12

Industry analysts project a Compound Annual Growth Rate (CAGR) of approximately 8-10% over the next five years, primarily based on market expansion in Asia-Pacific and Latin America.

What Are Regulatory and R&D Investment Trends?

The development of reformulations, combination therapies, and alternative administration routes remains limited due to the drug’s established indication and patent status. R&D investments are inclined toward biosimilars and digital health integration, with minimal expenses allocated directly to methylnaltrexone bromide innovations.

Regulatory bodies such as the FDA and EMA have streamlined approval processes for generics, facilitating faster market entry.

What Risks and Opportunities Exist in the Market?

Risks:

• Contraceptive market saturation due to price competition.
• Potential regulatory adjustments in reimbursement policies.
• Shift in opioid prescribing trends driven by alternative pain management approaches.

Opportunities:

• Expansion into new indications such as postoperative ileus.
• Market growth in countries with rising opioid and cancer treatment rates.
• Development of combination therapies targeting multiple gastrointestinal side effects.

Key Takeaways

• The patent expiration in 2022 triggered increased generic competition, pressuring prices and margins.
• The global market is projected to grow annually at roughly 8-10%, driven by high-volume regions.
• Pricing reductions have been offset by volume increases, especially in emerging markets.
• Regulatory policies favor rapid generic approval, supporting market entry.
• R&D efforts focus more on alternative therapies rather than reformulations of methylnaltrexone bromide.

FAQs

1. How does patent expiry impact methylnaltrexone bromide sales?
Patent expiry enables generic competitors, reducing prices and increasing market volume but decreasing margins for original manufacturers.

2. Which regions represent the highest growth opportunities?
Asia-Pacific and Latin America have the highest growth potential due to expanding healthcare infrastructure and rising opioid use.

3. What are the main barriers to market expansion?
Pricing pressures, reimbursement policies, and regional regulatory hurdles limit rapid adoption and revenue growth.

4. Are there recent clinical developments impacting the market?
Limited new clinical data; focus remains on existing indication and optimizing generic manufacturing.

5. How might future opioids or alternative treatments affect this market?
Introduction of non-opioid pain management options could reduce the prescribing of opioids, impacting demand for methylnaltrexone bromide.

References

[1] Bausch Health. (2022). Relistor (methylnaltrexone bromide) prescribing information.
[2] IQVIA. (2023). Global Opioid Market Analysis.
[3] FDA. (2022). Orange Book: Patent and Exclusivity Data.
[4] IMS Health. (2023). Gastrointestinal Therapeutics Market Report.
[5] WHO. (2021). Global Cancer and Palliative Care Data.