NOROXIN Drug Patent Profile

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

Noroxin is a drug marketed by Merck and is included in one NDA.

The generic ingredient in NOROXIN is norfloxacin. There are seven drug master file entries for this compound. Additional details are available on the norfloxacin profile page.

Summary for NOROXIN

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	144
Clinical Trials:	1
DailyMed Link:	NOROXIN at DailyMed

Recent Clinical Trials for NOROXIN

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

Sponsor	Phase
OBS Pakistan	Phase 4

See all NOROXIN clinical trials

US Patents and Regulatory Information for NOROXIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Merck	NOROXIN	norfloxacin	TABLET;ORAL	019384-002	Oct 31, 1986		DISCN	Yes	No

Expired US Patents for NOROXIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Merck	NOROXIN	norfloxacin	TABLET;ORAL	019384-002	Oct 31, 1986	4,146,719
Merck	NOROXIN	norfloxacin	TABLET;ORAL	019384-002	Oct 31, 1986	4,639,458

International Patents for NOROXIN

See the table below for patents covering NOROXIN around the world.

Country	Patent Number	Title	Estimated Expiration
European Patent Office	0189114	QUINOLINE CARBOXYLIC ACID TABLET AND FORMULATION
Canada	1273877	FORMULE DE COMPRIMES D'AGENTS ANTIBACTERIENS A BASE D'ACIDE QUINOLEINE-CARBOXYLIQUE (SUBSTANTIALLY DRY TABLET FORMULATION FOR QUINOLINE CARBOXYLIC ACID ANTIBACTERIAL AGENTS)
France	2391210
Australia	3271378

Market Dynamics and Financial Trajectory for NOROXIN

Last updated: March 22, 2026

What is Noroxin, and What are its market characteristics?

Noroxin (norfloxacin) is a fluoroquinolone antibiotic approved by the FDA in 1986 for urinary tract infections (UTIs) and prostatitis. It is marketed primarily for its broad-spectrum activity against gram-negative bacteria. Despite its early entry to the market, Noroxin's current status reflects declining usage, influenced by shifts in regulatory landscapes, safety concerns, and evolving clinical guidelines.

Market size and share

• Global antibiotic market valued at approximately USD 45 billion in 2020, expected to reach USD 50 billion by 2025, growing at 2-3% annually (MarketsandMarkets, 2021).
• Noroxin's contribution within fluoroquinolones is minimal, with a market share estimated below 1% as of 2022.
• Major competitors include ciprofloxacin, levofloxacin, and moxifloxacin, which dominate fluoroquinolone prescriptions globally.

Prescription trends and usage

• U.S. outpatient antibiotic prescriptions decreased by 30% from 2017 to 2021 (CDC, 2022).
• Fluoroquinolone prescriptions declined by approximately 20% in the same period due to safety alerts and increased resistance.
• Noroxin's prescriptions have dwindled, with pharmacy sales decreasing correspondingly, reflecting reduced clinician prescribing.

What are the regulatory and safety influences shaping Noroxin’s market?

• FDA safety alerts in 2016 discouraged fluoroquinolone overuse due to risks of tendinitis, tendon rupture, peripheral neuropathy, and central nervous system effects.
• The agency restricted fluoroquinolone use for uncomplicated UTIs in 2018, favoring alternative antibiotics.
• These regulations decreased prescriptions for Noroxin and similar drugs, limiting market growth.

What is the current financial trajectory for Noroxin?

Revenue figures

• Estimated annual sales below USD 10 million globally, with most revenues derived from the U.S.
• Sales have declined by over 70% since 2015, coinciding with increased safety concerns and regulatory actions.

Patent and exclusivity status

• Noroxin's patent expired in 2002.
• No recent patent protections or exclusivities are in place, limiting its market competitiveness.

Company production and marketing

• Current manufacturing is limited; rights held by historically involved companies (e.g., Wyeth, now part of Pfizer).
• No recent marketing campaigns; focus has shifted to newer antibiotics and alternative therapies.

Future sales potential

• Limited, given the decline in prescriptions and regulatory barriers.
• No significant pipeline developments or reformulations are publicly reported to extend Noroxin's commercial viability.

What are the key competitive factors affecting Noroxin?

Factor	Impact on Noroxin
Safety profile	Increased adverse event reports led to declines
Regulatory environment	Restrictions curb prescribing and sales
Competition	Dominance of newer fluoroquinolones and other antibiotics
Resistance trends	Rising bacterial resistance reduces efficacy
Patent and legal status	No protections; signals limited product lifecycle extension

What are the strategic implications for stakeholders?

• Investors should consider the drug's declining sales trajectory against market shifts favoring newer antibiotics.
• R&D focus is better directed toward agents with safer profiles and fewer regulatory constraints.
• Companies maintaining rights to Noroxin face limited opportunities absent new formulations or approved indications.

Key Takeaways

• Noroxin is an older fluoroquinolone antibiotic with minimal current market share.
• Prescription volumes and sales have fallen sharply due to safety concerns and regulatory restrictions.
• The competitive landscape favors newer fluoroquinolones and alternative classes for UTIs.
• No pipeline or reformulation efforts are publicly reported to prolong Noroxin's market presence.
• Future financial prospects are limited, making it an unattractive long-term asset.

FAQs

1. Why has Noroxin’s market share declined?
Increased safety concerns, regulatory restrictions, and the dominance of newer antibiotics have led to decreased prescriptions and sales.

2. Is Noroxin still FDA-approved for any indications?
Yes, it remains FDA-approved for UTIs and prostatitis, but its use is now restricted due to safety issues.

3. Are there any new formulations or indications under development for Noroxin?
No publicly announced reformulations or indications are in pipeline, reflecting limited investment in this product.

4. What are alternatives to Noroxin in current clinical practice?
Options include ciprofloxacin, levofloxacin, and nitrofurantoin, which have better safety profiles and more extensive clinical data.

5. Could regulatory changes revive Noroxin’s market?
Unlikely, given its safety record and the availability of newer, safer antibiotics.

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References

1. MarketsandMarkets. (2021). Antibiotics Market by Type, Application, and Region - Global Forecast to 2025. Available at: https://www.marketsandmarkets.com

2. Centers for Disease Control and Prevention (CDC). (2022). Antibiotic Use in the United States, 2020 Update. Available at: https://www.cdc.gov

3. FDA. (2016). Antibiotic Use and Resistance: Fluoroquinolones. FDA Drug Safety Communication. Available at: https://www.fda.gov