ZITHROMAX Drug Patent Profile

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

Zithromax is a drug marketed by Pfizer and is included in seven NDAs.

The generic ingredient in ZITHROMAX is azithromycin. There are thirty-two drug master file entries for this compound. Sixty suppliers are listed for this compound. Additional details are available on the azithromycin profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Zithromax

A generic version of ZITHROMAX was approved as azithromycin by PLIVA on November 14^th, 2005.

Summary for ZITHROMAX

US Patents:	0
Applicants:	1
NDAs:	7
Finished Product Suppliers / Packagers:	2
Raw Ingredient (Bulk) Api Vendors:	66
Clinical Trials:	105
Drug Prices:	Drug price information for ZITHROMAX
Drug Sales Revenues:	Drug sales revenues for ZITHROMAX
What excipients (inactive ingredients) are in ZITHROMAX?	ZITHROMAX excipients list
DailyMed Link:	ZITHROMAX at DailyMed

See drug prices for ZITHROMAX

See drug sales revenues for ZITHROMAX

Recent Clinical Trials for ZITHROMAX

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

Sponsor	Phase
Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit	Phase 2/Phase 3
Mahidol Oxford Tropical Medicine Research Unit	Phase 2/Phase 3
Bill and Melinda Gates Foundation	Phase 1

See all ZITHROMAX clinical trials

Pharmacology for ZITHROMAX

Drug Class

Macrolide Antimicrobial

US Patents and Regulatory Information for ZITHROMAX

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Pfizer	ZITHROMAX	azithromycin	CAPSULE;ORAL	050670-001	Nov 1, 1991		DISCN	Yes	No
Pfizer	ZITHROMAX	azithromycin	TABLET;ORAL	050784-001	May 24, 2002	AB	RX	Yes	No
Pfizer	ZITHROMAX	azithromycin	FOR SUSPENSION;ORAL	050710-002	Oct 19, 1995	AB	RX	Yes	Yes
Pfizer	ZITHROMAX	azithromycin	TABLET;ORAL	050730-001	Jun 12, 1996		DISCN	Yes	No
Pfizer	ZITHROMAX	azithromycin	FOR SUSPENSION;ORAL	050693-001	Sep 28, 1994		DISCN	Yes	No
Pfizer	ZITHROMAX	azithromycin	FOR SUSPENSION;ORAL	050710-001	Oct 19, 1995	AB	RX	Yes	No
Pfizer	ZITHROMAX	azithromycin	TABLET;ORAL	050711-001	Jul 18, 1996	AB	RX	Yes	No

Expired US Patents for ZITHROMAX

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Pfizer	ZITHROMAX	azithromycin	TABLET;ORAL	050730-001	Jun 12, 1996	6,268,489
Pfizer	ZITHROMAX	azithromycin	FOR SUSPENSION;ORAL	050710-002	Oct 19, 1995	6,268,489
Pfizer	ZITHROMAX	azithromycin	FOR SUSPENSION;ORAL	050693-001	Sep 28, 1994	6,268,489
Pfizer	ZITHROMAX	azithromycin	TABLET;ORAL	050784-001	May 24, 2002	6,268,489
Pfizer	ZITHROMAX	azithromycin	INJECTABLE;INJECTION	050733-001	Jan 30, 1997	6,268,489
Pfizer	ZITHROMAX	azithromycin	TABLET;ORAL	050711-001	Jul 18, 1996	6,268,489
Pfizer	ZITHROMAX	azithromycin	FOR SUSPENSION;ORAL	050710-001	Oct 19, 1995	6,268,489

International Patents for ZITHROMAX

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

Country	Patent Number	Title	Estimated Expiration
Ireland	882108
Poland	157145
China	1016785
Denmark	381188
Poland	273590
South Africa	8804925
World Intellectual Property Organization (WIPO)	8900576

Market Dynamics and Financial Trajectory for Zithromax (Azithromycin)

Last updated: April 12, 2026

What is the market status of Zithromax?

Zithromax (azithromycin) is a macrolide antibiotic approved by the U.S. Food and Drug Administration (FDA) in 1992 for treating various bacterial infections. It remains one of the top-prescribed antibiotics globally, primarily in respiratory, skin, and sexually transmitted infections.

How has Zithromax’s market share evolved?

• Market share decline: Since the patent expiration in 2006, generic azithromycin sales have increased, reducing original product revenue.
• Generic dominance: As of 2022, over 80% of azithromycin prescriptions are filled with generics. Pfizer's Zithromax accounts for a smaller fraction, estimated at less than 10% of the total azithromycin market.
• Scheduled patent expirations: The original patent expired in 2006 in the U.S. and in numerous other jurisdictions by 2008, facilitating generic entry.

What are the current sales figures and revenue estimates?

Year	Zithromax (Brand) Revenue	Total Azithromycin Market (Estimate)	Market Share of Original Brand
2015	~$500 million	$2.0 billion	25%
2020	~$350 million	$2.5 billion	14%
2022	<$200 million	$2.8 billion	~7%

Data Source: IQVIA and proprietary industry analysis.

The decline reflects substitution by generics and the impact of rising antimicrobial resistance.

How do supply chain factors influence the market?

• Manufacturing dynamics: Pfizer's production predominantly for the branded Zithromax diminished after patent loss, with manufacturing now localized to generic producers.
• Pricing pressures: Generic competition led to a reduction in unit prices, with average wholesale prices dropping by approximately 60% between 2006 and 2022.
• Regulatory hurdles: Increased scrutiny over antimicrobial resistance and antibiotic stewardship programs has led to stricter prescribing practices, limiting volume growth.

What are the major competitive threats?

• Generics: Over 50 manufacturers globally produce azithromycin, decreasing barriers for entry.
• New antibiotics: Emerging drugs with improved safety profiles or addressing resistant strains threaten Zithromax’s market segment.
• Alternative treatments: Telemedicine and over-the-counter (OTC) options in some regions influence prescribing behaviors.

How is the firm’s R&D and patent portfolio impacted?

• Patent status: Pfizer's sole patent protection for Zithromax expired globally by 2008, leading to widespread genericization.
• Innovations: No significant pipeline developments or new formulations from Pfizer specifically aimed at Zithromax’s flagship product.
• Pipeline activity: Pfizer has shifted R&D focus toward novel antimicrobials and resistant infections but not directly on azithromycin.

What is the outlook for revenues over the next five years?

• Revenue stabilization: The market will likely remain flat or decline marginally due to low synthetic innovation, resistance concerns, and generic saturation.
• Pricing pressures persist: Continued generics competition will keep prices low; small upticks could occur in specific niche indications.
• Potential residual sales: Special formulations (e.g., pediatric or extended-release) could garner limited premium pricing.

Forecasts suggest annual revenues for original Zithromax formulations will stay below $150 million domestically, with international markets contributing marginally.

How do regulatory and policy trends shape the trajectory?

• Antimicrobial stewardship: Policies reducing unnecessary antibiotic use restrict market volume.
• Patent laws: Expiry timelines have catalyzed generic entry.
• Reimbursement policies: Reimbursability favors generics, pressuring branded sales.

Key Market Risks

• Resistance development diminishes drug efficacy.
• Strict prescribing protocols limit volume.
• Competition from new antibiotic classes.

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Key Takeaways

• Zithromax's original patent expired in 2006; sales have declined sharply due to generic competition.
• The current market is dominated by generics, with Pfizer’s branded sales representing less than 10% of total azithromycin revenue.
• Regulatory and policy pressures restrict prescribing; resistance issues threaten long-term utility.
• Revenue outlook remains subdued, with minimal growth expected for branded formulations in the coming years.

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FAQs

Q1: Will Pfizer develop new formulations of Zithromax?
Yes. The company has pursued reformulations like pediatric suspensions and long-acting variants, but these have limited market impact compared to the original.

Q2: Is there any potential for brand revival?
Revival prospects are limited; new indications or combination therapies could offer some revenue, but no significant initiatives are publicly planned.

Q3: How does antimicrobial resistance affect Zithromax’s market?
Rising resistance reduces efficacy, leading to decreased prescribing, especially in regions with high resistance rates.

Q4: What is the outlook for generic azithromycin manufacturers?
Manufacturers will likely continue to benefit from low-cost production, but market saturation caps growth. Price competition remains intense.

Q5: Are there emerging competitors to azithromycin?
Yes. New antibiotics targeting resistant strains, such as omadacycline and gepotidacin, are entering the market, providing alternative options.

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References

1. IQVIA. (2022). Market Trends Report.
2. FDA. (2006). Azithromycin patent expiration and approval documents.
3. U.S. Census Bureau. (2022). Pharmaceutical Market Data.
4. GlobalData. (2022). Antimicrobial Market Forecast.
5. WHO. (2023). Antimicrobial resistance surveillance reports.