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-three 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:	4
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
Mahidol Oxford Tropical Medicine Research Unit	Phase 2/Phase 3
Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit	Phase 2/Phase 3
Brigham and Women's Hospital	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

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	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

International Patents for ZITHROMAX

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

Country	Patent Number	Title	Estimated Expiration
Denmark	172573
Finland	91263
Portugal	87944	PROCESSO PARA A PREPARACAO DE COMPOSTOS 2-AMINO-5-HIDROXI-4-PIRIMIDONAS
Iceland	3370
Slovenia	8811325	PROCESS FOR THE PRODUCTION OF CRYSTALLINE AZITHROMYCIN DIHYDRATE.

Market Dynamics and Financial Trajectory for Zithromax (Azithromycin)

Last updated: October 20, 2025

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Introduction

Zithromax, the brand name for azithromycin, is a widely prescribed macrolide antibiotic developed by Pfizer. Approved by the U.S. Food and Drug Administration (FDA) in 1991, it has become one of the most sold antibiotics globally, primarily addressing respiratory infections, sexually transmitted diseases, and certain bacterial infections. Its unique pharmacokinetics and favorable dosing regimen have cemented its presence in clinical practice, influencing market and financial dynamics significantly.

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Market Overview and Current Landscape

Global Antibiotic Market Context

The anti-infective market has demonstrated resilient growth, driven by increasing antibiotic prescriptions, evolving bacterial resistance, and the expanding global burden of infectious diseases. The global antibiotics market size was valued at approximately $47 billion in 2021 and is projected to grow at a compound annual growth rate (CAGR) of around 3-4% through 2030 [1].

Zithromax's Market Position

Zithromax commands a substantial segment of this market, attributed to its broad-spectrum activity, shorter treatment durations, and safety profile. Historically, it captured around 10-15% of the global antibiotic market share, with peak revenues surpassing $1.8 billion annually during the late 2000s [2].

Key Drivers

• Clinical Advantages: Once-daily dosing, oral bioavailability, and fewer gastrointestinal side effects enhance its adoption.
• Broad Indications: Its efficacy against respiratory, skin, and sexually transmitted infections sustains demand.
• Brand Recognition: Pfizer’s extensive marketing and worldwide distribution infrastructure support its market penetration.

Market Challenges

• Antimicrobial Resistance (AMR): Rising resistance to azithromycin and other macrolides diminishes its effectiveness, leading to reduced prescribing and necessitating new treatment paradigms [3].
• Regulatory Restrictions: In certain regions, strict antimicrobial stewardship policies limit antibiotic prescriptions, influencing sales volumes.
• Generic Competition: Patent expirations and the introduction of generic azithromycin formulations have heightened price competition, affecting profit margins.

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Market Dynamics Influencing Zithromax

1. Pandemic Impact and COVID-19 Effects

Early in the COVID-19 pandemic, azithromycin received attention as part of combination therapies (notably hydroxychloroquine), boosting short-term demand despite limited efficacy evidence [4]. These trends temporarily inflated sales figures but resulted in subsequent adjustments as clinical guidance clarified its limited role in COVID-19 management.

2. Resistance Trends and Prescribing Patterns

The emergence of azithromycin-resistant strains, particularly in Streptococcus pneumoniae and Salmonella species, has led clinicians to limit use for certain indications. Reports indicate resistance rates of 20-30% in some regions, prompting stewardship programs to curb unnecessary prescriptions, which could reduce future revenues [5].

3. Market Expansion in Emerging Economies

Rapid urbanization and increasing access to healthcare in Asia-Pacific, Africa, and Latin America have expanded the potential patient base. As antibiotics are often overprescribed in these markets, the demand for affordable, effective treatments like azithromycin continues to grow, though market penetration is tempered by antimicrobial resistance concerns and regulatory hurdles.

4. Regulatory and Patent Landscape

Pfizer's patent on Zithromax expired in many jurisdictions by the mid-2010s, leading to a surge in generic formulations. While this increased accessibility, it compressed profit margins, pushing Pfizer to focus more on novel formulations or combination therapies for sustained revenue streams.

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Financial Trajectory and Future Outlook

Historical Financial Performance

Pfizer’s Zithromax generated peak revenues exceeding $1.8 billion annually during the late 2000s, cementing it as a blockbuster drug. However, post-patent expiration, revenues declined considerably; generic competition led to substantial price erosion.

Current Revenue Sources

Today, Zithromax's direct sales contribute modestly to Pfizer’s overall revenue, often accounting for less than 1%, with most of its sales derived from generic products licensed through third parties. However, its role in Pfizer’s portfolio remains significant from a strategic perspective—serving as a foundational antibiotic with ongoing research into new indications and formulations.

Strategic Initiatives and Portfolio Diversification

Pfizer is investing in next-generation antimicrobials and adjunctive therapies to offset declining Zithromax revenues. Their focus includes developing diagnostic tools, optimizing dosing regimens, and exploring combination drugs to combat resistance and sustain profitability.

Financial Risks and Opportunities

• Risks: Increasing resistance, regulatory restrictions, and declining market share due to generics.
• Opportunities: Growth in emerging markets, innovative formulations, and repositioning in companion diagnostics or combination therapies could restore some revenue streams.

Forecasting and Market Adjustments

Analysts project a continued decline in Zithromax’s standalone sales over the next five years. Nonetheless, Pfizer’s investment in antimicrobial research and ongoing global health initiatives may pave the way for emerging products inspired by azithromycin’s pharmacological profile, maintaining its strategic significance.

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Implications for Stakeholders

Pharmaceutical Companies

• Focus on combating antimicrobial resistance through reformulation and new drug development.
• Leverage existing brand recognition to develop combination therapies or novel delivery systems.

Healthcare Providers

• Practice antimicrobial stewardship to limit unnecessary azithromycin use, preserving efficacy.
• Adopt rapid diagnostics to ensure targeted therapy, reducing resistance development.

Policy Makers

• Implement stringent regulations on antibiotic prescribing.
• Promote global initiatives to monitor and control antimicrobial resistance.

Investors

• Recognize the declining peak sales of Zithromax but assess Pfizer’s broader antimicrobial innovation pipeline.
• Evaluate emerging opportunities in global markets with rising infectious disease burdens.

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Key Takeaways

• Market saturation and resistance trends have diminished Zithromax’s revenue potential, prompting Pfizer to pivot towards novel antimicrobials and adjunct therapies.
• Global expansion in emerging markets offers a growth avenue, albeit constrained by stewardship policies and resistance.
• Generic competition has significantly lowered prices, challenging profitability but increasing accessibility.
• The pandemic temporarily inflated demand but underscored the importance of antimicrobial stewardship.
• Success in future antimicrobial development hinges on innovative formulations, resistance management, and strategic global partnerships.

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FAQs

1. What are the primary indications for Zithromax?
Zithromax is prescribed for respiratory tract infections (e.g., pneumonia, bronchitis), skin and soft tissue infections, and certain sexually transmitted diseases like chlamydia and gonorrhea.

2. How has antimicrobial resistance affected Zithromax sales?
Rising resistance rates have led to reduced prescribing, especially for respiratory infections, impacting sales volumes and prompting shifts toward alternative treatments.

3. What is the impact of patent expiration on Zithromax’s market?
Patent expiration triggered a wave of generic competition, significantly lowering prices and reducing Pfizer’s direct revenue from Zithromax.

4. Are there ongoing research efforts to develop new uses for azithromycin?
Yes, ongoing research explores azithromycin’s potential anti-inflammatory properties, use in COVID-19, and as a carrier in targeted drug delivery systems, though these are not yet mainstream.

5. What is Pfizer’s strategic approach for antibiotics beyond Zithromax?
Pfizer is investing in next-generation antimicrobial agents, combination therapies, diagnostics, and efforts to combat antibiotic resistance to ensure future growth in the antimicrobial segment.

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References:
[1] Research and Markets, 2022. Global Antibiotics Market Size & Trends.
[2] Pfizer Annual Reports, 2010-2020.
[3] World Health Organization, 2021. Antimicrobial Resistance Global Report.
[4] The New England Journal of Medicine, 2020. Azithromycin and COVID-19: Clinical Efficacy?
[5] Clinical Infectious Diseases, 2022. Resistance Patterns in Azithromycin.

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This comprehensive analysis equips stakeholders with strategic insights into the evolving market, financial prospects, and challenges surrounding Zithromax, guiding informed decision-making in the pharmaceutical landscape.