Isoniazid; pyrazinamide; rifampin - Generic Drug Details
What are the generic drug sources for isoniazid; pyrazinamide; rifampin and what is the scope of patent protection?
Isoniazid; pyrazinamide; rifampin
is the generic ingredient in one branded drug marketed by Sanofi Aventis Us and is included in one NDA. Additional information is available in the individual branded drug profile pages.Summary for isoniazid; pyrazinamide; rifampin
| US Patents: | 0 |
| Tradenames: | 1 |
| Applicants: | 1 |
| NDAs: | 1 |
| Clinical Trials: | 40 |
| DailyMed Link: | isoniazid; pyrazinamide; rifampin at DailyMed |
Recent Clinical Trials for isoniazid; pyrazinamide; rifampin
Identify potential brand extensions & 505(b)(2) entrants
| Sponsor | Phase |
|---|---|
| United States Agency for International Development (USAID) | PHASE3 |
| Johns Hopkins University | PHASE3 |
| E-DA Hospital | PHASE3 |
Anatomical Therapeutic Chemical (ATC) Classes for isoniazid; pyrazinamide; rifampin
US Patents and Regulatory Information for isoniazid; pyrazinamide; rifampin
| Applicant | Tradename | Generic Name | Dosage | NDA | Approval Date | TE | Type | RLD | RS | Patent No. | Patent Expiration | Product | Substance | Delist Req. | Exclusivity Expiration |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sanofi Aventis Us | RIFATER | isoniazid; pyrazinamide; rifampin | TABLET;ORAL | 050705-001 | May 31, 1994 | DISCN | Yes | No | ⤷ Start Trial | ⤷ Start Trial | ⤷ Start Trial | ||||
| >Applicant | >Tradename | >Generic Name | >Dosage | >NDA | >Approval Date | >TE | >Type | >RLD | >RS | >Patent No. | >Patent Expiration | >Product | >Substance | >Delist Req. | >Exclusivity Expiration |
Isoniazid, Pyrazinamide and Rifampin Market Dynamics, Patent Status and Financial Trajectory
Isoniazid, pyrazinamide and rifampin are mature, off-patent tuberculosis medicines with durable clinical demand but limited pricing power. Their commercial value is concentrated in government tenders, Global Fund-supported procurement, public-health programs and fixed-dose combinations. Rifampin has the broadest non-tuberculosis demand and the greatest manufacturing complexity. Isoniazid and pyrazinamide are lower-value commodity products.
The financial outlook is stable in volume and weak in margin. Global tuberculosis incidence supports recurring demand, but generic competition, tender pricing, low reimbursement and procurement concentration constrain revenue growth. No meaningful innovator patent barrier remains for the active ingredients or standard oral products.
What are isoniazid, pyrazinamide and rifampin used for?
The three drugs are core components of drug-susceptible tuberculosis treatment.
| Drug | Primary role | Common adult use | Commercial characteristics |
|---|---|---|---|
| Isoniazid | Bactericidal tuberculosis therapy and latent-TB prevention | Combined with rifampin, pyrazinamide and ethambutol during intensive treatment | Low-cost, widely available generic |
| Pyrazinamide | Sterilizing agent active in acidic environments | Used mainly during the first two months of multidrug therapy | Demand is closely tied to tuberculosis treatment starts |
| Rifampin | Potent bactericidal and sterilizing agent | Used throughout standard drug-susceptible TB therapy | Higher value than isoniazid or pyrazinamide; more interaction and supply risks |
The standard six-month regimen generally consists of two months of isoniazid, rifampin, pyrazinamide and ethambutol, followed by four months of isoniazid and rifampin, subject to clinical and public-health guidance. The U.S. Centers for Disease Control and Prevention and the World Health Organization recommend combination treatment to prevent resistance and improve cure rates (CDC, 2024; WHO, 2024).
Rifampin is also used for selected infections involving staphylococci, including prosthetic-device infections, and for some prophylaxis regimens. Those indications provide incremental demand but do not change the dominant role of tuberculosis procurement.
How large is the market for isoniazid, pyrazinamide and rifampin?
The market is global, recurring and procurement-driven rather than innovation-driven. The World Health Organization estimated that approximately 10.8 million people developed tuberculosis in 2023. Tuberculosis remains concentrated in low- and middle-income countries, where national programs and international donors purchase most first-line medicines (WHO, 2024).
Public procurement determines the majority of market volume. Major buyers include:
- National tuberculosis programs
- The Global Fund to Fight AIDS, Tuberculosis and Malaria
- UN agencies and international procurement organizations
- Government hospitals
- Large nongovernmental and humanitarian health systems
- Retail pharmacies in countries where tuberculosis treatment is less centralized
The Global Fund has reported that tuberculosis programs require several billion dollars annually for prevention, diagnosis and treatment, with financing needs exceeding available resources. First-line drugs represent a small portion of total tuberculosis spending, but they are purchased in large, predictable volumes (Global Fund, 2024).
Market segmentation by product form
The principal products are immediate-release tablets, capsules, oral solutions and fixed-dose combinations.
| Product category | Main buyers | Pricing profile | Market outlook |
|---|---|---|---|
| Isoniazid tablets | Public programs, hospitals, pharmacies | Very low generic pricing | Stable volume, limited margin |
| Pyrazinamide tablets | Public tuberculosis programs | Low generic pricing | Stable but dependent on treatment starts |
| Rifampin capsules or tablets | Public programs and hospitals | Higher price than isoniazid or pyrazinamide | Stable demand with supply-chain sensitivity |
| Isoniazid/rifampin combination | National programs and clinics | Competitive tender pricing | Increasing preference for simplified regimens |
| Rifampin/isoniazid/pyrazinamide combination | National tuberculosis programs | Low unit price, high procurement volume | Strong relevance in public-health tenders |
| Four-drug combinations including ethambutol | National programs and donor-funded procurement | Highly competitive | Important for adherence and logistics |
Fixed-dose combinations reduce pill burden and can simplify procurement. WHO prequalification and national regulatory approval are important commercial requirements for donor-funded supply.
What is the financial trajectory for these drugs?
Revenue growth is expected to track tuberculosis incidence, treatment coverage and procurement budgets rather than price increases. The financial trajectory has four defining characteristics:
- Volume is relatively resilient because tuberculosis treatment cannot be deferred indefinitely.
- Prices remain under pressure because multiple generic suppliers compete in tenders.
- Product shortages can create temporary pricing opportunities but rarely produce durable margin expansion.
- Revenue is concentrated among manufacturers with regulatory approvals, reliable API access and public-procurement eligibility.
Rifampin generally has the strongest revenue profile of the three compounds because it has broader clinical use, higher manufacturing complexity and greater sensitivity to supply interruptions. Isoniazid and pyrazinamide are more commoditized and are often sold as part of bundled or fixed-dose procurement contracts.
Public procurement can produce large shipment volumes while generating modest revenue per patient. A supplier’s financial performance therefore depends on manufacturing utilization, API costs, tender wins, quality compliance and working-capital management. Standard commercial metrics such as branded prescription sales are less useful than awarded contract value, annual tablet volume and supplier concentration.
Revenue exposure by commercial driver
| Driver | Isoniazid | Pyrazinamide | Rifampin |
|---|---|---|---|
| Dependence on tuberculosis programs | Very high | Very high | High |
| Non-TB demand | Limited | Minimal | Meaningful |
| Generic price pressure | Very high | Very high | High |
| Manufacturing complexity | Low to moderate | Moderate | Moderate to high |
| Shortage sensitivity | Moderate | Moderate | High |
| Fixed-dose combination exposure | High | High | High |
| Long-term volume outlook | Stable | Stable | Stable to moderately positive |
There is no reliable, separately reported global revenue figure for the three active ingredients because suppliers generally report them within broader generic, hospital or anti-infective portfolios. Public companies typically do not disclose product-level sales for these mature medicines.
When do isoniazid, pyrazinamide and rifampin lose exclusivity?
The active ingredients lost meaningful composition-of-matter exclusivity decades ago. Isoniazid was introduced in the early 1950s, pyrazinamide became established in tuberculosis treatment during the mid-20th century, and rifampin entered clinical use in the 1960s.
| Asset | Original innovation period | Current exclusivity position |
|---|---|---|
| Isoniazid | Early 1950s | No active composition patent barrier |
| Pyrazinamide | Mid-20th century | No active composition patent barrier |
| Rifampin | 1960s | No active composition patent barrier |
The relevant commercial rights are not basic molecule patents. They are manufacturing know-how, product registrations, supplier qualifications, formulation approvals, quality systems and procurement contracts.
What is the Orange Book status of these tuberculosis drugs?
The FDA Orange Book lists approved drug products and certain patent and exclusivity information. Standard oral products containing isoniazid, pyrazinamide and rifampin are mature generic medicines with no commercially significant innovator exclusivity remaining under the basic active ingredients (FDA, 2024a).
The principal U.S. products include:
- Isoniazid tablets and oral solution
- Pyrazinamide tablets
- Rifampin capsules
- Rifater, containing rifampin, isoniazid and pyrazinamide
- Rifamate, containing rifampin and isoniazid
The branded combination products have long histories and are not protected by a modern, high-value exclusivity platform. Generic competition is therefore governed primarily by abbreviated new drug application approval, manufacturing capacity and supply reliability.
Are there Paragraph IV challenges for isoniazid, pyrazinamide or rifampin?
Paragraph IV litigation risk is low for standard products. Paragraph IV certifications challenge listed patents that an ANDA applicant asserts are invalid, unenforceable or not infringed. The basic oral products have no meaningful active-ingredient patent estate comparable to recently launched specialty medicines.
Potential disputes could still arise around:
- A newly approved dosage form
- A modified-release formulation
- A specific pediatric formulation
- A combination product with a newly patented manufacturing process
- A device or delivery system
- A branded product with later-added formulation claims
Those scenarios are peripheral to the standard market. For ordinary isoniazid, pyrazinamide and rifampin tablets and capsules, the principal entry barriers are regulatory and operational rather than patent-based.
What formulations are protected by patents?
Standard immediate-release tablets and capsules are generally not protected by enforceable, commercially important formulation patents. Fixed-dose combinations may have historical formulation or process patents, but those rights are generally expired or have limited practical effect.
Current differentiation is more likely to come from:
- Pediatric dispersible tablets
- Palatable oral liquids
- Heat- and humidity-stable products
- High-quality fixed-dose combinations
- Packaging designed for public-health distribution
- Products meeting WHO prequalification standards
- Formulations optimized for pediatric dosing or adherence
WHO has promoted dispersible and child-friendly tuberculosis formulations because pediatric treatment has historically been affected by dosing and palatability limitations (WHO, 2023). These products can receive regulatory or procurement advantages without creating durable monopoly pricing.
How strong is the patent estate for these drugs?
The patent estate is weak for the established molecules and standard dosage forms.
| Patent category | Strength | Commercial effect |
|---|---|---|
| Active-ingredient patents | None of practical relevance | No exclusivity |
| Standard tablet and capsule patents | Weak or expired | Generic entry permitted |
| Fixed-dose combination patents | Mostly expired or limited | Low barrier |
| Pediatric and dispersible formulations | Potentially stronger for specific products | May delay direct substitution in narrow markets |
| Manufacturing-process patents | Can protect a particular process | Usually does not prevent alternative production |
| Packaging and device patents | Narrow | Limited market effect |
Manufacturing know-how can still create an effective competitive advantage. Rifampin is particularly sensitive to process consistency, impurity control, stability and API qualification. A patent may be absent while technical barriers remain meaningful.
What FDA regulatory issues affect market supply?
FDA approval does not eliminate commercial risk. Suppliers must maintain current good manufacturing practice compliance, validate API sources and demonstrate product quality. FDA enforcement actions, import alerts, production interruptions and manufacturing-site changes can reduce supply.
Rifampin has greater supply-chain sensitivity than isoniazid or pyrazinamide because:
- It is produced through more complex fermentation and chemical-processing steps.
- It has important drug-drug interactions.
- It may require tighter control of impurities and stability.
- It is used in several combination products.
- A disruption can affect both tuberculosis and non-tuberculosis indications.
The FDA has also identified tuberculosis-drug shortages and supply disruptions in the broader context of essential medicines. Shortages can shift procurement toward alternate suppliers, but they do not necessarily produce sustained industry-wide price expansion (FDA, 2024b).
What generic entry risks exist?
Generic entry risk is already realized rather than prospective. Multiple manufacturers can compete for standard products where local regulatory requirements permit.
The main risks to incumbent suppliers are:
- Tender price erosion
- Loss of WHO prequalification
- Failure to maintain national registrations
- API disruption
- Batch rejection
- Hospital or government contract loss
- Substitution by another fixed-dose combination
- Procurement consolidation
- Reduced tuberculosis incidence in specific markets
The main risks to buyers are different:
- Supplier concentration
- Long lead times
- Quality failures
- Inconsistent product availability
- Dependence on a small number of API producers
- Delayed procurement cycles
Which companies compete in the market?
Competition varies by country and procurement channel. Participants have included large generic manufacturers, regional pharmaceutical companies and public-health suppliers such as Macleods Pharmaceuticals, Lupin, Viatris, Sanofi’s legacy tuberculosis portfolio, Johnson & Johnson’s legacy rifampin-related commercial presence, and manufacturers qualified through WHO or national procurement systems.
The competitive landscape is fragmented at the global level but concentrated within individual tenders. A supplier can have limited global market share and still hold a strong position in a particular national program through registration, historical performance and procurement eligibility.
The most defensible commercial assets are:
- WHO prequalification
- FDA or stringent regulatory authority approval
- Reliable API sourcing
- Broad country registrations
- Proven tender execution
- Pediatric and fixed-dose products
- Low manufacturing cost
- Stable quality history
What patent litigation and settlement agreements affect these drugs?
There is no major current patent-litigation or settlement framework comparable to the litigation surrounding newer branded medicines. Standard isoniazid, pyrazinamide and rifampin products entered the generic market after the relevant foundational patents expired.
Commercial disputes are more likely to involve:
- Contract performance
- Product-quality claims
- Government procurement challenges
- Antitrust issues in supply markets
- Manufacturing-site compliance
- Regulatory enforcement
- Distribution agreements
Licensing deals are generally associated with public-health procurement, technology transfer, local manufacturing or fixed-dose product distribution rather than royalty-bearing molecule licenses.
How do these drugs compare with newer tuberculosis therapies?
Isoniazid, pyrazinamide and rifampin remain first-line products for drug-susceptible tuberculosis. Newer medicines such as bedaquiline, pretomanid and delamanid are more relevant to multidrug-resistant or extensively drug-resistant tuberculosis.
| Factor | Isoniazid/pyrazinamide/rifampin | Newer resistant-TB therapies |
|---|---|---|
| Patent protection | Minimal | More significant, depending on product and jurisdiction |
| Price | Low | Higher |
| Patient population | Large drug-susceptible TB population | Smaller resistant-TB population |
| Procurement model | High-volume tenders | Programmatic and specialized procurement |
| Margin potential | Low | Higher, subject to competition and access programs |
| Clinical role | Established first-line therapy | Selected resistant-TB regimens |
Newer therapies may reduce demand for the older drugs in resistant cases, but they do not displace the standard first-line market for drug-susceptible disease.
Key Takeaways
- Isoniazid, pyrazinamide and rifampin are mature generic tuberculosis medicines with no meaningful composition-patent protection.
- Their market is driven by tuberculosis incidence, treatment coverage, donor financing and government tenders.
- Rifampin has the strongest commercial profile because of broader use, higher manufacturing complexity and greater shortage sensitivity.
- Isoniazid and pyrazinamide are highly commoditized and face severe tender-price pressure.
- Standard products have low Paragraph IV and patent-litigation risk.
- Fixed-dose combinations, pediatric products, WHO prequalification and supply reliability provide the main commercial differentiation.
- Revenue growth is likely to be volume-led and modest, with limited ability to raise prices.
- Manufacturing compliance, API access and procurement eligibility are more important than patent ownership.
FAQs
Is rifampin more valuable commercially than isoniazid?
Yes. Rifampin has broader clinical use and greater manufacturing and supply-chain complexity. It generally has stronger revenue potential than isoniazid, although both remain low-margin generic products.
Are isoniazid and rifampin sold together?
Yes. Isoniazid and rifampin are sold as a fixed-dose combination and are also included with pyrazinamide, with or without ethambutol, in multidrug tuberculosis products.
Does pyrazinamide have a standalone commercial market?
Yes, but its demand is heavily tied to tuberculosis-program purchasing. It has little meaningful non-tuberculosis demand and is frequently procured as part of a combination regimen.
Can a new manufacturer enter the rifampin market without a patent license?
Generally yes for standard rifampin products, because foundational molecule patents have expired. The entrant still needs regulatory approval, compliant manufacturing, qualified API supply and access to relevant procurement channels.
Could tuberculosis incidence create significant upside for these drugs?
Higher incidence can increase unit demand, but public procurement and generic competition usually limit price expansion. The largest financial benefit generally goes to suppliers with excess capacity, reliable delivery and strong tender access.
References
-
Centers for Disease Control and Prevention. (2024). Treatment for drug-susceptible tuberculosis disease. U.S. Department of Health and Human Services.
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Food and Drug Administration. (2024a). Orange Book: Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.
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Food and Drug Administration. (2024b). Drug shortages and supply-chain information. U.S. Department of Health and Human Services.
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Global Fund to Fight AIDS, Tuberculosis and Malaria. (2024). Results report 2024. The Global Fund.
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World Health Organization. (2023). WHO consolidated guidelines on tuberculosis: Module 5, management of tuberculosis in children and adolescents. WHO.
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World Health Organization. (2024). Global tuberculosis report 2024. WHO.
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