DYRENIUM Drug Patent Profile

« Back to Dashboard

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

Dyrenium is a drug marketed by Advanz Pharma and is included in one NDA.

The generic ingredient in DYRENIUM is triamterene. There is one drug master file entry for this compound. Five suppliers are listed for this compound. Additional details are available on the triamterene profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Dyrenium

A generic version of DYRENIUM was approved as triamterene by TP ANDA HOLDINGS on August 19^th, 2019.

Summary for DYRENIUM

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	2
Raw Ingredient (Bulk) Api Vendors:	90
Patent Applications:	4,290
Drug Prices:	Drug price information for DYRENIUM
What excipients (inactive ingredients) are in DYRENIUM?	DYRENIUM excipients list
DailyMed Link:	DYRENIUM at DailyMed

See drug prices for DYRENIUM

See drug sales revenues for DYRENIUM

Pharmacology for DYRENIUM

Drug Class	Potassium-sparing Diuretic
Physiological Effect	Decreased Renal K+ Excretion Increased Diuresis

US Patents and Regulatory Information for DYRENIUM

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Advanz Pharma	DYRENIUM	triamterene	CAPSULE;ORAL	013174-001	Approved Prior to Jan 1, 1982	AB	RX	Yes	No
Advanz Pharma	DYRENIUM	triamterene	CAPSULE;ORAL	013174-002	Approved Prior to Jan 1, 1982	AB	RX	Yes	Yes

Dyrenium (Triamterene) Market Dynamics, Patent Status, and Financial Trajectory

Last updated: October 3, 2026

Dyrenium is the brand name for triamterene, an oral potassium-sparing diuretic. Its commercial profile is that of a mature, largely genericized cardiovascular medicine rather than a growth pharmaceutical asset. The U.S. brand has limited commercial visibility, no meaningful data exclusivity, and little evidence of standalone revenue reporting. Market value is concentrated in generic triamterene capsules and fixed-dose combinations such as triamterene/hydrochlorothiazide.

What is Dyrenium and how is it used?

Dyrenium contains triamterene, an epithelial sodium-channel blocker used to reduce potassium loss caused by thiazide or loop diuretics. It is approved for edema associated with congestive heart failure, cirrhosis, and nephrotic syndrome, and for hypertension when potassium conservation is clinically relevant. It is generally used alone or with a thiazide diuretic rather than as a first-line antihypertensive [1].

Dyrenium dosage forms and strengths

Product	Active ingredient	U.S. dosage form	Common strength
Dyrenium	Triamterene	Oral capsule	50 mg, 100 mg
Generic triamterene	Triamterene	Oral capsule	50 mg, 100 mg
Maxzide	Triamterene/hydrochlorothiazide	Oral tablet	37.5/25 mg, 75/50 mg
Dyazide	Triamterene/hydrochlorothiazide	Oral capsule	37.5/25 mg

The core commercial demand is tied to potassium conservation. Triamterene is often selected when a patient receiving hydrochlorothiazide develops hypokalemia or has a clinical reason to avoid potassium supplementation.

What is the FDA regulatory status of Dyrenium?

Dyrenium is an FDA-approved legacy drug with a long-established safety and efficacy record. The product is not a new chemical entity and does not retain meaningful modern regulatory exclusivity.

The relevant regulatory characteristics are:

Regulatory issue	Dyrenium status
Active ingredient	Triamterene
FDA pathway	Original NDA followed by abbreviated new drug applications for generics
New chemical entity exclusivity	Expired
Orphan exclusivity	None identified
Pediatric exclusivity	None identified
Biosimilar relevance	None; triamterene is a small-molecule drug
Primary competition	Generic triamterene and fixed-dose combinations
Commercial classification	Mature, genericized prescription medicine

The original Dyrenium approval predates the modern five-year new chemical entity exclusivity regime. Any commercial protection associated with the original approval has long expired. The FDA-approved labeling warns about hyperkalemia, renal impairment, drug interactions, and the need for serum potassium monitoring [1].

Is Dyrenium currently marketed in the United States?

The brand’s commercial availability has been inconsistent, and generic triamterene is the principal U.S. source of supply. Drug databases have listed Dyrenium as discontinued or unavailable at various points while continuing to list generic triamterene products. A discontinued brand listing does not mean that triamterene therapy has left the market.

The economically relevant product is therefore the active ingredient and its combination products, not the Dyrenium brand name alone.

What patents protect Dyrenium and triamterene?

No material active-patent barrier is associated with the original Dyrenium product. Triamterene was commercialized decades ago, and composition-of-matter, formulation, and regulatory exclusivity periods have expired.

Dyrenium patent position

Protection category	Commercial impact
Composition-of-matter patent	Expired
Original product patent	Expired
Basic capsule formulation protection	Expired or commercially irrelevant
Method-of-use patents	No material barrier identified for established indications
Orange Book-listed patents	No meaningful current barrier expected
Generic substitution	Permitted where state and payer rules allow

The patent position differs from newer diuretics or branded cardiovascular products because triamterene’s active ingredient has been available for many years. Any later patents covering manufacturing processes, specific excipients, or narrow formulations would not normally prevent ordinary generic triamterene competition unless they were listed, enforceable, and commercially relevant.

When did Dyrenium lose exclusivity?

Dyrenium lost meaningful market exclusivity many years ago. Generic triamterene entered the market after the product’s original regulatory and patent protections expired. The exact first generic approval date is less important to present-day valuation than the fact that the product has operated in a multi-source generic market for decades.

Exclusivity timeline

Period	Event	Commercial effect
1960s	Triamterene introduced as a potassium-sparing diuretic	Originator market formation
Pre-1984	Original brand commercialization	Brand-controlled market
1984 onward	Hatch-Waxman abbreviated approval pathway available	Generic entry became possible
Later decades	Generic triamterene and combination products entered	Price competition increased
Current market	Mature multisource supply	Limited brand pricing power

No current regulatory exclusivity period is expected to delay generic competition.

How many patents cover Dyrenium?

The practical answer is zero material blocking patents. The original product does not depend on a live composition-of-matter patent, and any historical patents associated with triamterene or Dyrenium have expired.

The absence of blocking patents creates a low barrier to entry for an ANDA applicant, although market entry still depends on:

• FDA approval of the generic application;
• compliance with capsule manufacturing requirements;
• reliable active pharmaceutical ingredient supply;
• bioequivalence;
• adequate commercial scale;
• reimbursement and wholesaler access.

The principal risks are therefore operational and commercial rather than patent-based.

Are there Paragraph IV challenges to Dyrenium?

Paragraph IV litigation is unlikely to be commercially relevant for Dyrenium because the foundational patents have expired and generic triamterene has long been available. A new Paragraph IV dispute would require a later patent covering a specific formulation, process, or use. Such a dispute would not restore broad exclusivity for triamterene.

Paragraph IV risk assessment

Issue	Assessment
Original Dyrenium patents	Expired
Current Paragraph IV exposure	Low practical relevance
Generic approval pathway	ANDA
Litigation value	Limited unless tied to a narrow later formulation
Launch constraint	Manufacturing, supply, and pricing rather than patent injunction

What formulations are protected by Dyrenium?

The commercial formulations are conventional oral capsules containing 50 mg or 100 mg of triamterene. The formulation itself does not create a durable commercial moat.

Fixed-dose combinations have greater commercial importance than the Dyrenium monotherapy capsule. Triamterene/hydrochlorothiazide products combine potassium conservation with blood-pressure and fluid-volume reduction. Those products compete in a broader prescribing market and may retain stronger pharmacy and payer visibility than the Dyrenium brand.

Formulation competition

Formulation	Market role	Competitive position
Triamterene 50 mg capsule	Lower-dose monotherapy or combination use	Generic, low differentiation
Triamterene 100 mg capsule	Higher-dose therapy	Generic, low differentiation
Triamterene/hydrochlorothiazide capsule	Combination diuretic therapy	Established generic demand
Triamterene/hydrochlorothiazide tablet	Combination therapy	Competes with branded and generic products
Potassium supplements	Alternative for some patients	Lower clinical substitution in selected cases
Amiloride and spironolactone	Alternative potassium-sparing agents	Therapeutic substitutes

What is the market size for Dyrenium and triamterene?

There is no reliable standalone public revenue figure for Dyrenium. Brand-level sales are not generally disclosed in public company filings, and generic triamterene sales are fragmented among multiple manufacturers and wholesalers.

The addressable market is best analyzed through prescription demand rather than brand revenue. Market characteristics include:

1. Stable use in patients requiring potassium conservation.
2. Low unit prices after generic entry.
3. Limited treatment expansion.
4. Substitution by amiloride, spironolactone, potassium supplements, and alternative antihypertensive regimens.
5. Continued use in fixed-dose triamterene/hydrochlorothiazide products.

Triamterene demand is medically durable but commercially narrow. Prescription volume can remain stable while dollar sales decline because generic prices fall and payer substitution increases.

What is the financial trajectory of Dyrenium?

The financial trajectory is structurally mature to declining for the standalone brand. The brand lacks the characteristics that support pharmaceutical revenue expansion: no active exclusivity, limited differentiation, no high-growth indication, and extensive generic substitution.

Revenue trajectory

Financial driver	Effect on Dyrenium
Generic entry	Large reduction in brand pricing power
Brand discontinuation or limited availability	Shifts demand to generic suppliers
Fixed-dose combinations	Preserves active-ingredient demand
Low manufacturing complexity	Supports additional entrants
Payer substitution	Compresses net price
Stable chronic use	Limits volume erosion
Safety monitoring	Restricts use in some renal-impaired patients
Limited innovation	Reduces opportunity for premium repositioning

A reasonable commercial model is:

• Brand Dyrenium revenue: minimal or immaterial relative to major cardiovascular drugs.
• Generic triamterene revenue: recurring but low-margin.
• Combination-product revenue: more resilient than monotherapy revenue.
• Long-term growth: flat to negative in nominal dollars unless supply shortages create temporary price increases.

Revenue could rise temporarily during a shortage or after a competitor exits. Such increases would usually reflect supply disruption rather than durable market expansion.

Which companies compete with Dyrenium?

Competition occurs at three levels: generic triamterene suppliers, fixed-dose combination manufacturers, and therapeutic substitutes.

Generic and combination competitors

The supplier base can change as manufacturers enter or discontinue products. The most relevant competitive groups include:

• Generic capsule manufacturers selling triamterene 50 mg and 100 mg;
• Manufacturers of generic triamterene/hydrochlorothiazide capsules and tablets;
• Contract manufacturers supplying wholesalers and pharmacy chains;
• Branded or authorized-generic suppliers where available.

The competitive landscape is less concentrated around a single originator than it is in newer branded medicines. Distribution, price, manufacturing reliability, and pharmacy contracting determine share.

Therapeutic competitors

Competitor	Role
Amiloride	Alternative epithelial sodium-channel blocker
Spironolactone	Potassium-sparing diuretic with aldosterone-antagonist activity
Eplerenone	More selective aldosterone antagonist
Potassium chloride	Replacement strategy for drug-induced potassium loss
Hydrochlorothiazide alone	Used when potassium conservation is unnecessary
Chlorthalidone or indapamide	Alternative thiazide-like therapy

Spironolactone has a stronger position in heart failure and resistant hypertension, while triamterene is often used for potassium conservation in patients receiving thiazide therapy. The products are not fully interchangeable clinically.

What generic entry risks exist for Dyrenium?

Generic entry risk is already realized rather than prospective. The primary current risk is not a new generic launch but continuing price erosion, supplier consolidation, and intermittent product shortages.

Commercial risks

• Additional generic entrants can reduce average selling prices.
• A manufacturer exit can create temporary shortages and wholesale price volatility.
• Low-margin products may receive less manufacturing investment.
• Active pharmaceutical ingredient disruptions can affect multiple suppliers.
• Hospital and retail buyers may switch suppliers rapidly.
• Brand relaunch economics are weak without a differentiated formulation.

The product’s low price can also create a supply paradox: demand is stable, but manufacturers may have limited incentive to maintain redundant capacity.

What patent litigation affects Dyrenium?

No major current patent litigation is associated with the core Dyrenium product. The product’s legal risk profile is dominated by ordinary pharmaceutical-product issues, including:

• labeling compliance;
• manufacturing quality;
• product recalls;
• supply contracts;
• pharmacy substitution;
• product liability;
• regulatory enforcement.

Patent litigation would have limited value unless a party asserted a narrow later patent covering a specific dosage form or manufacturing process. Such litigation would not materially recreate the original Dyrenium franchise.

Does Dyrenium have biosimilar risk?

Dyrenium has no biosimilar risk because triamterene is a chemically synthesized small-molecule drug. Its competitors use the generic-drug pathway, principally ANDAs, rather than the biologics license application and biosimilar pathways under the Public Health Service Act.

This distinction matters commercially. Generic substitution can occur at lower cost and with less development complexity than biosimilar competition. The absence of biologic manufacturing complexity further lowers the technical entry barrier.

How strong is the Dyrenium patent estate?

The patent estate is weak from an investment perspective. Its value is effectively exhausted because:

• the active ingredient is old;
• the original patents have expired;
• generic products are established;
• no meaningful regulatory exclusivity remains;
• formulation differentiation is limited;
• clinical use is mature.

Patent-strength scorecard

Factor	Assessment
Composition-of-matter protection	None remaining
Formulation protection	Weak or immaterial
Method-of-use protection	Weak
Regulatory exclusivity	None material
Generic entry defense	Very low
Manufacturing complexity	Low to moderate
Brand differentiation	Low
Revenue durability	Moderate volume, weak pricing

How does Dyrenium compare with spironolactone and amiloride?

Factor	Dyrenium/triamterene	Spironolactone	Amiloride
Drug class	Potassium-sparing diuretic	Aldosterone antagonist	Potassium-sparing diuretic
Main commercial use	Potassium conservation with thiazides	Heart failure, resistant hypertension, hyperaldosteronism	Potassium conservation
Generic status	Mature generic	Mature generic	Mature generic
Innovation potential	Low	Higher clinical relevance in selected indications	Low
Patent barrier	None material	No broad blocking barrier	No broad blocking barrier
Key safety issue	Hyperkalemia, renal impairment	Hyperkalemia, endocrine effects	Hyperkalemia
Revenue profile	Low-price, stable niche	Larger clinical market	Smaller niche

Spironolactone has stronger demand because of expanded use in heart failure, resistant hypertension, and endocrine disorders. Triamterene remains relevant where potassium conservation is needed without spironolactone’s hormonal effects.

Key Takeaways

• Dyrenium is the legacy brand for triamterene, a potassium-sparing diuretic.
• The product has no meaningful remaining composition-of-matter, regulatory, or commercial exclusivity.
• Generic triamterene and triamterene/hydrochlorothiazide products define the current market.
• Standalone Dyrenium revenue is not publicly reported and is likely immaterial compared with major cardiovascular products.
• The financial trajectory is mature, low-margin, and generally flat to declining in nominal dollars.
• Fixed-dose combinations provide more durable demand than the standalone brand.
• Paragraph IV and patent-litigation risk are low because the foundational patents expired long ago.
• The main commercial threats are price erosion, manufacturer exits, supply interruptions, and therapeutic substitution.
• Triamterene has no biosimilar exposure because it is a small-molecule drug.
• The asset has recurring clinical demand but weak investment value as a brand or patent-protected franchise.

FAQs About Dyrenium Market and Exclusivity

Is Dyrenium still available by prescription?

Generic triamterene remains the principal source of treatment. Availability of the branded Dyrenium product has been inconsistent, and prescribing commonly shifts to generic capsules or triamterene/hydrochlorothiazide combinations.

Is triamterene a profitable generic drug?

Triamterene can generate recurring revenue but generally has limited margin potential because the product is old, multisource, and price-sensitive. Profitability depends more on manufacturing scale and supply reliability than on brand pricing.

Can a company obtain a new patent on triamterene?

A new patent could potentially cover a genuinely novel formulation, delivery system, manufacturing process, or clinical use. It would not restore broad exclusivity for the existing triamterene capsule without meeting patentability and regulatory requirements.

Is Dyrenium interchangeable with spironolactone?

No. Both conserve potassium, but they have different pharmacology, indications, dosing, adverse-effect profiles, and clinical uses. Substitution requires prescriber judgment.

What is the largest commercial opportunity associated with triamterene?

The most defensible opportunity is reliable generic supply or a differentiated fixed-dose combination. A conventional Dyrenium capsule has limited potential for premium pricing or substantial market expansion.

References

1. U.S. Food and Drug Administration. (n.d.). Dyrenium (triamterene) capsules prescribing information. FDA.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.
3. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs database. FDA.
4. DailyMed. (n.d.). Triamterene capsule drug labeling. National Library of Medicine.
5. U.S. Food and Drug Administration. (1984). Drug Price Competition and Patent Term Restoration Act of 1984. FDA.