Quinethazone; reserpine - Generic Drug Details

What are the generic drug sources for quinethazone; reserpine and what is the scope of patent protection?

Quinethazone; reserpine is the generic ingredient in one branded drug marketed by Lederle and is included in one NDA. Additional information is available in the individual branded drug profile pages.

Summary for quinethazone; reserpine

US Patents:	0
Tradenames:	1
Applicants:	1
NDAs:	1
DailyMed Link:	quinethazone; reserpine at DailyMed

Anatomical Therapeutic Chemical (ATC) Classes for quinethazone; reserpine

C02AA	Rauwolfia alkaloids
C02A	ANTIADRENERGIC AGENTS, CENTRALLY ACTING
C02	ANTIHYPERTENSIVES
C	Cardiovascular system

C03BA	Sulfonamides, plain
C03B	LOW-CEILING DIURETICS, EXCL. THIAZIDES
C03	DIURETICS
C	Cardiovascular system

US Patents and Regulatory Information for quinethazone; reserpine

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Lederle	HYDROMOX R	quinethazone; reserpine	TABLET;ORAL	013927-001	Approved Prior to Jan 1, 1982		DISCN	No	No

Quinethazone and Reserpine Market Dynamics, Patent Position, and Financial Trajectory

Last updated: September 9, 2026

Quinethazone and reserpine are legacy cardiovascular drugs with no meaningful branded-market growth prospects. Both active ingredients are long off-patent, inexpensive, and exposed to therapeutic substitution. Quinethazone has effectively exited mainstream U.S. prescribing, while reserpine retains limited historical and niche use as an antihypertensive. Public-company filings do not separately report revenue for either drug, indicating immaterial financial exposure at the manufacturer level.

What is the current market status of quinethazone?

Quinethazone is a thiazide-like diuretic formerly marketed in the United States under the Hydromox name. Its commercial role declined as hydrochlorothiazide, chlorthalidone, indapamide and loop diuretics became standard treatment options.

Metric	Quinethazone assessment
Active ingredient	Quinethazone
Drug class	Thiazide-like diuretic
Historical U.S. brand	Hydromox
Primary use	Hypertension and edema
Current branded market	No material branded market
Generic competition	Limited or absent in routine retail distribution
Patent position	Legacy molecule; original composition protection expired
Biosimilar exposure	None
Paragraph IV activity	No commercially significant recent activity identified
Financial outlook	Declining to negligible

Quinethazone’s principal commercial problem is not patent competition. It is clinical displacement. Physicians can select better-known diuretics with broader guideline support, more established dosing protocols and greater pharmacy availability. A product that remains technically approvable but lacks reliable supply and prescription demand has limited economic value.

What formulations are protected by quinethazone patents?

No commercially material active patent estate is associated with quinethazone. The relevant protection was directed primarily to the original drug compound and historical pharmaceutical compositions. Those rights expired many years ago under the patent terms applicable to mid-20th-century drug development.

There is no identifiable current patent barrier covering a differentiated quinethazone extended-release tablet, combination product or delivery system with meaningful market penetration. Any new entrant would face regulatory, manufacturing and distribution challenges rather than exclusivity barriers.

What is the current market status of reserpine?

Reserpine is an alkaloid originally derived from Rauwolfia species and used historically to treat hypertension and psychiatric disorders. It became commercially less important after the adoption of beta blockers, ACE inhibitors, angiotensin receptor blockers, calcium-channel blockers and other modern antihypertensive therapies.

Metric	Reserpine assessment
Active ingredient	Reserpine
Drug class	Antihypertensive; adrenergic neuron-blocking agent
Historical brands	Serpasil and other legacy brands
Current use	Limited, generally historical or niche
Current U.S. branded market	None of material scale
Generic availability	Limited and inconsistent by market
Patent position	Original patents expired
Biosimilar exposure	None
Paragraph IV activity	No material current challenge identified
Financial outlook	Low-volume, low-price market

Reserpine has a larger historical clinical footprint than quinethazone but a weaker modern commercial position. Concerns involving depression, sedation, bradycardia, orthostatic hypotension and gastrointestinal effects reduced its use. The drug remains pharmacologically relevant but is not a growth product in contemporary hypertension portfolios.

How does reserpine compare with quinethazone?

Factor	Quinethazone	Reserpine
Historical therapeutic role	Diuretic	Antihypertensive
Current prescribing	Extremely limited	Limited, with residual niche use
Main substitution risk	Hydrochlorothiazide, chlorthalidone, indapamide	ACE inhibitors, ARBs, calcium-channel blockers, beta blockers
Supply economics	Small-volume legacy product	Small-volume legacy product
Patent value	None of practical significance	None of practical significance
Regulatory value	Low	Low to modest in jurisdictions retaining approval
Commercial upside	Minimal	Minimal
Manufacturing barrier	Active-ingredient sourcing and scale	Active-ingredient sourcing, quality control and scale

Reserpine may have marginally greater residual demand because it remains listed in some formularies and international markets. Neither drug has a credible path to substantial revenue without a new clinical positioning, combination product or geographic market strategy.

When did quinethazone and reserpine lose exclusivity?

Both drugs lost meaningful market exclusivity decades ago. Their original compound patents predate the modern Hatch-Waxman system and have no remaining term. Patent-term restoration, pediatric exclusivity and modern regulatory exclusivity are not relevant to the current products.

Exclusivity category	Quinethazone	Reserpine
Original compound patent	Expired	Expired
Formulation patent	No material active protection identified	No material active protection identified
New chemical entity exclusivity	Not applicable under current framework	Not applicable under current framework
Orphan-drug exclusivity	None identified	None identified
Pediatric exclusivity	None identified	None identified
Reference-product exclusivity	Expired or not commercially relevant	Expired or not commercially relevant

The lack of active exclusivity means a manufacturer could pursue an abbreviated or conventional generic pathway if a reference product and applicable regulatory pathway were available. In practice, low demand reduces the commercial incentive to incur formulation, stability, bioequivalence and manufacturing costs.

What is the FDA and Orange Book status of quinethazone and reserpine?

The Orange Book is relevant only where an approved reference product has active marketing and listed patents or exclusivities. For both drugs, the commercial question is availability rather than patent protection.

The FDA regulatory profile can be summarized as follows:

1. Historical products and labeling exist for both active ingredients.
2. Neither drug has a current innovative-product franchise.
3. No active Orange Book patent listing is known to create a meaningful barrier to generic entry.
4. Regulatory status can differ from commercial availability. An approved label or historical approval does not guarantee an actively marketed product.
5. Neither drug is exposed to biosimilar competition because both are small-molecule medicines.

FDA Drugs@FDA and the Orange Book remain the controlling public sources for approval history, reference-listed-drug status, patent listings and exclusivity data. DailyMed provides current or archived labeling information where a manufacturer continues to publish a label.[1-3]

Are there Paragraph IV challenges for either drug?

No meaningful recent Paragraph IV litigation market is associated with quinethazone or reserpine. Paragraph IV litigation typically arises when a branded reference product has substantial sales and an active patent estate. These drugs lack both characteristics.

A generic applicant could still certify that listed patents are invalid or not infringed if an applicable reference product were listed. That legal mechanism would have limited economic value here because:

• the relevant patents are expired or commercially immaterial;
• sales volumes are low;
• the market has inexpensive therapeutic substitutes;
• a first-filer advantage would not support a large launch opportunity.

What patent litigation affects quinethazone and reserpine?

No material current patent litigation has shaped either product’s market. The absence of litigation reflects the age of the molecules and the lack of commercially valuable patent claims, not a favorable branded position.

Method-of-use patents

Method-of-use patents for legacy antihypertensive and diuretic compounds would face substantial validity, obviousness and written-description challenges if filed around known indications. A new patent could have value only if it covered a genuinely differentiated use supported by new clinical evidence.

For quinethazone, a method-of-use strategy would need to overcome extensive prior art involving thiazide and thiazide-like diuretics. For reserpine, a new use would face prior art covering cardiovascular, autonomic and neuropsychiatric applications.

Manufacturing and formulation patents

Manufacturing know-how may still matter operationally. It does not create durable market exclusivity unless protected by an enforceable patent or held as a trade secret that competitors cannot readily replicate. Potential barriers include:

• qualified active-pharmaceutical-ingredient suppliers;
• impurity and degradation control;
• low-volume batch economics;
• stability testing;
• validated tablet compression and coating processes;
• packaging suitable for long-term storage.

These barriers can produce temporary supply advantages but are unlikely to support premium pricing.

How strong is the patent estate for quinethazone and reserpine?

The patent estates are commercially weak.

Patent-estate factor	Quinethazone	Reserpine
Remaining compound-patent life	None	None
Active composition-of-matter protection	None of material value	None of material value
Active formulation protection	None of material value identified	None of material value identified
Active method-of-use protection	No material protection identified	No material protection identified
Patent litigation leverage	Very low	Very low
Freedom-to-operate risk	Low for the molecule; normal manufacturing risk	Low for the molecule; normal manufacturing risk
Licensing value of patents	Negligible	Negligible

A buyer should distinguish patent freedom to operate from commercial freedom to operate. The molecules are legally old, but a new manufacturer still must manage regulatory compliance, product quality, supply reliability and channel access.

What is the financial trajectory for quinethazone and reserpine?

Neither drug has a separately disclosed revenue stream in major pharmaceutical-company filings. Public financial reporting generally aggregates legacy generic products into broader portfolios, making drug-specific revenue unavailable. The appropriate financial conclusion is therefore directional rather than a precise sales forecast.

Quinethazone financial trajectory

Quinethazone has a structurally declining trajectory:

• prescription demand is low;
• branded pricing power is absent;
• therapeutic substitution is extensive;
• retail distribution is limited;
• manufacturing scale is difficult to justify;
• regulatory maintenance costs can exceed product contribution in small markets.

The most likely economic model is a low-volume product maintained only where a manufacturer can use an existing facility, shared supplier base or established institutional channel.

Reserpine financial trajectory

Reserpine has slightly more residual commercial potential than quinethazone, but the outlook remains limited:

• historical familiarity supports residual demand in selected markets;
• modern antihypertensive therapy constrains growth;
• generic pricing limits gross-margin expansion;
• demand is sensitive to supply continuity;
• regulatory and pharmacovigilance requirements remain disproportionate to revenue at very low volume.

Reserpine could produce modest niche revenue in countries where it remains approved, inexpensive and clinically familiar. It is unlikely to support a meaningful global commercial franchise.

Which companies are challenging or competing with these products?

Neither drug has a conventional branded-versus-generic competitive structure today. Competition comes primarily from therapeutic alternatives.

Quinethazone competitors

The relevant alternatives are:

• hydrochlorothiazide;
• chlorthalidone;
• indapamide;
• furosemide;
• torsemide;
• combination antihypertensive products.

These drugs benefit from broader supply, stronger guideline familiarity or more established use in specific patient populations.

Reserpine competitors

Reserpine competes with:

• ACE inhibitors such as lisinopril;
• ARBs such as losartan;
• calcium-channel blockers such as amlodipine;
• beta blockers such as metoprolol;
• thiazide and thiazide-like diuretics;
• fixed-dose combination antihypertensives.

The competition is clinical and commercial rather than patent-based. Reserpine’s low price does not offset its weaker prescribing position.

What generic launch scenarios exist?

Scenario 1: No new U.S. entrant

This is the most likely scenario. Existing demand is insufficient to justify a new product launch, and prescribers can select widely available alternatives.

Scenario 2: Limited institutional or international launch

A manufacturer with low-cost production and an existing regulatory platform could launch in selected countries or institutional channels. The strategy would depend on low development costs and reliable API supply.

Scenario 3: Reformulated or combination product

A new combination could create some commercial differentiation, but it would require clinical and regulatory support. A combination involving reserpine or quinethazone would face weak prescriber demand unless it addressed a specific underserved population.

Scenario 4: Specialty repositioning

A sponsor could pursue a new indication or pharmacologic niche. This would require new clinical evidence and would carry high development risk relative to the likely market size.

What licensing deals could create value?

No significant recent licensing transactions centered on quinethazone or reserpine are evident in the public pharmaceutical deal market. Any transaction would likely involve:

• a regional marketing right;
• an institutional supply agreement;
• a portfolio transfer of legacy generic products;
• contract manufacturing;
• an international registration package.

Patent licensing would have little value because neither drug has a meaningful active patent estate. The stronger transaction asset would be a regulatory file, established supply chain, market authorization or hospital distribution network.

What geographic markets remain relevant?

The commercial opportunity is likely concentrated in jurisdictions where:

1. the product remains approved;
2. local manufacturers can produce at low cost;
3. physicians retain familiarity with legacy therapies;
4. modern alternatives are less accessible or more expensive;
5. government procurement favors low-cost essential medicines.

The United States offers limited upside because of weak demand, generic substitution and uncertain retail availability. Selected emerging markets may offer residual volume, but pricing and regulatory fragmentation constrain returns. European opportunity is also limited by guideline-driven prescribing and generic competition.

Key Takeaways

• Quinethazone has effectively left the mainstream U.S. pharmaceutical market.
• Reserpine retains limited niche relevance but has no credible high-growth trajectory.
• Both molecules are long off-patent and lack meaningful formulation, method-of-use or manufacturing exclusivity.
• No material current Paragraph IV or patent-litigation threat affects either drug.
• Neither product faces biosimilar risk because both are small molecules.
• Public filings do not disclose drug-specific revenue, and neither product appears financially material to major pharmaceutical companies.
• The main barriers are demand, supply economics, regulatory maintenance and clinical substitution.
• The best commercial opportunity is a low-cost regional or institutional strategy, not a branded U.S. launch.
• Any licensing value would arise from regulatory approvals, distribution rights or manufacturing capacity rather than patents.

FAQs

Is quinethazone still available by prescription?

Quinethazone has no material mainstream U.S. retail presence. Availability depends on jurisdiction, manufacturer supply and pharmacy sourcing.

Is reserpine still used for high blood pressure?

Reserpine is still recognized as an antihypertensive, but modern prescribing is limited because alternative therapies have stronger adoption, broader availability and more favorable tolerability profiles.

Do quinethazone or reserpine have Orange Book patents?

Neither drug has a commercially meaningful active patent position based on the age of the molecules and the absence of a current branded franchise.

Could a company launch a generic reserpine product?

A company could pursue a regulatory pathway where an applicable reference product and market authorization are available. The primary challenge would be insufficient demand and low pricing, not patent infringement.

Which drug has greater commercial potential, quinethazone or reserpine?

Reserpine has greater residual potential because it retains limited niche use in some markets. The difference is small, and neither product offers a compelling growth investment without a low-cost manufacturing or regional distribution advantage.

References

1. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book

2. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/

3. National Library of Medicine. (n.d.). DailyMed: Current medication information. https://dailymed.nlm.nih.gov/dailymed/

4. U.S. Food and Drug Administration. (1984). Drug Price Competition and Patent Term Restoration Act. https://www.fda.gov

5. World Health Organization. (2023). WHO guideline for the pharmacological treatment of hypertension in adults. World Health Organization. https://www.who.int/publications/i/item/9789240081062