CLINICAL TRIALS PROFILE FOR QUINAPRIL HYDROCHLORIDE

All Clinical Trials for quinapril hydrochloride

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00065559 ↗	Treatment of Diabetic Nephropathy	Terminated	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	N/A	2003-04-01	COX-2 is an enzyme that is found in several different tissues in the body. COX-2 appears to produce a substance called prostaglandins, mainly at sites of inflammation. Several drugs have been approved by the FDA that inhibit COX-2 such as celecoxib, or brand name Celebrex®. These drugs are primarily used in patients with osteoarthritis and rheumatoid arthritis to decrease inflammation and pain. COX-2 inhibitors have been developed because they are more selective in treatment of inflammation and pain and tend to have fewer gastrointestinal side effects than NSAIDs (nonsteroidal anti-inflammatory drugs) such as aspirin, ibuprofen, naproxen, etc. The normal adult kidney expresses COX-2 in various regions. Prostaglandins, which are produced in the kidney by COX-2, may contribute to glomerular and tubulointerstitial inflammatory diseases (types of kidney diseases due to inflammation). In some animal studies, COX-2 inhibitors have been shown to be potentially beneficial in reducing the amount of protein spilled in the urine and preserving kidney function with these inflammatory kidney diseases. This study will compare the effects of COX-2 inhibitor to placebo (an inactive substance) in patients with diabetic nephropathy (kidney disease due to diabetes) and proteinuria (spilling protein in the urine) on 24-hour urinary protein excretion. This study is designed to see whether COX-2 inhibitors are useful in treating diabetic patients with kidney disease. The purpose of this study is a short-term pilot study that will allow the gathering of important data such as the ability to carry out the study and carry it out safely. Subjects with proteinuria and diabetic kidney disease already on ACE (Angiotensin-Converting Enzyme) inhibitor or ARB (Angiotensin Receptor Blocker) therapy (types of blood pressure medicines) will be randomized to a type of study in which each subject will serve as their own control. The study is set up so that each subject will receive either the COX-2 inhibitor or placebo for a period followed by a period of no drug and then followed by a period of receiving either the COX-2 inhibitor or placebo (whichever they did not receive the first period).
NCT00147524 ↗	Non-Comparative Study To Evaluate Changes In FMD After Quinapril Therapy In Hypertensive Women	Completed	Pfizer	Phase 4	2003-10-01	ACE inhibitors are thought to modify the endothelium in a number of ways. Quinapril is an effective and well-tolerated ACE-I for the treatment of patients with hypertension and congestive heart failure. Quinapril produces favourable haemodynamic changes and improves ventricular and endothelial function in patients with various cardiovascular disorders. These effects are mediated through the binding of quinaprilat to both tissue and plasma-ACE. Quinapril 10 to 40 mg once daily improved endothelial function (as measured by improved FMD or reduced vasoconstrictive/increased vasodilative response to Ach) in patients with CAD and hypertension over 2 to 6 months of therapy; improved endothelial function was also observed in patients with CHF receiving a single infusion of quinaprilat. In general, quinapril showed neutral or beneficial effects on lipid profiles, glycaemia and renal haemodynamics. (3) There are no data available considering effects of quinapril on endothelial dysfunction in post- menopausal woman with mild to moderate hypertension and with pathological endothelial function.
NCT00150826 ↗	QWISE - Study of Quinapril in Women With Chest Pain, Coronary Flow Reserve Limitations and Evidence of Myocardial Ischemia	Completed	National Heart, Lung, and Blood Institute (NHLBI)	Phase 4	2000-05-01	INDICATION Microvascular angina. OBJECTIVES To investigate the effect of ACE (angiotensin converting enzyme) inhibition (quinapril) in improving coronary microvascular function. PATIENT POPULATION Women who meet the National Heart, Lung and Blood Institute-sponsored WISE (Women Ischemia Syndrome Evaluation) study criteria of chest discomfort, coronary flow reserve limitations and evidence for myocardial ischemia in the absence of significant coronary artery stenosis. STUDY DESIGN A prospective, randomized, placebo-controlled, comparative trial. TREATMENT Quinapril 80 mg/d versus placebo for four months. PRIMARY EFFICACY PARAMETER(S) Coronary flow reserve (CFR) at Week 16 adjusted for baseline CFR, treatment group assignment, site-specific variables, and site by treatment effects. SECONDARY EFFICACY PARAMETERS Week 16 change in chest discomfort as measured by the Seattle Angina Questionnaire adjusting for baseline values, site, and site by treatment effects. SAFETY PARAMETERS Hematology, blood chemistries, blood pressure and pulse, and frequency and occurrence of adverse events. STATISTICAL RATIONALE AND ANALYSIS A statistical rationale for the number of patients in the study has been provided. Interim analyses are planned after 15 patients have been enrolled in each group. ANTICIPATED TOTAL NUMBER OF PATIENTS 78 (39 per group). ANTICIPATED NUMBER OF PATIENTS AT EACH SITE Approximately 26
NCT00150826 ↗	QWISE - Study of Quinapril in Women With Chest Pain, Coronary Flow Reserve Limitations and Evidence of Myocardial Ischemia	Completed	University of Florida	Phase 4	2000-05-01	INDICATION Microvascular angina. OBJECTIVES To investigate the effect of ACE (angiotensin converting enzyme) inhibition (quinapril) in improving coronary microvascular function. PATIENT POPULATION Women who meet the National Heart, Lung and Blood Institute-sponsored WISE (Women Ischemia Syndrome Evaluation) study criteria of chest discomfort, coronary flow reserve limitations and evidence for myocardial ischemia in the absence of significant coronary artery stenosis. STUDY DESIGN A prospective, randomized, placebo-controlled, comparative trial. TREATMENT Quinapril 80 mg/d versus placebo for four months. PRIMARY EFFICACY PARAMETER(S) Coronary flow reserve (CFR) at Week 16 adjusted for baseline CFR, treatment group assignment, site-specific variables, and site by treatment effects. SECONDARY EFFICACY PARAMETERS Week 16 change in chest discomfort as measured by the Seattle Angina Questionnaire adjusting for baseline values, site, and site by treatment effects. SAFETY PARAMETERS Hematology, blood chemistries, blood pressure and pulse, and frequency and occurrence of adverse events. STATISTICAL RATIONALE AND ANALYSIS A statistical rationale for the number of patients in the study has been provided. Interim analyses are planned after 15 patients have been enrolled in each group. ANTICIPATED TOTAL NUMBER OF PATIENTS 78 (39 per group). ANTICIPATED NUMBER OF PATIENTS AT EACH SITE Approximately 26
NCT00154050 ↗	High Dose Candesartan Versus Quinapril for Restenosis Prophylaxis After Stent Angioplasty	Completed	Technische Universität Dresden	N/A	2004-05-01	The study is designed to test the hypothesis that high dose candesartan treatment compared to quinapril is able to reduce intima hyperproliferation and the restenosis rate after stent angioplasty in peripheral occlusive artery disease.
NCT00159692 ↗	Amlodipine Diabetic Hypertension Efficacy Response Trial	Completed	Pfizer	Phase 4	2003-03-01	To evaluate the percentage of subjects that reach the diabetic hypertensive blood pressure goal of

Clinical Trial Conditions for quinapril hydrochloride

Condition Name

Condition Name for quinapril hydrochloride
Intervention	Trials
Hypertension	10
Healthy	6
Essential Hypertension	1
Arterial Occlusive Diseases	1

Condition MeSH

Condition MeSH for quinapril hydrochloride
Intervention	Trials
Hypertension	10
Diabetes Mellitus	4
Diabetic Neuropathies	2
Kidney Diseases	2

Clinical Trial Locations for quinapril hydrochloride

Trials by Country

Trials by Country for quinapril hydrochloride
Location	Trials
United States	12
India	11
Spain	4
Canada	3
Hungary	2

Trials by US State

Trials by US State for quinapril hydrochloride
Location	Trials
North Dakota	4
Tennessee	2
Nebraska	1
Georgia	1
Texas	1

Clinical Trial Progress for quinapril hydrochloride

Clinical Trial Phase

Clinical Trial Phase for quinapril hydrochloride
Clinical Trial Phase	Trials
Phase 4	16
Phase 3	1
Phase 1	4

Clinical Trial Status

Clinical Trial Status for quinapril hydrochloride
Clinical Trial Phase	Trials
Completed	24
Terminated	2
Unknown status	1

Clinical Trial Sponsors for quinapril hydrochloride

Sponsor Name

Sponsor Name for quinapril hydrochloride
Sponsor	Trials
Pfizer	7
Mylan Pharmaceuticals	4
Montreal Heart Institute	2

Sponsor Type

Sponsor Type for quinapril hydrochloride
Sponsor	Trials
Other	23
Industry	18
NIH	4

Quinapril Hydrochloride: Clinical Trials, Market Landscape, and Future Projections

Last updated: February 19, 2026

Quinapril hydrochloride is an angiotensin-converting enzyme (ACE) inhibitor used primarily for treating hypertension and heart failure. Its market performance is driven by established efficacy, patent expiries, and the emergence of generic competition.

What are the Current Clinical Trial Trends for Quinapril Hydrochloride?

Current clinical trial activity for quinapril hydrochloride is limited, reflecting its status as an older, off-patent medication. Research focuses on comparative effectiveness studies, post-market surveillance, and exploration of its use in specific patient subpopulations or as an add-on therapy.

• Comparative Effectiveness Studies: Trials often compare quinapril hydrochloride to newer antihypertensive agents, including other ACE inhibitors, angiotensin II receptor blockers (ARBs), and calcium channel blockers. These studies aim to define its relative efficacy and safety profile in diverse patient groups, such as those with resistant hypertension or specific comorbidities. For instance, a study published in the Journal of Human Hypertension in 2022 analyzed the efficacy of quinapril in combination with hydrochlorothiazide versus losartan for blood pressure control in a real-world setting. The trial reported similar efficacy between the two regimens in achieving target blood pressure, but noted a higher incidence of cough in the quinapril group [1].
• Post-Market Surveillance and Real-World Evidence: Ongoing observational studies and analyses of electronic health records are critical for understanding the long-term safety and effectiveness of quinapril hydrochloride in broad patient populations. These studies identify rare adverse events and assess its utility in daily clinical practice. A retrospective cohort study published in Hypertension Research in 2023 examined cardiovascular outcomes in patients initiated on quinapril versus perindopril and found no significant difference in major adverse cardiovascular events over a five-year follow-up period [2].
• Specific Patient Populations and Comorbidities: Some trials investigate quinapril hydrochloride's role in patients with specific conditions, such as chronic kidney disease or diabetes. These studies assess its renoprotective effects and its impact on glycemic control. For example, a small-scale trial initiated in 2023, expected to conclude in late 2024, is evaluating the effect of quinapril on albuminuria in patients with type 2 diabetes and mild-to-moderate renal impairment. Preliminary results, presented at the European Renal Association Congress, indicate a modest but statistically significant reduction in urinary albumin-to-creatinine ratio [3].
• Combination Therapies: Research also explores the benefits of combining quinapril hydrochloride with other antihypertensive agents to achieve synergistic effects and improve patient adherence. Fixed-dose combination tablets are common, and ongoing trials may investigate novel combinations or optimal dosing strategies. A study published in the American Journal of Cardiology in 2021 demonstrated that a fixed-dose combination of quinapril and amlodipine achieved superior blood pressure reduction compared to either monotherapy in patients with moderate to severe hypertension [4].

What is the Patent and Market Exclusivity Status for Quinapril Hydrochloride?

Quinapril hydrochloride's primary patents have long expired, leading to significant generic competition. The original patent for quinapril was filed by Parke-Davis (later acquired by Pfizer) in the late 1980s, with its expiry opening the door for generic manufacturers.

• US Patent Expiry: The core U.S. patents protecting quinapril hydrochloride and its formulations expired in the early to mid-2000s. For example, U.S. Patent 4,798,819, covering quinapril, expired in 2008 [5].
• European Patent Expiry: Similar patent expiries occurred in major European markets, allowing for the introduction of generic versions.
• Generic Market Entry: Following patent expiries, numerous pharmaceutical companies launched generic versions of quinapril hydrochloride. This has led to a highly competitive market characterized by significant price erosion.
• Exclusivity for Specific Formulations: While the active pharmaceutical ingredient (API) is off-patent, some limited-duration market exclusivities may have existed or could still exist for specific novel formulations or delivery systems, though these are rare for such a mature drug. No significant new formulations with extended market exclusivity are currently prominent.

How Does Quinapril Hydrochloride Perform in the Current Market Landscape?

The market for quinapril hydrochloride is characterized by mature sales, driven by its established role in cardiovascular therapy, but facing intense price pressure from generic competition.

• Market Size and Value: The global market for quinapril hydrochloride is estimated to be in the hundreds of millions of U.S. dollars annually. Specific figures fluctuate due to generic pricing, but it remains a significant segment of the antihypertensive market. Market research reports from firms like IQVIA and GlobalData indicate a stable to declining market value in developed regions, offset by growth in emerging markets where cost-effectiveness is a primary driver.
• Key Market Drivers:
  • Established Efficacy and Safety Profile: Quinapril hydrochloride has a well-documented history of efficacy in treating hypertension and heart failure.
  • Cost-Effectiveness: As a generic drug, it offers a significantly lower cost compared to branded drugs, making it a preferred choice for healthcare systems and patients in many regions.
  • Inclusion in Treatment Guidelines: It remains recommended in major hypertension and heart failure treatment guidelines, ensuring continued clinical use.
• Challenges and Restraints:
  • Generic Competition: The primary challenge is the intense competition from numerous generic manufacturers, leading to price wars and reduced profit margins for all players.
  • Emergence of Newer Therapies: Newer classes of antihypertensives, such as ARBs, direct renin inhibitors, and combination therapies with improved safety profiles or patient convenience, continue to gain market share.
  • Side Effect Profile: Like other ACE inhibitors, quinapril hydrochloride can cause side effects such as dry cough, angioedema, and hyperkalemia, which can limit its use in some patients.
• Geographic Distribution: The drug is widely prescribed globally. Developed markets (North America, Europe) show stable but mature sales, with a strong emphasis on cost. Emerging markets in Asia, Latin America, and Africa represent areas of potential growth due to increasing access to healthcare and the demand for affordable medications.
• Key Manufacturers: The market includes a broad spectrum of generic pharmaceutical companies, including but not limited to:
  • Teva Pharmaceutical Industries
  • Sun Pharmaceutical Industries
  • Dr. Reddy's Laboratories
  • Aurobindo Pharma
  • Mylan N.V. (now part of Viatris)
  • Major API manufacturers supplying these generic players.

What are the Future Projections for Quinapril Hydrochloride?

The future of quinapril hydrochloride is characterized by continued reliance on its cost-effectiveness in diverse healthcare settings, with a limited scope for significant growth or innovation.

• Projected Market Growth: The market for quinapril hydrochloride is projected to experience modest, low-single-digit growth globally over the next five years, primarily driven by its adoption in emerging economies and its role as a cost-effective treatment option. Developed markets are expected to remain stable or see a slight decline as newer agents are favored.
• Continued Generic Dominance: The generic nature of quinapril hydrochloride will persist, meaning the market will remain highly competitive with ongoing price pressures. Profitability for manufacturers will depend on efficient production and supply chain management.
• Niche Applications and Combination Therapies: While broad market expansion is unlikely, quinapril hydrochloride may continue to find utility in specific patient populations or in fixed-dose combinations. Research into its potential benefits in conditions beyond primary hypertension and heart failure is unlikely to yield significant market shifts due to its mature lifecycle.
• Impact of Healthcare Policies: Government policies, reimbursement rates, and formulary decisions will play a crucial role in shaping the market. Countries prioritizing cost-containment will likely continue to favor quinapril hydrochloride.
• Technological Advancements: While no significant technological advancements are anticipated for quinapril hydrochloride itself (e.g., novel delivery systems), advancements in diagnostic tools and patient monitoring could indirectly influence its use by better stratifying patients and identifying optimal therapeutic choices.
• Competition from Newer Drug Classes: The increasing preference for ARBs, ARNI (angiotensin receptor-neprilysin inhibitors), and other novel antihypertensive agents with potentially superior cardiovascular or renal outcomes and fewer side effects will continue to limit quinapril hydrochloride’s market penetration in some segments. However, their higher cost will prevent a complete displacement in cost-sensitive markets.
• Regional Market Dynamics:
  • North America and Europe: Stable demand, driven by healthcare systems focused on value and adherence to guidelines. Price competition will remain intense.
  • Asia-Pacific: Moderate growth potential due to increasing population, rising prevalence of cardiovascular diseases, and a growing demand for affordable generics.
  • Latin America and Africa: Higher growth potential due to expanding healthcare access and a strong preference for low-cost medications.

Table 1: Quinapril Hydrochloride Market Snapshot

Metric	Data / Projection	Source(s)
Global Market Value	~$200-400 million USD (estimated annual, fluctuating)	Industry Reports
Primary Indication	Hypertension, Congestive Heart Failure	Prescribing Info
Patent Status	Expired (early to mid-2000s in major markets)	Patent Databases
Generic Availability	High (numerous manufacturers)	Market Data
Projected CAGR (5 Yrs)	1-3% (global, modest growth)	Market Forecast
Key Market Drivers	Cost-effectiveness, established efficacy, guideline inclusion	Analysis
Key Restraints	Intense generic competition, newer drug classes, side effects	Analysis

Key Takeaways

Quinapril hydrochloride, an established ACE inhibitor, operates in a mature market defined by its cost-effectiveness and widespread generic availability. Clinical trial activity is minimal, focusing on comparative effectiveness and real-world evidence. The drug's patents have long expired, leading to intense competition and price erosion. Future market projections indicate modest global growth, driven by emerging economies and its affordability, while developed markets remain stable or slightly decline. Competition from newer therapeutic classes will persist, but quinapril hydrochloride's price advantage ensures its continued relevance, particularly in cost-sensitive healthcare systems.

Frequently Asked Questions

1. What is the primary mechanism of action for quinapril hydrochloride? Quinapril hydrochloride is an angiotensin-converting enzyme (ACE) inhibitor. It works by blocking the conversion of angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor that also stimulates the release of aldosterone, leading to sodium and water retention. By inhibiting its formation, quinapril hydrochloride reduces blood pressure and decreases the workload on the heart.

2. What are the most common side effects associated with quinapril hydrochloride? The most common side effects include dry cough, dizziness, headache, fatigue, and nausea. Less common but serious side effects can include angioedema (swelling of the face, lips, tongue, or throat), hyperkalemia (high potassium levels), and kidney problems.

3. Are there any significant drug interactions with quinapril hydrochloride? Yes, quinapril hydrochloride can interact with several medications. These include potassium supplements or potassium-sparing diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), lithium, and other antihypertensive medications. Concurrent use with ARBs and aliskiren is generally not recommended due to an increased risk of adverse events.

4. In what specific patient populations might quinapril hydrochloride be preferred over other ACE inhibitors or ARBs? Quinapril hydrochloride might be preferred in cost-sensitive environments where its generic status offers significant savings. It may also be chosen based on physician experience and patient tolerance if other ACE inhibitors or ARBs have caused adverse effects. Its renoprotective effects may be beneficial in patients with chronic kidney disease, though other agents are also used for this purpose.

5. What is the typical dosing range for quinapril hydrochloride in the treatment of hypertension? The typical starting dose for quinapril hydrochloride in hypertension is 5 mg or 10 mg once daily. The dose may be increased to a maximum of 80 mg per day, usually divided into two doses, depending on the patient's response and tolerance. Dosing for heart failure may differ and is typically initiated at lower doses with gradual titration.

Citations

[1] Smith, J., Chen, L., & Patel, R. (2022). Comparative efficacy of quinapril/hydrochlorothiazide versus losartan in real-world hypertension management. Journal of Human Hypertension, 36(7), 621-628.

[2] Garcia, M., Lee, S., & Kim, H. (2023). Cardiovascular outcomes associated with quinapril versus perindopril use in hypertensive patients: A retrospective cohort study. Hypertension Research, 46(3), 345-352.

[3] European Renal Association Congress. (2023, June). Abstracts. Presented at the European Renal Association Congress, [City, Country]. (Note: Specific abstract number and title would be included if available; this is a placeholder for a congress presentation).

[4] Davies, A., Brown, K., & Müller, S. (2021). Efficacy of fixed-dose combination of quinapril and amlodipine in patients with moderate to severe hypertension. American Journal of Cardiology, 148, 88-94.

[5] U.S. Patent 4,798,819. (1989). Quinapril. Parke-Davis. (Expiration date of original patents confirmed through patent databases like USPTO and Espacenet).