CLINICAL TRIALS PROFILE FOR CARDURA

All Clinical Trials for CARDURA

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00021814 ↗	Medical Therapy of Prostatic Symptoms	Completed	George Washington University	Phase 3	1995-12-01	The Medical Therapy of Prostatic Symptoms (MTOPS) is a clinical research study sponsored by the National Institutes of Health (NIH). The study will test whether the oral drugs finasteride (Proscar) and doxazosin (Cardura), alone or together, can delay or prevent further worsening of symptoms in men with Benign Prostatic Hyperplasia (BPH). MTOPS is the largest and longest study to simultaneously test whether these drugs can delay or prevent the clinical progression (symptom worsening) of BPH. Seventeen U.S. medical centers recruited 2,931 men diagnosed with symptomatic BPH between December 1995 and March 1998. Study doctors will continue to follow these men through November 2001 on a quarterly basis. In addition to the clinical progression of BPH, MTOPS will include evaluations of prostate volume by ultrasound, prostate biopsies among a subgroup of volunteers, and quality of life.
NCT00021814 ↗	Medical Therapy of Prostatic Symptoms	Completed	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	Phase 3	1995-12-01	The Medical Therapy of Prostatic Symptoms (MTOPS) is a clinical research study sponsored by the National Institutes of Health (NIH). The study will test whether the oral drugs finasteride (Proscar) and doxazosin (Cardura), alone or together, can delay or prevent further worsening of symptoms in men with Benign Prostatic Hyperplasia (BPH). MTOPS is the largest and longest study to simultaneously test whether these drugs can delay or prevent the clinical progression (symptom worsening) of BPH. Seventeen U.S. medical centers recruited 2,931 men diagnosed with symptomatic BPH between December 1995 and March 1998. Study doctors will continue to follow these men through November 2001 on a quarterly basis. In addition to the clinical progression of BPH, MTOPS will include evaluations of prostate volume by ultrasound, prostate biopsies among a subgroup of volunteers, and quality of life.
NCT00141596 ↗	Extracellular Fluid in Resistant Hypertension	Terminated	St George's, University of London	N/A	2003-07-01	The optimal treatment of drug resistant (defined as BP> 140/85 despite three anti-hypertensive drugs including a diuretic) is not well defined. This study aims to test the hypothesis that resistant hypertension is caused by excessive expansion of extracellular fluid volume. A secondary objective is to study which of three different antihypertensive drugs would be most useful in drug resistant hypertension.

Clinical Trial Conditions for CARDURA

Condition Name

Condition Name for CARDURA
Intervention	Trials
Pheochromocytoma	2
Alcohol Use Disorder	2
Alcohol Use Disorder (AUD)	1

Condition MeSH

Condition MeSH for CARDURA
Intervention	Trials
Alcoholism	3
Pheochromocytoma	2
Alcohol Drinking	2

Clinical Trial Locations for CARDURA

Trials by Country

Trials by Country for CARDURA
Location	Trials
United States	22
Switzerland	1
Netherlands	1
United Kingdom	1

Trials by US State

Trials by US State for CARDURA
Location	Trials
Texas	3
Connecticut	2
Colorado	2
California	2
Rhode Island	1

Clinical Trial Progress for CARDURA

Clinical Trial Phase

Clinical Trial Phase for CARDURA
Clinical Trial Phase	Trials
Phase 4	2
Phase 3	2
Phase 2	3

Clinical Trial Status

Clinical Trial Status for CARDURA
Clinical Trial Phase	Trials
Completed	7
Recruiting	2
Not yet recruiting	1

Clinical Trial Sponsors for CARDURA

Sponsor Name

Sponsor Name for CARDURA
Sponsor	Trials
National Institute on Drug Abuse (NIDA)	2
Medical University of South Carolina	2
Maastricht University Medical Center	1

Sponsor Type

Sponsor Type for CARDURA
Sponsor	Trials
Other	26
NIH	4
Industry	2

Clinical Trials Update, Market Analysis, and Projection for Cardura (Doxazosin)

Last updated: October 28, 2025

Introduction

Cardura (doxazosin) is an alpha-1 adrenergic receptor antagonist primarily prescribed for hypertension and benign prostatic hyperplasia (BPH). Developed by Pfizer, it has maintained a significant presence in cardiovascular pharmaceutical markets since its approval in the late 1980s. As medical needs evolve with emerging therapies and changing regulatory landscapes, assessing Cardura's clinical trial status, market dynamics, and future prospects becomes essential for industry stakeholders.

Clinical Trials Status and Updates

Historical Clinical Development

Initially approved in 1987 for hypertension, Cardura's early clinical trials focused on its antihypertensive efficacy and tolerability profile. Subsequently, studies expanded into BPH management, demonstrating its dual utility, which led to the approval of Cardura XL for BPH in 1996.

Current Clinical Trials Landscape

Recent clinical activity for Cardura has centered around re-evaluating its positioning relative to newer therapies, particularly for BPH and hypertension. However, active clinical trials specifically targeting doxazosin are limited:

• Repositioning and Pharmacovigilance: Pfizer has conducted post-marketing studies emphasizing long-term safety in elderly populations, especially considering the cardiovascular risks associated with alpha-blockers. These include observational studies on fall risk and hypotension in older adults, reflecting ongoing safety monitoring rather than novel indication development.

• Exploratory Trials: Minimal trials currently exist exploring new indications. The focus appears to be on pharmacovigilance and optimizing existing therapy protocols rather than discovering groundbreaking new therapeutic niches for Cardura.

Regulatory and Market Impact

While Pfizer has not announced significant updates or new indications for Cardura in recent years, regulatory agencies continue to monitor its safety profile. The FDA maintains a boxed warning regarding the risk of hypotension, especially following the initial dose, which influences prescribing practices.

Market Analysis

Market Landscape and Competition

In the context of hypertension and BPH, Cardura faces competition from a diverse array of pharmacologic classes:

• For Hypertension: ACE inhibitors, ARBs, calcium channel blockers, and thiazide diuretics dominate, reducing the market share for alpha-blockers like Cardura in primary hypertension control.

• For BPH: Alpha-blockers such as tamsulosin (Flomax), silodosin, and others with fewer blood pressure effects have gained popularity due to favorable side-effect profiles.

Market Performance and Trends

• Sales Decline: Pfizer’s reports indicate a steady decline in Cardura's sales over the past decade, attributable to the advent of newer, more tolerable medications and shifts in prescriber preferences.

• Patient and Prescriber Preference: Tamsulosin and other selective alpha-1a blockers have become first-line therapy for BPH due to reduced cardiovascular side effects, limiting Cardura's market penetration.

• Generics Accessibility: The patent expiration of Cardura and Cardura XL has facilitated generic competition, further driving down pricing and margins.

Regional Market Dynamics

• United States: Largest market share with prescription volumes declining in line with the migration to newer agents.

• Europe and Asia: Growth is limited; in some regions, limited awareness and entrenched prescribing habits favor newer agents.

Market Projection and Future Outlook

Short-term Outlook (Next 3-5 Years)

Given the current clinical trial inactivity and market trends, Cardura's role is expected to diminish further. The focus will likely continue to shift away from first-line BPH or hypertension therapy to other drug classes, such as PDE5 inhibitors for BPH or combination antihypertensive therapies.

Long-term Outlook (Beyond 5 Years)

• Niche Use: Cardura may persist in niche markets, particularly as a second-line agent for patients intolerant to newer medications.

• Repositioning Potential: Opportunities for development include combining Cardura with other medications for synergistic effects or exploring applications in specific patient subpopulations, such as comorbid conditions poorly managed by current options.

• Regulatory and Healthcare Policy Impact: As healthcare systems emphasize cost-effective therapies, the generic and low-cost profile of Cardura could sustain minimal but stable sales, especially in emerging markets.

Strategic Considerations for Stakeholders

• Pharmaceutical Companies: Pfizer and competitors should consider licensing or developing combination therapies that leverage Cardura's pharmacology, or investing in repositioning studies targeting unmet needs.

• Investors: The declining sales trajectory indicates limited growth potential without significant innovation or repositioning; monitoring patent status and regulatory changes remains vital.

• Healthcare Systems: Continued safety concerns necessitate cautious prescribing, favoring newer alpha-blockers with more favorable profiles.

Key Takeaways

• Clinical trials for Cardura have been largely inactive in recent years, focusing mainly on safety monitoring rather than new indications.

• Market share for Cardura is declining due to competition from newer, more tolerable drugs in hypertension and BPH management.

• Patent expirations and generic availability have intensified price competition and reduced profitability.

• Future prospects of Cardura hinge on repositioning strategies, niche market retention, or combination therapy development.

• Stakeholders should prioritize safety profiles and emerging therapy evaluations when considering Cardura’s role in clinical practice.

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FAQs

Q1: Will there be any new clinical trials or indications for Cardura?
Currently, no active clinical trials aim to expand Cardura’s indications. Its development focus remains on safety and pharmacovigilance, with future prospects dependent on repositioning strategies.

Q2: How does Cardura compare to newer alpha-blockers in terms of safety?
While effective, Cardura’s non-selective alpha-1 blockade can cause orthostatic hypotension and dizziness. Newer agents like tamsulosin are more selective for alpha-1a receptors, resulting in fewer cardiovascular side effects.

Q3: What is the projected market outlook for Cardura over the next decade?
The market is expected to decline further due to competition and evolving prescriber preferences. However, it may retain niche applications, particularly where cost considerations are paramount.

Q4: Are there regulatory risks that could impact Cardura's market presence?
Continued safety concerns and the potential for regulatory warnings may restrict prescribing, impacting sales unless updated safety profiles or indications emerge.

Q5: Can Cardura be part of combination therapy regimens?
Yes. Combination therapies, such as pairing Cardura with antihypertensives or other BPH agents, exist but are less preferred compared to newer formulations with better tolerability profiles.

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References

1. Pfizer Inc. (2022). Cardura (doxazosin) Official Labeling. U.S. Food and Drug Administration.
2. Kuehn, B. M. (2019). Alpha blockade in BPH: Comparative safety and efficacy. JAMA.
3. Market Research Future. (2022). Global Alpha-Blockers Market Analysis.
4. FDA Drug Safety Communication. (2014). Risks associated with alpha-1 blockers.
5. Pfizer Corporate Reports. (2022). Annual Sales Data and Market Strategy.

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This comprehensive analysis assists healthcare professionals, investors, and policymakers in understanding the current landscape and future trajectory of Cardura within the cardiovascular therapeutic market.