Protective bubble around a brain illustrating the prevention of stroke with Losartan and Captopril.

Stroke Breakthrough: Can Losartan and Captopril Halt Brain Hemorrhage Without Lowering Blood Pressure?

Lena Voss in Health & Wellness November 2025 • 5 min read.

"New research explores how post-stroke treatments could revolutionize recovery by preventing further brain damage, offering hope for improved outcomes and long-term health"

Stroke remains a leading cause of long-term disability and death worldwide, affecting millions each year. One of the most dangerous complications following a stroke is hemorrhagic expansion, where bleeding in the brain continues to worsen, leading to increased damage and poorer outcomes. Traditional treatments often focus on lowering blood pressure, but new research suggests there may be other ways to halt this deadly process.

A groundbreaking study published in "Vascular Pharmacology" explores the potential of two common medications, losartan and captopril, to arrest hemorrhagic expansion in the brain after a stroke without significantly lowering blood pressure. This intriguing finding could revolutionize stroke treatment, offering new hope for preventing further brain damage and improving patient recovery.

This article delves into the details of this innovative research, examining how losartan and captopril work, the implications of their effects on hemorrhagic expansion, and what this could mean for the future of stroke care. Whether you’re a healthcare professional, a stroke survivor, or simply interested in the latest medical breakthroughs, this is a must-read.

How Can Losartan and Captopril Protect the Brain After a Stroke?

Protective bubble around a brain illustrating the prevention of stroke with Losartan and Captopril.

The study, led by John S. Smeda and his team, investigated the impact of losartan and captopril on stroke-prone hypertensive rats (SHRsp). These rats, which are genetically predisposed to high blood pressure and strokes, provide a valuable model for understanding how these treatments might work in humans. The researchers assessed the ability of post-stroke losartan and captopril to attenuate hematoma expansion and plasma extravasation after intracerebral hemorrhagic stroke. Cerebrum volume, herniation and surface areas exhibiting new and old hemorrhages, and albumin extravasation were measured prior to and after stroke, and following 30 and 60 days of post-stroke losartan or captopril treatment in Evans Blue dye perfused brains.

Losartan and captopril are well-known medications used to treat high blood pressure, but their potential benefits in stroke recovery extend beyond their blood pressure-lowering effects. Losartan is an angiotensin II receptor blocker (ARB), while captopril is an angiotensin-converting enzyme (ACE) inhibitor. Both drugs interfere with the renin-angiotensin system (RAS), a hormonal system that regulates blood pressure and fluid balance.

Arresting Hemorrhagic Expansion: Both losartan and captopril were found to halt the expansion of bleeding in the brain after a stroke. This is crucial because the continued growth of a hematoma (blood clot) can compress brain tissue, leading to further damage and disability.
Preventing Plasma Extravasation: The medications also reduced plasma extravasation, the leakage of fluid from blood vessels into the brain. This leakage can cause swelling and increased pressure, exacerbating the effects of the stroke.
No Significant Blood Pressure Reduction: Perhaps the most surprising finding was that these benefits occurred without significantly lowering blood pressure. This suggests that losartan and captopril are working through mechanisms other than simply reducing blood pressure, potentially targeting the underlying causes of hemorrhagic expansion.

Lesion morphology was studied in serial sections. Losartan or captopril treatment initiated at stroke prevented death for 60 days without lowering BP. Stroke onset was associated with the development and subsequent expansion of cerebrum volume, herniation, hematoma and plasma albumin extravasation. Losartan arrested cerebral volume expansion and herniation, and produced the virtual disappearance of hematoma and plasma albumin extravasation after 60 days. Captopril treatment equally attenuated cerebral herniation and hematoma expansion but was less effective in stopping albumin extravasation and allowed cerebrum volume to increase to post-stroke levels after 60 days of treatment. Both treatments resolved hematomas into cortical fluid filled spaces and prevented new hemorrhage formation.

What Does This Mean for the Future of Stroke Treatment?

The findings of this study offer exciting new avenues for stroke treatment and recovery. By demonstrating that losartan and captopril can protect the brain from further damage without relying solely on blood pressure reduction, researchers have opened the door to more targeted and effective therapies. While further research is needed to confirm these results in humans and fully understand the underlying mechanisms, the potential benefits for stroke survivors are immense. This research emphasizes the importance of continued exploration and innovation in the fight against stroke, offering hope for improved outcomes and a better quality of life for those affected.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.vph.2018.08.006, Alternate LINK

Title: Post-Stroke Losartan And Captopril Treatments Arrest Hemorrhagic Expansion In Shrsp Without Lowering Blood Pressure

Subject: Pharmacology

Journal: Vascular Pharmacology

Publisher: Elsevier BV

Authors: John S. Smeda, Danielle Watson, Jennifer Stuckless, Amit Negandhi

Published: 2018-12-01

Everything You Need To Know

How do losartan and captopril protect the brain from further damage after a stroke?

The study demonstrated that both losartan and captopril could halt the expansion of bleeding in the brain, known as hemorrhagic expansion, after a stroke. This action helps prevent further brain damage by reducing compression from the hematoma. Additionally, they reduced plasma extravasation, the leakage of fluid from blood vessels into the brain, which can cause swelling and increased pressure. A key finding was that these benefits occurred without significantly lowering blood pressure, suggesting mechanisms beyond simple blood pressure reduction are at play.

What are losartan and captopril, and how do they interact with the renin-angiotensin system (RAS)?

Losartan is classified as an angiotensin II receptor blocker (ARB), while captopril is an angiotensin-converting enzyme (ACE) inhibitor. Both drugs impact the renin-angiotensin system (RAS), which is a hormonal system crucial for regulating blood pressure and fluid balance. By interfering with the RAS, losartan and captopril can influence vascular function and reduce hemorrhagic expansion following a stroke. However, the precise mechanisms by which these drugs act independently of blood pressure reduction require further investigation.

What specific effects did losartan and captopril have on the brains of stroke-prone hypertensive rats (SHRsp) in the study?

The research showed that losartan and captopril treatments initiated post-stroke prevented death in stroke-prone hypertensive rats (SHRsp) for 60 days without lowering blood pressure. Specifically, losartan arrested cerebral volume expansion and herniation, leading to the virtual disappearance of hematoma and plasma albumin extravasation after 60 days. Captopril was equally effective in attenuating cerebral herniation and hematoma expansion but less effective in stopping albumin extravasation, allowing cerebrum volume to increase to post-stroke levels after 60 days. Both treatments resolved hematomas into cortical fluid-filled spaces and prevented new hemorrhage formation.

What are the potential implications of the study's findings for future stroke treatment and recovery?

The findings suggest that future stroke treatments could target mechanisms beyond blood pressure reduction to prevent further brain damage. By demonstrating the effectiveness of losartan and captopril in arresting hemorrhagic expansion without significant blood pressure reduction, researchers have opened the door to more targeted therapies. These could potentially improve outcomes and the quality of life for stroke survivors by reducing long-term disability and preventing further complications.

What aspects of stroke recovery were not addressed in this study concerning losartan and captopril?

While the study focused on the effects of losartan and captopril on hemorrhagic expansion and plasma extravasation, several other aspects of stroke recovery were not directly addressed. For instance, the research did not extensively cover rehabilitation strategies, the impact of these drugs on different types of stroke (ischemic vs. hemorrhagic), or the potential long-term cognitive and motor function outcomes. Further studies are needed to explore these areas and to validate the findings in human clinical trials to fully understand the comprehensive benefits and limitations of losartan and captopril in stroke treatment.