Can Viagra cause a stroke?

Many men wonder if there’s a link between Viagra and the risk of stroke. Erectile dysfunction can have a significant impact on quality of life. However, many men are hesitant to take Viagra because of concerns about the risk of stroke. In this article, we will explore the evidence to find out if there is any truth to the concern that Viagra can trigger a stroke.

Before we start to investigate whether there is any link between taking Viagra and the potential risk for stroke, let’s cover some basics about erectile dysfunction and how Viagra works.

Understanding erectile dysfunction: Causes, risks, and treatment

Let’s start with the basics. Erectile dysfunction (ED), formerly known as impotence, is the inability to achieve or maintain an erection firm enough for satisfying sexual activity.[1] While there’s no strict rule on how long ED must last to be diagnosed, many experts suggest the issue should persist for about six months. Erectile dysfunction is common, especially among men over 40, and its likelihood increases with age and certain health conditions.[2]

Erectile dysfunction can sometimes be a sign of underlying health issues, including cardiovascular disease, diabetes, high cholesterol, and high blood pressure.[3] Essentially, any condition that disrupts blood flow, nerve function, hormones, or erectile tissue can contribute to ED. For instance, problems with blood vessel lining, known as endothelial dysfunction, are often found in men with erectile dysfunction.[4] Basically, erectile dysfunction is the canary in the mineshaft, providing you with an early warning that all is not right with your blood vessels.

While physical factors cause most cases of ED, psychological aspects can also play a role, particularly in younger men. Even when erectile dysfunction has a physical cause, it can still lead to emotional stress, impacting self-esteem, relationships, and mental health. For an erection to occur, both the body and mind need to be in sync.

The good news is that ED is highly treatable. Many options are available to help men improve their quality of life and regain confidence. Consulting a healthcare provider is the best way to find the cause of erectile dysfunction. So, if you still have any concerns after reading this article, please email us at info@medicalmojo.co.uk.

How does Viagra work?

Now that we understand erectile dysfunction let’s talk about Viagra, the famous little blue pill. Viagra (sildenafil) works by boosting blood flow to the penis, making it easier to get and maintain an erection when sexually aroused. It does this by blocking an enzyme called phosphodiesterase type 5 (PDE5), which usually breaks down a molecule called cyclic guanosine monophosphate (cGMP).

cGMP is essential because it relaxes the smooth muscles in blood vessels, allowing them to widen and let more blood into the penis. By blocking PDE5, Viagra keeps cGMP levels higher, leading to better blood flow and a more robust, longer-lasting erection. However, Viagra doesn’t cause an erection on its own—you still need to be sexually aroused to kick off the process.[5]

Viagra is mainly prescribed for men with erectile dysfunction (ED) and has been proven to be effective and safe in many studies.[6] To sum it up, Viagra works by improving blood flow to the penis, helping with erection quality during arousal.

Viagra’s effect on blood pressure: What the research says

When you take Viagra, it dilates your blood vessels, increasing blood flow to your penis and other areas of your body, which in turn affects your blood pressure. Blood pressure measures the force of blood pushing against artery walls as your heart pumps.

A study was conducted to see if Viagra (sildenafil) significantly lowers blood pressure in men. Researchers monitored the blood pressure of 49 men, including 22 with hypertension (high blood pressure) and 27 with normal blood pressure, across two nights. On one night, the men took no medication, and on the other night, they took 100 mg of Viagra. Blood pressure and heart rate readings were taken regularly for three hours while awake and every 30 minutes while they slept.

Results showed that Viagra led to slight decreases in blood pressure. Systolic blood pressure (SBP), the blood pressure when the heart contracts and forces blood into the arteries, dropped by 6.0 mm Hg. Diastolic blood pressure (DBP), the blood pressure when the heart relaxes and fills with blood, fell by 4.5 mm Hg, and overall mean arterial pressure by 5.3 mm Hg.

These reductions were similar in men with and without high blood pressure, but men aged 49 and older experienced slightly more significant blood pressure drops than younger men. Despite these drops in blood pressure, none of the participants had symptoms of hypotension (low blood pressure). About 22.7% of men with hypertension and 3.7% of those without hypertension saw a decrease in SBP of 20 mm Hg or more, but these changes weren’t linked to any discomfort.[7]

Overall, the study found that Viagra causes minor and clinically insignificant drops in blood pressure in both normotensive (normal BP) and hypertensive men, whether they were active or resting. This suggests that, when taken as directed, Viagra is safe for men of all ages, including those with high blood pressure.

For men with cardiovascular conditions or who use nitrate medications, Viagra’s effect on blood pressure could lead to serious health risks, so caution and medical guidance are essential. We learn more about why this drastic drop in blood pressure when combining Viagra with nitrates is so dangerous later on in this article.

Viagra and stroke risk: What recent studies say

Viagra (sildenafil) is generally safe for most men and isn’t commonly linked to a high risk of stroke. However, the reason why taking Viagra was thought to cause a stroke was the emerging evidence that falls in blood pressure were associated with ischaemic stroke; this is where there is not enough blood flowing to the brain.

Sildenafil (Viagra) works by blocking an enzyme called PDE5, which increases a chemical called cGMP. This helps relax blood vessels, improving blood flow, especially in the penis, to support erections. PDE5 is not only found in the penis but also in other parts of the body, like the lungs and brain.[8] This broad action means sildenafil can have effects beyond just treating erectile dysfunction, and we are only just beginning to discover new uses for this blockbuster drug.

Sildenafil increases blood flow to certain areas of the brain in people with vascular health risks (such as high blood pressure). However, in stroke patients, it may cause mixed blood flow effects: it can either increase blood flow to some areas or decrease it in others, unrelated to the original stroke location.

This decrease in blood flow, called a “steal effect,” could potentially worsen brain perfusion or blood flow in stroke patients, requiring caution in using sildenafil if there’s a history of stroke. [9] The brain’s ability to balance blood flow under sudden changes in blood pressure, known as cerebral autoregulation, may be impaired after a stroke, making such patients more vulnerable.[10]

Viagra and headaches

One possible side effect of sildenafil (Viagra) is headaches. This happens because the medication can cause blood vessels in the brain to widen, allowing for increased blood flow. So, if you have a headache when reading this, you know it’s because more blood is flowing into your brain. However, studies on people with migraines suggest that sildenafil does not significantly dilate the main brain arteries. It’s thought that sildenafil may not raise levels of the molecule cGMP enough in the brain’s arteries to cause noticeable expansion. [11]

Viagra and Transient Ischaemic Attacks (TIA)

Other rare brain-related effects have been reported, like transient ischemic attacks (TIAs) or mini-strokes. [12] TIAs may occur in some people, especially if they have other risk factors for stroke. This might happen because sildenafil can lower blood pressure, especially in those with blood vessel issues, potentially causing brief blood flow reductions in the brain.

Viagra and seizures

In rare cases, sildenafil has also been associated with seizures, especially in people with conditions like high blood pressure. Sildenafil can raise levels of certain brain chemicals, like glutamate, which is an excitatory neurotransmitter that might trigger seizures in susceptible people. [13]

Viagra and amnesia

A few cases of temporary memory loss (amnesia) have also been noted, possibly because reduced blood flow in specific brain areas may lead to brief memory lapses. [14]

Viagra and the “Steal effect.”

Finally, there’s a possibility that sildenafil might, under specific conditions, affect blood flow in the brain unevenly (a phenomenon called the “steal effect”), which could lead to areas with reduced blood flow. [15] It’s a case of robbing Peter to pay Paul; you can’t add any more blood to the circulation, so if more blood flows to the penis, there is less of it to flow to the brain.

This effect, however, requires more study, especially in stroke patients. Further research is needed to understand if long-acting PDE5 inhibitors (the category sildenafil belongs to) may have similar or different effects on the brain.

Should Viagra be used in men who have just had a stroke or heart attack or suffer from low blood pressure?

Based on current safety data, there’s no evidence linking sildenafil (Viagra) to an increased risk of serious heart problems, like heart attacks, in men with erectile dysfunction (ED). Studies show that sildenafil does not raise the risk of serious cardiovascular events. Additionally, sildenafil appears to be just as safe for men with ED who also have conditions like diabetes, high blood pressure, or other heart issues as it is for men without these conditions.

However, sildenafil hasn’t been well-studied in men with very low blood pressure (below 90/50 mmHg) or those who recently had a heart attack or stroke. Because of this, it’s recommended that men with these specific conditions avoid using sildenafil, as the risks are not fully understood for them. [16]

Viagra drug interactions

Nitrates, such as nitroglycerin (GTN), are primarily used to treat angina, a type of chest pain caused by reduced blood flow to the heart. By relaxing and widening blood vessels, nitrates improve blood flow and relieve pain associated with angina.

Since Viagra also dilates blood vessels, taking it with nitrates can lead to a severe drop in blood pressure, increasing the risk of dizziness, fainting, or even serious cardiovascular events like heart attack or stroke. Some of the most common nitrates include nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate, all of which can have dangerous interactions with Viagra.

Additionally, it’s crucial to be aware of other medications that may interact with Viagra, such as riociguat (Adempas®), alpha-blockers, and certain blood pressure medications. Supplements and recreational drugs like nitrites (“poppers”) should also be avoided while taking Viagra to prevent adverse effects.

In addition, there are certain other medications like certain antibiotics (such as erythromycin and clarithromycin), antifungal drugs (like ketoconazole and itraconazole), HIV treatments, can slow down the liver enzyme CYP3A4. This enzyme helps break down Viagra, so if it’s slowed, the levels of the little blue pill can build up in the body, intensifying both its positive and negative effects. People taking these medications might need a lower starting dose of Viagra to stay safe.

Another class of drugs called protease inhibitors, which are often used to treat HIV, can also significantly increase Viagra levels in the body. Because of this, patients on protease inhibitors may need a carefully adjusted, lower dose of Viagra to prevent unwanted side effects.[17]

By understanding these interactions and discussing them with a healthcare provider, patients can use Viagra safely while minimising adverse effects, particularly those with cardiovascular or complex medication regimens.

If you’re unsure about your medications, consult the pharmacy team at medicalmojo.co.uk, who will let you know if Viagra is safe for you. Email the team at info@medicalmojo.co.uk.

The safety profile of Viagra (Sildenafil) and key considerations for cardiovascular health

Viagra, a commonly prescribed treatment for erectile dysfunction (ED), has proven both effective and generally safe for most men. By enhancing blood flow, primarily to the penis, Viagra helps men achieve and maintain an erection. While side effects in healthy individuals are typically mild, including headaches, facial flushing, and slight drops in blood pressure, patients with cardiovascular concerns or certain medications need to exercise caution. For most users without these risks, Viagra remains a reliable option for erectile dysfunction treatment.

Important precautions for cardiovascular patients

Men with certain heart conditions, including active heart disease, congestive heart failure, recent heart attack or stroke, or those on complex blood pressure medications should use Viagra with caution and consult their healthcare provider for personalised guidance. Alternatively, email the medicalmojo.co.uk pharmacy team at info@medicalmojo.co.uk.

Patients on multiple blood pressure medications or those with very low blood pressure may need close monitoring or alternative treatments. Though Viagra’s blood-pressure-lowering effects are generally mild, patients with cardiovascular disease or those on nitrate therapy should be aware of potential risks, especially with medications affecting blood pressure regulation.[18]

Recognising stroke symptoms and the importance of immediate action

A stroke occurs when blood flow to part of the brain is interrupted, depriving brain cells of oxygen. This can cause brain cells to die within minutes, so knowing the symptoms of a stroke and acting fast can make a huge difference. Here are common symptoms:

• Dizziness
• Nausea or vomiting
• Slurred or abnormal speech
• Numbness in the face, arm, or leg (often on one side)
• Weakness on one side of the body
• Loss of balance or coordination
• Sudden, severe headache

If you suspect someone is having a stroke, remember the FAST acronym to act quickly:

• F – Face: Ask the person to smile. Does one side of their face droop?
• A – Arms: Ask them to raise both arms. Does one arm drift downward?
• S – Speech: Ask them to repeat a simple phrase. Is their speech slurred or strange?
• T – Time: Call emergency services immediately if you see any of these signs. Every second counts.

Quick treatment is crucial, as untreated strokes can lead to lasting issues like memory loss, difficulty speaking, or paralysis.

Many people struggle to recognise the symptoms of a stroke, often mistaking them for less severe health issues. Studies show that while 61% of Canadians can identify at least one stroke symptom, only 33% know two, and a mere 10% know all three main symptoms outlined by the FAST mnemonic (Face, Arms, Speech, Time). [19] This gap in awareness can delay emergency calls, reducing a patient’s chance to receive timely, life-saving treatments.

In recent years, public health campaigns have increasingly promoted stroke symptom awareness. One of the most effective tools is the FAST mnemonic, widely recognised in healthcare. A systematic review found that mass media campaigns can improve symptom recognition by 20% and boost the likelihood of calling emergency services by 19%. These campaigns are also linked to a rise in the use of clot-busting drugs in stroke treatment, which can be critical in minimising long-term effects. [20]

Viagra and stroke risk: What do you need to know

Is stroke a common side effect of Viagra? Not for most men who use it as directed and avoid risky drug combinations. However, if you have a history of heart issues, extra caution is essential when using Viagra for erectile dysfunction.

In rare cases, using Viagra alongside certain medications may cause dangerously low blood pressure, which could result in an ischemic stroke. An ischemic stroke occurs when the blood flow to the brain is reduced or blocked, often due to a blood vessel obstruction. Hypotension, caused by an extreme drop in blood pressure, can reduce oxygen to the brain and increase stroke risk. There’s also a chance of haemorrhagic stroke, which involves bleeding in the brain.

To reduce these risks, always consult a health professional about your medical history and any medications you’re taking before using Viagra.

Here’s the bottom line:

For generally healthy men, the main side effects of Viagra are headaches, facial flushing, indigestion, vision changes, back pain, nausea, dizziness, nasal congestion, rash, and muscle aches. But for those with a history of heart problems or those taking nitrate medications for heart conditions, using Viagra can lead to serious complications, even death, if not managed carefully.

The most important takeaway? Be open with your healthcare provider about all the medications you’re on before starting Viagra or any ED treatment. They’ll help you understand any possible interactions, risks, or alternatives to keep you safe.

Are you curious about ED options? Explore resources and advice on our sexual health platform, and please get in touch with the medicalmojo.co.uk team at info@medicalmojo.co.uk if you are still unsure of whether Viagra is safe for you.

Why choose Medical Mojo for sexual health support?

When considering Viagra or other options to improve sexual health, getting expert advice ensures your treatment is both safe and suited to your needs. At Medical Mojo, we offer private, supportive telehealth services for men facing concerns like erectile dysfunction. Our team of experienced pharmacists, doctors, and therapists provides guidance on Viagra and other solutions so you can make informed, confident choices.

Here’s why Medical Mojo is an ideal choice for sexual health support:

• Private, judgment-free consultations from the comfort of your own home
• Personalised recommendations based on a complete review of your health profile
• Health screenings to confirm if Viagra is right for you
• Ongoing support and follow-up while using Viagra
• Clear and realistic guidance on Viagra’s effects
• Holistic advice on lifestyle changes to support sexual health
• Healthy lifestyle coaching to get your mojo back
• Personalised medicines from our expert compounding pharmacy team
• Evidence-based articles and resources on all aspects of sexual health

With Medical Mojo, you’ll gain a clear and realistic understanding of what Viagra can and cannot do for your sexual performance, helping you set healthy expectations and make well-informed treatment decisions. For personalised advice or more information, get in touch.

Disclaimer: This article is for informational purposes only and does not replace professional medical advice

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