Can you take Viagra with blood thinners?

Viagra, a popular treatment for erectile dysfunction (ED), is generally safe for most men but can become risky when mixed with certain medications, including blood thinners. In this blog, we will answer the question, “Can you take Viagra with blood thinners?” However, before we go into more detail regarding Viagra and blood-thinning drugs like warfarin, we will go over some basics about erectile dysfunction and Viagra.

Feel free to skip the sections you are familiar with and navigate to the topics that interest you using the table below.

What is erectile dysfunction?

Erectile dysfunction (ED) happens when a man has trouble getting or keeping an erection firm enough for sexual activity (Muneer et al., 2014). Unfortunately, more and more men around the world are experiencing erectile dysfunction, which affects their health and quality of life in many ways. It’s predicted that this trend will continue, with an estimated 322 million men possibly facing ED in the future (Ayta et al., 1999).

Having trouble with an erection once in a while isn’t usually a big deal; everyone can have an “off day.” However, when erectile dysfunction sticks around for six months or more, it’s considered chronic erectile dysfunction. Some chronic health conditions—like heart disease, high cholesterol, high blood pressure (Orimoloye et al., 2019)  and depression—are closely linked with a higher chance of developing erectile dysfunction.

Diabetes and erectile dysfunction

Diabetes, in particular, plays a big role in causing ED (Maiorino et al., 2014). In diabetes, constantly high blood sugar levels can damage blood vessels (a condition known as endothelial dysfunction), lead to harmful byproducts, increase stress within cells, and harm nerves—all of which make it harder to achieve and maintain an erection(Guay et al., 2007).

What is Viagra?

Viagra comes in three strengths:

Most people start with the Viagra 50mg dose, then adjust to 25mg or 100mg based on any side effects and how effective the 50mg dose is at creating an erection.

Viagra or sildenafil is part of a group of medications called phosphodiesterase type 5 inhibitors, which include:

• Cialis (Tadalafil)
• Spedra (Avanafil)
• Levitra (Vardenafil)

These drugs work by relaxing blood vessels in the penis, which increases blood flow and helps achieve an erection when you’re sexually aroused.

How does Viagra work?

Sildenafil, also known as Viagra, helps men with erectile dysfunction (ED) by increasing blood flow to the penis, making it easier to get and keep an erection. It’s part of a drug group called PDE5 inhibitors, which work by boosting a chemical in the body called cGMP (Corbin et al., 2004). Think of cGMP as a signal that opens “floodgates” for blood flow to the penis. When cGMP levels rise, more blood can flow in, which increases pressure and leads to an erection (Anderson et al., 2018).

Sildenafil works by blocking an enzyme called PDE5, which usually reduces cGMP levels. By stopping PDE5, sildenafil keeps cGMP levels high, allowing blood to flow more freely. However, it still only works with sexual arousal, as it’s designed to enhance the natural process.

What are blood thinners?

Blood thinners or anticoagulants are medications that prevent blood clots from forming in the bloodstream, reducing the risk of heart attacks, strokes, and related conditions.

Blood clots are natural for stopping external bleeding, but internal clots can obstruct blood flow, increasing the risk of heart attacks, strokes, and other serious complications.

Despite the term “blood thinners,” these medications don’t actually make the blood thinner; they slow down the clotting process. This means that when an injury occurs, it might take longer for the bleeding to stop, which is why bleeding is a possible side effect of anticoagulant use.

Anticoagulants are divided into several types, each suited for different conditions: antiplatelets (such as Aspirin) for those at risk of heart attacks, oral anticoagulants like warfarin for conditions like atrial fibrillation, and heparin for emergency situations, often administered by injection (InformedHealth.org, 2022).

The types of blood thinners

Antithrombotic drugs, like antiplatelets and anticoagulants, are widely prescribed to prevent and treat heart and blood vessel issues. These include medications like clopidogrel, which stops platelets from clumping, and warfarin, which prevents blood from clotting too quickly. While both reduce the risk of dangerous blood clots, they can increase the risk of bleeding and have limitations, such as different effects on people due to metabolism, other medications, and genetics.

Newer drugs have been developed to work faster, with fewer interactions and more consistent results across different patients. These newer antiplatelet options include prasugrel and ticagrelor, while newer anticoagulants include dabigatran, rivaroxaban, apixaban, and edoxaban (Mega et al, 2015).

Two main types of blood thinners are:

• Anticoagulants, like warfarin and heparin, reduce the body’s clotting ability.
• Antiplatelets, like aspirin and clopidogrel, stop blood cells (platelets) from sticking together.

Blood thinners are essential for people with heart or blood vessel disease or those with an irregular heartbeat (arrhythmia), as they help keep blood flowing smoothly and prevent blockages.

However, taking Viagra while on blood thinners can lead to complications. In this article, we’ll explore why combining these medications can be risky.

What are platelets?

Platelets are small, disc-shaped cell fragments in your blood that play a crucial role in clotting. When you get a cut or injury, platelets rush to the area and stick together to form a plug, helping to stop the bleeding. They also release chemicals that attract even more platelets to the site, eventually forming a clot to seal the wound. Although platelets are only part of the body’s clotting system, they’re essential for stopping bleeding and beginning the healing process (Periayah et al, 2017).

Is Viagra a blood thinner?

While Viagra and other PDE5 inhibitors, such as tadalafil, are not classed as blood thinners. PDE5 inhibitors primarily improve blood flow to the penis by relaxing the blood vessels and blocking the enzyme PDE5. This lets blood flow more freely to the area, making it easier to get and maintain an erection. While Viagra’s effect on blood flow can lower blood pressure temporarily, it doesn’t have the same clot-preventing effects as blood thinners.

However, PDE5 inhibitors (PDE5Is) might influence bleeding because they can act directly on platelets, which have PDE5 enzymes in them. Sildenafil reduces how well platelets (tiny blood cells that help to clotting) stick together in lab settings, and this effect can increase when combined with nitrates. (Berkels et al, 2001).

Studies have shown that taking Viagra 100 mg of sildenafil slightly extended bleeding time for about an hour after taking it, while a Viagra 50 mg dose did not affect bleeding time  (Berkels et al., 2001).

Nosebleeds have been linked to the on-demand use of sildenafil and tadalafil for erectile dysfunction (Ismail et al., 2005)

Can you take Viagra with blood thinners?

The above evidence demonstrates that PDE5 inhibitors (PDE5Is) like sildenafil (Viagra) may have a slight impact on bleeding. This could potentially cause issues with men who are already taking blood-thinning medications or those with certain health conditions.

Unfortunately, the use of PDE5 inhibitors, such as Viagra, in erectile dysfunction has not been widely used in patients with bleeding disorders or those with active ulcers. However, in some studies, sildenafil raised the chance of nosebleeds in patients taking vitamin K antagonists from 2% to 9% (Schwartz et al., 2010).

While the overall effect on bleeding time is minimal, caution is advised when PDE5Is are combined with other blood-thinning agents, such as vitamin K antagonists like warfarin, aspirin, or nitrates.

For example, combining sildenafil with nitrates or heparin may increase bleeding risks. No studies have yet evaluated interactions between PDE5Is and medications like dipyridamole, ticlopidine, or clopidogrel, but theoretically, these combinations could enhance bleeding risks.

So, the take-home advice is that it is not recommended to take Viagra, sildenafil, or any other PDE5 inhibitors like tadalafil or vardenafil if you are already taking blood thinners or nitrates.

The only time when it is suitable to take Viagra is if you are under the supervision of a doctor who is monitoring your clotting times, then there isn’t usually a problem.

What are the side effects of Viagra?

Along with headaches, several other side effects can occur with Viagra use. The most commonly reported side effects include:

• Flushing (30.8%)
• Headache (25.4%)
• Nasal congestion (18.7%)
• Heartburn (10.5%)

These side effects are generally mild and short-lasting  (Anderson et al., 2018).

Who should not take Viagra?

Viagra is widely used to treat erectile dysfunction (ED) and is generally effective for most men. However, men with some health conditions should exercise extra caution when using it. For instance, individuals with heart failure, a recent heart attack or stroke (within the past six months), or unstable chest pain (angina) should not use Viagra.

 It should never be combined with nitrate medications like nitroglycerin, as this can cause dangerous effects.

For those with specific heart issues, such as uncontrolled high blood pressure, Viagra may not be the safest option (Lim et al., 2002).

Sildenafil (Viagra) contraindications and precautions

If you are thinking of using Viagra for erectile dysfunction, have a quick look at the following list to see if any of the following apply (NHS UK)

• Allergic Reaction: If you’ve ever had an allergic reaction to sildenafil or any other medication.
• Nitrate Use: Taking nitrates for chest pain (angina) as it can cause a severe drop in blood pressure.
• Heart or Liver Problems: Serious heart or liver conditions may make sildenafil unsafe.
• Recent Heart Issues: A recent history of stroke, heart attack, or heart problems, as the physical exertion of sex may place additional strain on your heart.
• Low Blood Pressure: Not recommended if you have low blood pressure (hypotension).
• Inherited Eye Disease: Conditions like retinitis pigmentosa.
• Blood Disorders: Sickle cell anaemia, leukaemia (blood cell cancer), or multiple myeloma (bone marrow cancer).
• Penile Deformity: Conditions like Peyronie’s disease (curved penis) or other deformities.
• Stomach Ulcer: Existing stomach ulcers may increase bleeding risk.
• Bleeding Disorders: Issues like haemophilia that affect blood clotting.

For more information on Sildenafil (Viagra), consult a healthcare professional.

To determine if Viagra or sildenafil is right for you, consider completing our quick erectile dysfunction health questionnaire.

Combining Viagra with other substances

1. Grapefruit: Grapefruit juice can intensify Viagra’s effects by increasing its bioavailability in the bloodstream and delaying its absorption. This can potentially increase the side effects like headaches or low blood pressure. Although it’s not usually harmful to have grapefruit juice with sildenafil, avoiding this combination is generally a good idea (Jetter et al., 2002).
2. High-fat meals: Eating a high-fat meal can slow down how quickly sildenafil is absorbed, extending the time to reach peak levels by over an hour and reducing peak concentration by about 29% (Nichols et al., 2002). So, to make sure your night of passion goes smoothly, It’s best to stick with lighter meals when planning to take Viagra.
3. Alcohol: While a small amount of alcohol is usually safe, consuming it in large amounts can worsen Viagra’s side effects and make it harder to get an erection. Alcohol can also increase your risk of side effects like flushing or dizziness. To learn more about the effects of combining Viagra with alcohol, read our blog, “Can I drink alcohol while taking sildenafil?”

Key Viagra takeaways

• Viagra isn’t a blood thinner and works by increasing blood flow to the penis, not by preventing clots.
• Blood thinners and Viagra can sometimes be taken together, but only under medical supervision.
• Watch out for foods and medications that could interact with Viagra, such as grapefruit, fatty foods, alcohol, and certain blood pressure meds.
• Side effects are usually mild but can be severe in rare cases, so contact a doctor if you notice anything unusual.

Want to know more about Viagra and other erectile dysfunction treatments?

If you are curious to know more about Viagra, we have written several informative blog articles, including the following:

• Understanding Viagra headaches: causes and solutions
• Why does Viagra cause heartburn?
• Can Viagra cause blood clots?
• Can Viagra cause a stroke?
• Does Viagra make you last longer?
• Can I drink alcohol while taking sildenafil?
• Can Viagra make you bigger?
• How often can you take Viagra? A guide for safe use and effectiveness
• How long does sildenafil last for?

Getting support for erectile dysfunction

You should not feel shy talking about erectile dysfunction; as we mentioned previously, think of it as the canary in the mineshaft, warning you that something is wrong with your blood vessels. It may even be that your blood vessels are fine, and it could be a psychological problem.

 Whatever the cause, the team at Medical Mojo are here to help. We can guide you on the correct treatment, advise you on what to do when the PDE5 inhibitors don’t work, and even help you design a completely personalised solution. However, the first step is reaching out to us. So, if you have any questions, please don’t hesitate to contact us.

Why choose Medical Mojo for sexual health support?

If you’re considering sildenafil or looking for other ways to tackle erectile dysfunction, the treatment selected must be appropriate for you. Our healthcare questionnaires will ensure that the treatment is safe for you, but if you want to learn more or need further guidance, please do not hesitate to contact us.

Medical Mojo offers private, supportive telehealth services for men facing sensitive issues like erectile dysfunction. Their team of knowledgeable pharmacists, doctors, and therapists provide guidance on sildenafil and other options, helping you make informed, confident choices.

Benefits of choosing Medical Mojo for erectile dysfunction treatments and sexual health support

• Private, non-judgemental consultations from the comfort of your home
• Personalised recommendations based on your complete health profile
• Health screenings to confirm if Viagra is the proper treatment for you
• Ongoing support and follow-up while using Viagra
• Clear guidance on what to realistically expect from Viagra
• Holistic advice on lifestyle changes to support sexual health
• An ethos on basing all treatments and support on the latest evidence-based medicine

With Medicalmojo.co.uk, you’ll gain a realistic understanding of what Viagra can and cannot do to help with erectile dysfunction and your overall sexual health. This helps you to set healthy expectations and make well-informed treatment decisions. For more information, please contact us.

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

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