Vardenafil and Flecainide: Can They Be Taken Together?

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Vardenafil and Flecainide: Understanding the Interaction

Published: 30 October 2026

Many men taking flecainide for heart rhythm problems wonder whether vardenafil and flecainide can be taken together safely. The good news is that there is no direct, dangerous interaction between these two medicines, but your prescriber will need to check your heart health carefully before prescribing vardenafil. Because flecainide is used to control irregular heartbeats, it's essential that your cardiovascular system is stable enough for sexual activity and that any erectile dysfunction treatment is chosen with your full medical history in mind.

What is vardenafil and how does it work?

Vardenafil (also known by the brand name Levitra) is a prescription medicine used to treat erectile dysfunction in men [5]. It belongs to a group of medicines called PDE5 inhibitors, which work by relaxing the blood vessels in the penis, allowing more blood to flow in when you are sexually aroused. This increased blood flow helps you get and keep an erection suitable for sexual activity.

Vardenafil is usually taken about 25 to 60 minutes before sexual activity, and its effects can last for several hours [5]. It comes in 5mg, 10mg, and 20mg tablets, and the dose your prescriber recommends will depend on your individual needs and medical history. It's important to remember that vardenafil will only work when you are sexually stimulated – it does not cause an automatic erection.

Like all PDE5 inhibitors, vardenafil can lower blood pressure slightly, which is why it must not be taken with certain medicines (such as nitrates) and why your prescriber will check your heart health before prescribing it [5].

What is flecainide and why is it prescribed?

Flecainide is a prescription medicine used to control abnormal heart rhythms (arrhythmias), particularly atrial fibrillation and other types of irregular heartbeat. It works by slowing down the electrical signals in the heart, helping it to beat in a regular, steady rhythm. Flecainide is usually prescribed by a cardiologist or GP after careful assessment of your heart condition.

Because flecainide affects the electrical activity of the heart, it is important that anyone taking it is monitored regularly. Your doctor will check your heart rhythm with an ECG (electrocardiogram) before starting treatment and at intervals during treatment. Flecainide can sometimes cause side effects such as dizziness, visual disturbances, or palpitations, and it is not suitable for everyone with heart problems.

If you are taking flecainide, it means you have a heart condition that requires ongoing management. This is why any new medicine – including treatments for erectile dysfunction – must be discussed with your prescriber, who will assess whether your heart is healthy enough for sexual activity and whether the ED treatment is safe for you.

Does flecainide cause erectile dysfunction?

Flecainide itself is not commonly reported to cause erectile dysfunction directly. However, the heart condition for which flecainide is prescribed, as well as anxiety or stress about your heart health, can contribute to ED. Cardiovascular disease is one of the most common underlying causes of erectile dysfunction, because healthy blood flow is essential for erections [1][2].

If you have noticed erectile problems since starting flecainide or since your heart condition was diagnosed, it is worth discussing this with your GP or cardiologist. They can help identify whether the ED is related to your heart health, the medicine, or other factors such as diabetes, high blood pressure, or psychological stress.

Vardenafil and flecainide: is there an interaction?

There is no direct, dangerous interaction between vardenafil and flecainide in the way that there is, for example, between vardenafil and nitrates (which must never be taken together). However, both medicines can affect your cardiovascular system, so your prescriber will need to assess your heart health carefully before prescribing vardenafil if you are taking flecainide.

Vardenafil can cause a small drop in blood pressure, and in some people this may lead to dizziness or light-headedness [5]. Flecainide, meanwhile, is used to control heart rhythm, and sexual activity itself places extra demand on the heart. Your prescriber will check that your heart condition is stable and that sexual activity is safe for you before recommending any erectile dysfunction treatment.

In practice, many men taking flecainide can use vardenafil safely, provided their heart condition is well controlled and they have been assessed by a prescriber who knows their full medical history. The key is to be open and honest about all the medicines you take and any symptoms you experience, so that your prescriber can make an informed decision about the safest and most effective treatment for you.

What will my prescriber check before prescribing vardenafil?

Before prescribing vardenafil (or any PDE5 inhibitor) to someone taking flecainide, your prescriber will carry out a thorough assessment of your cardiovascular health. They will ask about your heart condition, how well it is controlled, any symptoms you experience (such as chest pain, breathlessness, or palpitations), and whether you have had any recent heart attacks, strokes, or other serious cardiovascular events [2].

Your prescriber will also check all the other medicines you are taking, because some drugs can interact with vardenafil. For example, vardenafil must never be taken with nitrates (such as GTN spray or isosorbide mononitrate), nicorandil, riociguat, or recreational drugs called 'poppers', as these combinations can cause a dangerous drop in blood pressure. If you are taking alpha-blockers (such as tamsulosin or doxazosin) for prostate problems, your prescriber will ensure you are stable on that medicine and may start you on a lower dose of vardenafil [5].

Your prescriber will also ask about your blood pressure, any history of stroke or heart failure, and whether you have any eye problems (particularly a condition called NAION, which causes sudden vision loss). If you have severe heart failure, unstable angina, or very low blood pressure, vardenafil may not be suitable for you. The online consultation at Cured Pharmacy is reviewed by a UK-registered prescriber who will assess all these factors before approving your treatment.

Can I take other ED medicines if I'm on flecainide?

If vardenafil is not suitable for you, or if you would prefer a different option, there are other PDE5 inhibitors available, including sildenafil (Viagra), tadalafil (Cialis), and avanafil (Spedra). All of these work in a similar way to vardenafil, and the same cardiovascular checks will apply [3][4][6].

Your prescriber will help you choose the most appropriate ED treatment based on your heart condition, other medicines, and personal preferences. For example, tadalafil can be taken as a lower daily dose or as a higher on-demand dose, and its effects last much longer (up to 36 hours) than vardenafil or sildenafil. Avanafil works more quickly (in about 15 to 30 minutes) and may suit men who want a faster-acting option [6][11].

Practical advice for taking vardenafil with flecainide

If your prescriber has approved vardenafil for you, take it exactly as directed. Vardenafil is usually taken about 25 to 60 minutes before sexual activity, and you should not take more than one dose in 24 hours [5]. Swallow the tablet whole with water, and remember that it will only work if you are sexually aroused – it does not cause an automatic erection.

Avoid drinking large amounts of alcohol when taking vardenafil, as alcohol can make erectile dysfunction worse and can add to the blood-pressure-lowering effect of the medicine, increasing the risk of dizziness. Grapefruit juice can also raise the level of vardenafil in your blood, so it is best to avoid it. Take vardenafil on an empty stomach or after a light meal for the best results – a heavy, fatty meal can delay how quickly it works.

Continue to take your flecainide exactly as prescribed by your cardiologist or GP, and do not stop or change the dose without medical advice. If you experience any new symptoms after starting vardenafil – such as dizziness, chest pain, palpitations, or visual disturbances – stop taking vardenafil and contact your GP or prescriber for advice. Always keep your prescriber informed of any changes to your medicines or your health.

Warning signs and when to seek urgent help

Most men taking vardenafil and flecainide together do not experience serious problems, but it is important to know the warning signs that need urgent medical attention. If you develop chest pain or discomfort during or after sexual activity, stop what you are doing and seek medical help immediately. Do not take nitrate medicines (such as GTN spray) to relieve chest pain if you have taken vardenafil in the past 24 hours, as this combination can cause a dangerous drop in blood pressure.

If you have an erection that lasts longer than four hours (a condition called priapism), you must go to A&E straight away. Priapism is a medical emergency and, if not treated promptly, can cause permanent damage to the penis. Other warning signs that need urgent attention include sudden loss of vision in one or both eyes, sudden decrease or loss of hearing (sometimes with ringing in the ears or dizziness), or severe dizziness or fainting.

If you experience palpitations, a very fast or irregular heartbeat, severe breathlessness, or swelling of the ankles or legs, contact your GP or cardiologist urgently, as these may be signs that your heart condition needs review. Always be honest with healthcare professionals about all the medicines you are taking, including any ED treatments, so they can give you the safest and most effective care.

Can I use vardenafil if my heart condition changes?

If your heart condition changes – for example, if you have a new episode of atrial fibrillation, your flecainide dose is adjusted, or you are admitted to hospital with heart problems – you should not take vardenafil until you have been reviewed by your prescriber or cardiologist. Sexual activity and ED medicines are only safe when your heart condition is stable and well controlled [2].

Always inform your prescriber at Cured Pharmacy if there are any changes to your health or medicines. The online consultation includes questions about your cardiovascular health, and it is important to answer these honestly and update your medical history if anything changes. Your safety is the top priority, and your prescriber will only approve treatment if it is appropriate for you.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 30 October 2026]
2. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 30 October 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 30 October 2026]
4. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 30 October 2026]
5. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 30 October 2026]
6. Joint Formulary Committee. (n.d.). Avanafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/avanafil/ [accessed 30 October 2026]
7. National Institute for Health and Care Excellence. (2014). Erectile dysfunction: avanafil (ESNM45). https://www.nice.org.uk/advice/esnm45 [accessed 30 October 2026]

Information on this page is for educational purposes only and is not medical advice. Prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting or changing any medication.