Vardenafil and Capecitabine: Can They Be Taken Together?

Vardenafil and Capecitabine: Understanding the Interaction

Published: 28 October 2026

If you're taking capecitabine (a chemotherapy medicine) and considering vardenafil for erectile dysfunction, you may wonder whether vardenafil and capecitabine can be used together safely. The good news is that no major direct interaction between these two medicines is commonly reported in clinical practice. However, because capecitabine is used to treat cancer and can affect your overall health, your prescriber will carefully review your full medical history, current treatment plan, and any other medicines you take before prescribing vardenafil.

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 blood vessels in the penis, allowing increased blood flow when you are sexually aroused. This helps you achieve and maintain an erection suitable for sexual activity.

Vardenafil is typically taken about 25 to 60 minutes before sexual activity, and it requires sexual stimulation to work [5]. It comes in doses of 5mg, 10mg, and 20mg, and you should not take it more than once a day. The medicine does not cure erectile dysfunction but can help manage the symptoms effectively when used as directed. Like all PDE5 inhibitors, vardenafil is only available on prescription in the UK after a clinical assessment by a qualified prescriber.

What Is Capecitabine and Why Is It Prescribed?

Capecitabine is a chemotherapy medicine used to treat certain types of cancer, including bowel (colorectal) cancer, breast cancer, and stomach cancer. It is an oral tablet that your body converts into an active chemotherapy drug called 5-fluorouracil (5-FU). Capecitabine works by interfering with the growth and spread of cancer cells in your body.

Because capecitabine is a powerful medicine used to treat serious conditions, it can cause side effects and may interact with other medicines. Common side effects include hand-foot syndrome (redness, swelling, or pain on the palms and soles), diarrhoea, nausea, fatigue, and changes in blood cell counts. Your oncology team will monitor you closely throughout treatment and adjust your dose if needed. It's essential to tell your cancer specialist about all medicines you take, including treatments for erectile dysfunction.

How Capecitabine May Affect Your General Health

Chemotherapy can affect your overall wellbeing, energy levels, and cardiovascular health. Some men undergoing cancer treatment experience erectile dysfunction as a result of fatigue, stress, hormonal changes, or the physical effects of the disease and its treatment. If you're considering ED treatment while on capecitabine, your prescriber will assess whether you are well enough for sexual activity and whether vardenafil is appropriate given your current health status.

Do Vardenafil and Capecitabine Interact Directly?

There is no commonly reported major direct drug interaction between vardenafil and capecitabine. These medicines work through different mechanisms in the body: vardenafil affects blood flow to the penis by inhibiting an enzyme called PDE5, while capecitabine is converted into a chemotherapy agent that targets rapidly dividing cancer cells. They are not known to interfere with each other's breakdown or effectiveness in a clinically significant way.

However, this does not mean the combination is automatically safe for everyone. Your prescriber will consider your overall health, the stage and type of your cancer treatment, your cardiovascular fitness, and any other medicines you are taking. Some chemotherapy regimens can affect heart function or blood pressure, and vardenafil can also lower blood pressure slightly. Your oncology team and the prescriber reviewing your ED treatment request will work together (or you should inform both) to ensure all aspects of your care are coordinated.

What Your Prescriber Checks Before Approving Vardenafil and Capecitabine Together

When you request vardenafil through an online consultation at Cured Pharmacy, the UK-registered prescriber will ask detailed questions about your current health and all medicines you take, including capecitabine. They will check whether you are fit for sexual activity, as this can place demands on your heart and circulation. If you have been unwell due to cancer or chemotherapy side effects, or if your cardiovascular health has been affected, the prescriber may advise waiting until you are more stable or may suggest a lower starting dose.

The prescriber will also review any other medicines you take alongside capecitabine. For example, some people on chemotherapy also take anti-sickness medicines, painkillers, or blood-pressure treatments, and these can interact with vardenafil. You must declare every medicine, supplement, and herbal remedy you use. Never take vardenafil if you are also using nitrates (such as GTN spray or isosorbide mononitrate), nicorandil, riociguat, or recreational drugs called poppers, as this combination can cause a dangerous drop in blood pressure [5].

Coordinating Care Between Your Oncology Team and ED Prescriber

It is important to keep both your cancer specialist and your ED prescriber informed. If your oncology team changes your capecitabine dose, adds a new medicine, or if you experience significant side effects, let the prescriber know before taking vardenafil. Similarly, if you start ED treatment, mention it at your next oncology appointment. Good communication ensures your care is safe and joined-up.

Practical Advice for Using Vardenafil While on Capecitabine

If your prescriber approves vardenafil, start with the lowest effective dose and see how you respond. Take vardenafil about 25 to 60 minutes before planned sexual activity, and remember it only works with sexual stimulation [5]. Do not take more than one dose in 24 hours. Avoid heavy meals and excessive alcohol before taking vardenafil, as these can reduce its effectiveness and increase the risk of side effects such as dizziness or headache.

Monitor how you feel. If you experience unusual tiredness, dizziness, chest pain, or any new symptoms after taking vardenafil, stop using it and contact your GP or oncology team. If you have an erection lasting more than four hours, sudden loss of vision or hearing, or chest pain during sex, seek urgent medical help immediately. These are rare but serious side effects that require prompt attention. Keep your capecitabine and vardenafil in their original packaging, store them as directed, and never share your medicines with others.

Other Considerations: Vardenafil and Capecitabine in Context

Erectile dysfunction is common among men undergoing cancer treatment, and it can affect quality of life and emotional wellbeing. Addressing ED is a legitimate part of holistic cancer care, and many men successfully use PDE5 inhibitors like vardenafil during or after chemotherapy. However, your safety and overall health must come first. If vardenafil is not suitable for you at this time, your prescriber may suggest waiting until your treatment is complete or trying a different approach.

Alternative ED treatments include other PDE5 inhibitors such as sildenafil (Viagra) or tadalafil (Cialis), which may be considered depending on your individual circumstances and any other medicines you take. Non-oral options like alprostadil cream (Vitaros) or Eroxon gel may also be discussed. Your prescriber will tailor advice to your needs. Remember, erectile dysfunction can be an early sign of cardiovascular disease or diabetes, so if ED is new or worsening, see your GP for a full health check [1][2].

When to Seek Further Medical Advice

If your erectile dysfunction persists despite treatment, worsens, or is accompanied by other symptoms such as chest pain, shortness of breath, or severe fatigue, contact your GP or oncology team. Do not stop taking capecitabine or any prescribed medicine without medical advice. If you have concerns about side effects from either vardenafil or capecitabine, speak to a healthcare professional promptly. Your wellbeing is the priority, and open communication with your care team is essential.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 28 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 28 October 2026]
3. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 28 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.