Vardenafil and Abiraterone: Can They Be Taken Together?

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Vardenafil and Abiraterone: Understanding the Interaction

Published: 27 October 2026

If you're taking abiraterone for prostate cancer and considering vardenafil for erectile dysfunction, it's important to understand how these medicines interact. Vardenafil and abiraterone can be taken together, but only under careful medical supervision because abiraterone may increase vardenafil levels in your body, raising the risk of side effects. This page explains the interaction in plain English, what your prescriber will check, and practical steps to use vardenafil safely alongside cancer treatment.

What Is Vardenafil and How Does It Work?

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

Vardenafil is usually taken about 25 to 60 minutes before sex, and it works only when you are sexually stimulated—it does not cause an automatic erection. The usual starting dose is 10 mg, which can be adjusted to 5 mg or 20 mg depending on how well it works and whether you experience side effects. You should take vardenafil no more than once a day [5].

Common side effects include headache, flushing, indigestion, and nasal congestion. More serious but rare side effects include sudden vision or hearing loss, chest pain during sex, or an erection lasting more than four hours (priapism), which requires urgent medical attention. Vardenafil is not suitable for everyone, particularly men taking nitrates for chest pain or those with severe heart or liver problems [5].

What Is Abiraterone and Why Is It Prescribed?

Abiraterone is a prescription medicine used to treat prostate cancer, particularly advanced or metastatic disease. It works by blocking the production of androgens (male hormones such as testosterone) throughout the body, including in the prostate gland, adrenal glands, and tumour tissue. Because prostate cancer cells often rely on androgens to grow, reducing these hormones can slow or stop the cancer's progression [12].

Abiraterone is usually taken as a once-daily tablet (typically 1,000 mg) on an empty stomach, at least one hour before or two hours after food. It is almost always prescribed alongside a corticosteroid such as prednisolone or prednisone to reduce side effects. Common side effects include fluid retention, low potassium levels, high blood pressure, fatigue, and liver enzyme changes. Your doctor will monitor your blood pressure, liver function, and potassium levels regularly while you are on abiraterone [12].

Erectile dysfunction is a recognised side effect of prostate cancer treatment, including hormone therapy like abiraterone. Many men undergoing treatment for prostate cancer experience ED, and it is entirely reasonable to seek treatment for this. However, because abiraterone affects how the body processes other medicines, any ED treatment must be carefully chosen and monitored by your prescriber [12].

How Do Vardenafil and Abiraterone Interact?

Vardenafil and abiraterone interact because abiraterone inhibits an enzyme in the liver called CYP3A4, which is responsible for breaking down vardenafil. When CYP3A4 is blocked or slowed, vardenafil stays in your bloodstream for longer and at higher levels than usual. This means the effects of vardenafil—both the intended benefits and the potential side effects—may be stronger or last longer [5][12].

Higher levels of vardenafil can increase the risk of side effects such as headache, dizziness, flushing, visual disturbances, and a dangerous drop in blood pressure, particularly if you are also taking other medicines that lower blood pressure. For this reason, the combination of vardenafil and abiraterone requires careful dose adjustment and close monitoring by your prescriber. In many cases, your doctor will start you on the lowest dose of vardenafil (5 mg) and monitor your response [5].

It is essential that you tell your prescriber about all medicines you are taking, including abiraterone, before starting vardenafil. Your prescriber will review your full medication list, check for other interactions, and decide whether vardenafil is suitable or whether an alternative PDE5 inhibitor with a different interaction profile might be safer. Never adjust the dose of either medicine yourself, and do not take vardenafil if it has not been prescribed for you while you are on abiraterone [5][12].

Why CYP3A4 Inhibition Matters

CYP3A4 is one of the most important enzymes in the liver for metabolising medicines. Many commonly prescribed drugs are broken down by CYP3A4, so when a medicine like abiraterone inhibits this enzyme, it can affect the levels of other medicines in your system. This is not unique to vardenafil—other PDE5 inhibitors, including sildenafil and tadalafil, are also metabolised by CYP3A4, though the degree of interaction varies [3][4][5].

Understanding this interaction helps explain why your prescriber may choose one ED medicine over another, or why they start you on a lower dose. It also highlights the importance of declaring every medicine, supplement, and herbal product you take during your consultation, as even over-the-counter products like St John's wort can affect CYP3A4 activity [5].

What Will Your Prescriber Check Before Prescribing Vardenafil?

Before prescribing vardenafil to someone taking abiraterone, your prescriber will carry out a thorough clinical assessment. This includes reviewing your full medical history, current medicines (including abiraterone and any corticosteroids), blood pressure, heart health, and liver function. Because abiraterone can raise blood pressure and affect liver enzymes, and vardenafil can lower blood pressure, your prescriber needs to ensure the combination is safe for you [5][12].

Your prescriber will ask about any history of heart disease, stroke, low blood pressure, liver or kidney problems, bleeding disorders, stomach ulcers, and eye conditions such as non-arteritic anterior ischaemic optic neuropathy (NAION). They will also check whether you are taking any medicines that are absolutely contraindicated with vardenafil, such as nitrates (GTN spray, isosorbide mononitrate), nicorandil, riociguat, or recreational drugs known as 'poppers' (amyl or alkyl nitrites). If you are taking any of these, you cannot take vardenafil [5].

If you are on alpha-blockers for urinary symptoms (such as tamsulosin or doxazosin), your prescriber will be particularly cautious, as the combination with vardenafil can cause a significant drop in blood pressure and dizziness. You should be stable on the alpha-blocker before starting vardenafil, and the lowest dose of vardenafil will be used initially. Your prescriber may also consider whether an alternative PDE5 inhibitor, such as tadalafil, might be more suitable given your overall medication profile [5].

Monitoring and Follow-Up

Once vardenafil is prescribed, your prescriber may arrange follow-up to check how you are tolerating the medicine, whether it is effective, and whether any dose adjustment is needed. If you experience side effects such as severe headache, dizziness, visual changes, or chest pain, contact your prescriber or GP promptly. Do not simply stop taking vardenafil without advice, and never increase the dose on your own [5].

Because abiraterone requires regular blood tests to monitor liver function, potassium, and blood pressure, your oncology team will continue these checks. Make sure your GP and oncologist are aware that you are taking vardenafil, so they can coordinate your care and watch for any changes that might affect either treatment [12].

Practical Advice for Taking Vardenafil with Abiraterone

If your prescriber has approved vardenafil while you are on abiraterone, follow their instructions carefully. Take vardenafil exactly as prescribed—usually 25 to 60 minutes before sexual activity, and no more than once in 24 hours. Swallow the tablet whole with water; you can take it with or without food, though a heavy or high-fat meal may delay how quickly it works [5].

Avoid drinking grapefruit juice while taking vardenafil, as it can further increase vardenafil levels in your blood and raise the risk of side effects. Limit alcohol intake, as heavy drinking can worsen erectile dysfunction and add to the blood-pressure-lowering effect of vardenafil, increasing the risk of dizziness or fainting. If you feel dizzy or lightheaded after taking vardenafil, sit or lie down until the feeling passes, and avoid driving or operating machinery [5].

Keep all your medicines in their original packaging, store them safely away from children, and check the expiry date before use. If you miss a dose of abiraterone, take it as soon as you remember unless it is nearly time for your next dose—do not take a double dose. Vardenafil is taken only when needed, so there is no concept of a 'missed dose' for this medicine. Always carry an up-to-date list of all your medicines, including doses, and show it to any healthcare professional you see [5][12].

Alternative ED Treatments and When to Seek Help

If vardenafil is not suitable for you, or if you prefer an alternative, other PDE5 inhibitors may be considered. Sildenafil (generic Viagra) and tadalafil (generic Cialis) are also metabolised by CYP3A4, so similar precautions and dose adjustments apply when taken with abiraterone. Tadalafil has a longer duration of action (up to 36 hours) and is available as a lower-dose daily tablet, which some men find more convenient. Your prescriber will discuss which option best fits your lifestyle and medical needs [3][4].

If oral ED medicines are not effective or suitable, other treatments are available. Alprostadil is a prescription medicine that can be applied as a cream (Vitaros) to the tip of the penis or injected into the side of the penis (Caverject). Vacuum erection devices and penile implants are non-drug options that may be considered in specialist settings. Your GP or a specialist in sexual medicine or urology can provide further guidance [7].

Erectile dysfunction can be an early warning sign of cardiovascular disease or diabetes, so if you have not already done so, see your GP for a full health check. This is particularly important if you are undergoing cancer treatment, as managing your overall health can improve your quality of life and treatment outcomes. If you experience chest pain during sex, an erection lasting more than four hours, or sudden loss of vision or hearing, seek urgent medical help immediately [1][2].

Online Consultation at Cured Pharmacy

Cured Pharmacy offers a confidential online consultation service for erectile dysfunction treatments. After you complete a health questionnaire, a UK-registered prescriber will review your answers, including all current medicines such as abiraterone, and decide whether vardenafil or another PDE5 inhibitor is safe and appropriate for you. If approved, your medicine is dispensed by our GPhC-registered pharmacy and delivered discreetly to your door.

Our service is designed to be convenient and supportive, but it is not a replacement for your ongoing cancer care. Always keep your GP and oncology team informed about any new medicines you start, and attend all scheduled appointments and blood tests. If you have any questions or concerns, our pharmacist-led team is here to help.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 27 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 27 October 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 27 October 2026]
4. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 27 October 2026]
5. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 27 October 2026]
6. Joint Formulary Committee. (n.d.). Alprostadil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/alprostadil/ [accessed 27 October 2026]
7. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 27 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.

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