Vardenafil and Terbinafine: Can You Take Them Together?

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Vardenafil and Terbinafine: Understanding the Interaction

Published: 4 November 2026

If you're taking terbinafine for a fungal infection and considering vardenafil for erectile dysfunction, you may wonder whether vardenafil and terbinafine can be used together safely. The good news is that no major interaction is commonly reported between these two medicines, but your prescriber will still review your full medication list during the consultation to ensure the combination is appropriate for you. This page explains what each medicine does, how they work in the body, and the practical steps to use them safely.

What Is Vardenafil and How Does It Work?

Vardenafil is a prescription medicine used to treat erectile dysfunction (ED) in adult 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 increased blood flow when you are sexually aroused. This helps you achieve and maintain an erection suitable for sexual activity [5].

Vardenafil is available in 5mg, 10mg, and 20mg tablets. The usual starting dose is 10mg, taken about 25 to 60 minutes before sexual activity. You should take it no more than once a day. Vardenafil requires sexual stimulation to work—it will not cause an erection on its own. The medicine is broken down in the liver by enzymes, particularly one called CYP3A4, which is important when considering interactions with other medicines [5].

At Cured Pharmacy, vardenafil is available after a consultation with a UK-registered prescriber, who will check your medical history and current medicines to ensure it is safe and suitable for you.

What Is Terbinafine and What Is It Used For?

Terbinafine is an antifungal medicine used to treat fungal infections of the skin and nails, such as athlete's foot, ringworm, and fungal nail infections (onychomycosis). It works by stopping the growth of fungi, helping to clear the infection over time. Terbinafine is available as tablets (for more serious or widespread infections) and as creams or gels (for localised skin infections).

When taken as tablets, terbinafine is usually prescribed for several weeks or months, depending on the type and severity of the infection. Nail infections, for example, often require treatment for 6 weeks (fingernails) to 12 weeks (toenails). The medicine is absorbed into the bloodstream and reaches the affected areas, including the nails and skin.

Terbinafine tablets are broken down in the liver, but they do not significantly affect the CYP3A4 enzyme that processes vardenafil. This is one reason why terbinafine is not expected to interfere with the way vardenafil works in the body.

Do Vardenafil and Terbinafine Interact?

No major interaction between vardenafil and terbinafine is commonly reported in clinical practice or drug interaction databases. Terbinafine does not significantly inhibit or induce the CYP3A4 enzyme that breaks down vardenafil, so it is unlikely to raise or lower vardenafil levels in the blood. This means that taking terbinafine should not make vardenafil more or less effective, nor should it increase the risk of side effects from vardenafil.

However, it is important to remember that every person's situation is different. Your prescriber or pharmacist will review all your current medicines—including terbinafine—during your online consultation to check for any potential issues specific to you. This includes considering your overall health, other conditions you may have, and any other medicines you are taking alongside vardenafil and terbinafine.

You should always declare every medicine you are taking, including over-the-counter products, herbal remedies, and supplements. Never stop or change a prescribed medicine without speaking to your doctor or pharmacist first.

How the Combination Is Assessed

During your consultation at Cured Pharmacy, the prescriber will ask about your current medicines, including terbinafine, to ensure there are no contraindications or interactions. They will also check that vardenafil is safe for you based on your medical history, such as any heart conditions, blood pressure issues, or other health concerns. This careful review helps to ensure that the combination of vardenafil and terbinafine is appropriate and that you can use both medicines safely.

What Your Prescriber Checks Before Approving Vardenafil

Before prescribing vardenafil, your prescriber will review your full medical history and current medicines to ensure the treatment is safe for you. They will check for any conditions that make vardenafil unsuitable, such as recent heart attack or stroke, unstable angina, severe heart failure, very low blood pressure, or a history of sudden vision loss (non-arteritic anterior ischaemic optic neuropathy, or NAION) [5].

Certain medicines must never be taken with vardenafil because they can cause a dangerous drop in blood pressure. These include nitrates (such as GTN spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, and recreational drugs called 'poppers' (amyl or alkyl nitrites). You must not take vardenafil if you are using any of these. You should also not take vardenafil alongside another PDE5 inhibitor, such as sildenafil or tadalafil [5].

If you take alpha-blockers (such as doxazosin or tamsulosin) for prostate problems or high blood pressure, your prescriber will ensure you are stable on that medicine and may start you on a lower dose of vardenafil to reduce the risk of dizziness or low blood pressure. Medicines that strongly inhibit the CYP3A4 enzyme—such as ritonavir, ketoconazole, itraconazole, or clarithromycin—can raise vardenafil levels, and vardenafil is often avoided or contraindicated with these medicines [5]. Your prescriber will check the summary of product characteristics (SmPC) if you are taking any of these.

Declaring All Your Medicines

It is essential to list every medicine you are taking during your consultation, including prescription medicines like terbinafine, over-the-counter products, herbal remedies (such as St John's wort), and supplements. This allows the prescriber to identify any potential interactions and adjust your treatment plan if needed. Being open and thorough helps to keep you safe.

Practical Advice for Taking Vardenafil and Terbinafine Together

If your prescriber has approved vardenafil and you are also taking terbinafine, you can usually take both medicines as directed without special timing adjustments. Vardenafil is taken about 25 to 60 minutes before sexual activity, and terbinafine tablets are usually taken once a day, often with or after food. There is no need to separate the doses, but follow the instructions given by your prescriber and on the medicine labels.

Be aware of the common side effects of each medicine. Vardenafil can cause headache, flushing, indigestion, nasal congestion, or dizziness. Terbinafine may cause stomach upset, loss of appetite, headache, or skin rash. If you experience any new or worsening symptoms after starting either medicine, speak to your pharmacist or doctor.

Avoid drinking large amounts of alcohol when taking vardenafil, as alcohol can worsen erectile dysfunction and increase the risk of dizziness or low blood pressure. Grapefruit juice can raise the levels of vardenafil in your blood, so it is best to avoid it. If you develop any warning signs—such as an erection lasting more than four hours, sudden loss of vision or hearing, or chest pain during sex—seek urgent medical help.

When to Seek Further Advice About Vardenafil and Terbinafine

If you have any concerns about taking vardenafil and terbinafine together, or if you experience side effects that worry you, contact your pharmacist or doctor for advice. Do not stop taking terbinafine without consulting your doctor, as stopping an antifungal treatment early can allow the infection to return or worsen. Similarly, if vardenafil is not working as expected or you have questions about your dose, speak to the prescriber who issued your prescription.

If you are prescribed a new medicine while taking vardenafil and terbinafine, let the prescriber know about both medicines so they can check for interactions. This is especially important if you are started on a medicine that affects the liver enzymes (such as certain antibiotics, antifungals other than terbinafine, or HIV medicines), as these could potentially interact with vardenafil.

Remember that erectile dysfunction can sometimes be an early sign of underlying health conditions, such as heart disease or diabetes [1]. If you are experiencing ED for the first time, it is a good idea to see your GP for a full health check, even if you are also seeking treatment through an online pharmacy. Your GP can investigate any underlying causes and provide holistic care.

Support from Cured Pharmacy

At Cured Pharmacy, our team is here to support you throughout your treatment. If you have questions about your medicines or need advice, you can contact our pharmacists for guidance. We are committed to providing safe, effective, and confidential care for all our patients.

Scientific References

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