Vardenafil and Tolterodine: Can They Be Taken Together?

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Vardenafil and Tolterodine: Understanding the Interaction

Published: 5 November 2026

Many men wonder whether vardenafil and tolterodine can be taken together safely. The good news is that no major interaction is commonly reported between vardenafil (a medicine for erectile dysfunction) and tolterodine (used to treat overactive bladder), but both medicines can affect your heart rhythm and blood pressure, so your prescriber will carefully review your full medical history and all current medicines before approving this combination. This page explains what each medicine does, how they may interact, and what practical steps you can take to use them safely.

What is vardenafil and tolterodine used for?

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 work by relaxing blood vessels in the penis, allowing more blood to flow in when you are sexually aroused. Vardenafil is the generic version of Levitra and is usually taken about 25 to 60 minutes before sexual activity, with effects lasting for several hours. It is available in 5mg, 10mg, and 20mg tablets, and you should not take it more than once a day [5].

Tolterodine is a prescription medicine used to treat symptoms of an overactive bladder, such as a sudden urge to urinate, frequent trips to the toilet, or leaking urine. It works by relaxing the muscles in the bladder, reducing the urge to urinate. Tolterodine is usually taken once or twice a day as a regular treatment, and it belongs to a class of medicines called antimuscarinics (or anticholinergics). Many men, particularly as they get older, may need treatment for both erectile dysfunction and overactive bladder symptoms, so it is not uncommon for these two medicines to be prescribed together [12].

Can vardenafil and tolterodine be taken together?

There is no major documented interaction that prevents vardenafil and tolterodine from being used together, and many men take both medicines without problems. However, both medicines can have effects on your heart rhythm (a condition called QT prolongation) and can also lower blood pressure slightly, so your prescriber will need to check your medical history carefully before approving the combination. If you have a history of heart rhythm problems, low blood pressure, or certain other heart conditions, your prescriber may decide that the combination is not suitable for you, or they may recommend a lower dose of one or both medicines [5][12].

It is important to tell your prescriber and pharmacist about every medicine you take, including prescription medicines, over-the-counter treatments, herbal remedies, and supplements. During your online consultation at Cured Pharmacy, the prescriber will review your full medication list and medical history to ensure that vardenafil is safe for you. Never start, stop, or change the dose of any medicine without speaking to a healthcare professional first.

How the interaction works

Both vardenafil and tolterodine can, in rare cases, prolong the QT interval on an ECG (electrocardiogram), which is a measure of the electrical activity of your heart. A prolonged QT interval can increase the risk of a serious irregular heartbeat. The risk is generally low when either medicine is used alone at normal doses, but when two medicines that both affect the QT interval are used together, the risk may be slightly higher. Your prescriber will consider your individual risk factors, such as age, other medicines, and any history of heart problems, before deciding whether the combination is appropriate for you [5][12].

What your prescriber checks before approving vardenafil and tolterodine

Before prescribing vardenafil to someone already taking tolterodine, your prescriber will ask detailed questions about your medical history and current health. They will check whether you have any heart conditions (such as a recent heart attack, unstable angina, severe heart failure, or a history of abnormal heart rhythms), whether your blood pressure is very low or very high, and whether you have any other conditions that might make vardenafil unsuitable. They will also review all your current medicines to check for other interactions, particularly with medicines that are absolutely contraindicated with vardenafil, such as nitrates (GTN spray, isosorbide mononitrate), nicorandil, riociguat, or recreational drugs called poppers [5].

If you are taking other medicines that can affect your heart rhythm or blood pressure (for example, certain antibiotics, antifungals, antidepressants, or medicines for irregular heartbeats), your prescriber will assess whether the combination is safe or whether a different ED treatment might be more suitable. They may also recommend starting on a lower dose of vardenafil to minimise any risk. It is essential to answer all the questions in your consultation honestly and completely, even if you feel embarrassed, because this information is needed to keep you safe [5][12].

Practical advice for taking vardenafil and tolterodine together

If your prescriber approves the combination of vardenafil and tolterodine, there are some practical steps you can take to use both medicines safely. Take each medicine exactly as prescribed: tolterodine is usually taken once or twice a day at regular times, while vardenafil is taken only when you plan to have sexual activity, about 25 to 60 minutes beforehand. Do not take vardenafil more than once in 24 hours, even if the first dose did not work as well as you hoped. Vardenafil needs sexual stimulation to work, so it will not cause an erection on its own [5].

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, leading to dizziness or fainting. Grapefruit juice can also increase the levels of vardenafil in your blood, so it is best to avoid it. If you experience dizziness, lightheadedness, or fainting after taking vardenafil, sit or lie down until you feel better, and let your prescriber know at your next review. If you develop any new symptoms, such as palpitations (a fast or irregular heartbeat), chest pain, or shortness of breath, seek medical advice promptly [5][12].

What to do if you miss a dose

Tolterodine is a regular daily medicine, so if you miss a dose, take it as soon as you remember unless it is nearly time for your next dose. In that case, skip the missed dose and take your next dose at the usual time. Do not take a double dose to make up for a forgotten one. Vardenafil is taken only when needed, so there is no concept of a 'missed dose'—simply take it about 25 to 60 minutes before you plan to have sex, and do not take more than one dose in 24 hours [5][12].

Warning signs and when to seek help with vardenafil and tolterodine

Most men who take vardenafil and tolterodine together do not experience serious problems, but it is important to know the warning signs that need urgent medical attention. If you develop an erection that lasts longer than four hours (a condition called priapism), go to A&E immediately or call 999, as this can cause permanent damage to the penis if not treated quickly. Sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing (sometimes with ringing in the ears or dizziness), are rare but serious side effects of PDE5 inhibitors and require urgent medical help [5].

If you experience chest pain, severe dizziness, or fainting during or after sex, stop sexual activity and seek medical help straight away. These symptoms could indicate a problem with your heart or blood pressure. If you notice a fast, slow, or irregular heartbeat (palpitations), or if you feel unusually short of breath or develop swelling in your legs, contact your GP or call NHS 111 for advice. Always keep your prescriber informed of any new symptoms or side effects, and attend any follow-up appointments or reviews that are recommended [5][12].

Other medicines and lifestyle factors that affect vardenafil and tolterodine

In addition to tolterodine, there are many other medicines that can interact with vardenafil. Never take vardenafil with nitrates (such as GTN spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, or recreational drugs called poppers (amyl or alkyl nitrites), as the combination can cause a dangerous drop in blood pressure. Do not take vardenafil with another PDE5 inhibitor (such as sildenafil, tadalafil, or avanafil) at the same time [5].

If you take medicines for high blood pressure or an enlarged prostate (alpha-blockers such as doxazosin, tamsulosin, or alfuzosin), tell your prescriber, as these can add to the blood-pressure-lowering effect of vardenafil and may cause dizziness. Certain antibiotics (such as clarithromycin or erythromycin), antifungals (such as ketoconazole or itraconazole), and HIV medicines (such as ritonavir or cobicistat) can increase the levels of vardenafil in your blood, so your prescriber may need to adjust your dose or choose a different ED treatment. St John's wort (a herbal remedy for low mood) can make vardenafil less effective [5].

Lifestyle factors also matter: smoking, heavy alcohol use, lack of exercise, and being overweight can all make erectile dysfunction worse. Eating a healthy diet, staying active, cutting down on alcohol, and stopping smoking can improve your erections and your overall health. If you have not already done so, see your GP for a general health check, as erectile dysfunction can be an early warning sign of heart disease or diabetes [1][2].

Tolterodine and other medicines

Tolterodine can also interact with other medicines. It should be used with caution if you take other medicines that affect the QT interval (such as certain antibiotics, antipsychotics, or medicines for irregular heartbeats) or medicines that are broken down by the same liver enzymes (CYP3A4 or CYP2D6). Your prescriber will review all your medicines during your consultation to check for interactions. If you are prescribed a new medicine by your GP or another doctor, always tell them that you are taking tolterodine and vardenafil [12].

Scientific References

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