Vardenafil and Montelukast: Can You Take Them Together?

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Vardenafil and Montelukast: Understanding the Interaction

Published: 2 November 2026

Many men wonder whether vardenafil and montelukast can be taken together safely. The good news is that no major interaction is commonly reported between vardenafil (a medicine for erectile dysfunction) and montelukast (a leukotriene receptor antagonist used for asthma and allergies). However, your prescriber will always review your complete medication list during your consultation to ensure vardenafil is suitable for you, and you should never stop or change a prescribed medicine without professional advice.

What Is Vardenafil and How Does It Work?

Vardenafil is the generic name for Levitra, a prescription medicine used to treat erectile dysfunction (ED) in adult 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 [1].

Vardenafil is available in 5mg, 10mg and 20mg tablets and is typically taken about 25 to 60 minutes before sexual activity [5]. The effects can last for several hours, but you should only take it once in any 24-hour period. Like all PDE5 inhibitors, vardenafil requires sexual stimulation to work—it will not cause an erection on its own [2].

At Cured Pharmacy, vardenafil is available from £16.95 (or £13.56 for your first order with code Ednew) after an online consultation reviewed by a UK prescriber. The consultation ensures the medicine is safe and suitable for your individual circumstances.

What Is Montelukast and Why Is It Prescribed?

Montelukast is a medicine commonly prescribed for asthma and allergic rhinitis (hay fever). It belongs to a class of medicines called leukotriene receptor antagonists, which work by blocking the action of leukotrienes—chemicals in the body that cause inflammation, narrowing of the airways, and mucus production in the lungs.

Montelukast is usually taken once daily in the evening and is often used as an add-on treatment for people whose asthma is not fully controlled by inhaled corticosteroids alone. It can also help reduce symptoms of seasonal allergies. The medicine is generally well tolerated and works differently from other asthma medicines such as inhalers or oral steroids.

Because montelukast acts on the respiratory system and does not directly affect blood pressure or the enzymes that break down vardenafil, the two medicines do not have a known significant interaction. However, it is still essential to declare all your current medicines during your ED consultation so your prescriber can assess your overall health and any potential risks.

How Montelukast Differs from Other Asthma Medicines

Unlike inhaled corticosteroids or beta-agonists (such as salbutamol), montelukast does not work by opening the airways immediately. Instead, it reduces inflammation over time and is taken regularly to prevent asthma symptoms rather than to relieve them during an attack. This means it does not interact with vardenafil in the same way that some other medicines might, and it does not affect the cardiovascular system in a way that would raise concerns when combined with a PDE5 inhibitor.

Can You Take Vardenafil and Montelukast Together?

Yes, vardenafil and montelukast can generally be taken together. No major interaction is commonly reported between these two medicines, and they work on different systems in the body—vardenafil on blood flow to the penis and montelukast on inflammation in the airways.

However, your prescriber will still need to review your full medical history and all current medicines during your consultation. This is because some medicines can interact with vardenafil in ways that require dose adjustments or make the treatment unsuitable. For example, vardenafil must never be taken with nitrates, nicorandil, riociguat, or recreational drugs known as poppers, as these combinations can cause a dangerous drop in blood pressure [5].

Even though montelukast itself does not interact with vardenafil, your prescriber will check for other factors such as cardiovascular health, blood pressure, and any other medicines you are taking. This comprehensive review ensures that vardenafil is safe and appropriate for you. Always be honest and thorough when listing your medicines and health conditions during the consultation.

What Your Prescriber Checks Before Approving Vardenafil

When you request vardenafil through Cured Pharmacy, a UK-registered prescriber will review your online consultation to ensure the medicine is safe for you. They will check your cardiovascular health, blood pressure, and any conditions that might make sexual activity inadvisable, such as recent heart attack or stroke, unstable angina, or severe heart failure [2].

Your prescriber will also review all your current medicines to identify any interactions. Vardenafil is contraindicated with nitrates (such as GTN spray or isosorbide mononitrate), nicorandil, riociguat, and poppers [5]. If you take alpha-blockers for prostate problems or high blood pressure (such as tamsulosin or doxazosin), you may need to start on a lower dose of vardenafil to reduce the risk of dizziness or low blood pressure [5].

Potent CYP3A4 inhibitors—medicines that slow the breakdown of vardenafil in the body—can raise vardenafil levels and increase the risk of side effects. Examples include ritonavir, cobicistat, ketoconazole, itraconazole, and clarithromycin. Vardenafil is generally avoided or contraindicated with these medicines, so your prescriber will check the specific details in the Summary of Product Characteristics [5][12].

Why Declaring All Medicines Matters

Even over-the-counter medicines, herbal supplements, and recreational drugs can interact with vardenafil. For example, St John's wort (a herbal remedy for low mood) can reduce the effectiveness of vardenafil, and heavy alcohol can worsen erectile dysfunction and add to the blood-pressure-lowering effect [5]. Always declare everything you take, including vitamins, supplements, and occasional medicines, so your prescriber can give you the safest advice.

Practical Advice for Taking Vardenafil and Montelukast

If you have been prescribed both vardenafil and montelukast, you can take them on the same day without concern about a direct interaction. Montelukast is usually taken once daily in the evening, while vardenafil is taken on demand, about 25 to 60 minutes before sexual activity [5]. There is no need to separate the doses by a specific time interval.

However, you should follow the dosing instructions for each medicine carefully. Do not take more than one dose of vardenafil in any 24-hour period, and do not stop or change your montelukast dose without consulting your doctor, as this could affect your asthma control. If you experience any new or unusual symptoms after starting vardenafil, contact your prescriber or pharmacist for advice.

Remember that vardenafil requires sexual stimulation to work and will not cause an automatic erection [1]. It is most effective when taken on an empty stomach or after a light meal, as a heavy or high-fat meal can delay its action. Avoid grapefruit juice, as it can raise vardenafil levels in the blood, and limit alcohol, as heavy drinking can make erectile dysfunction worse and increase the risk of side effects such as dizziness [5].

When to Seek Medical Advice About Vardenafil and Montelukast

While vardenafil and montelukast can be taken together, you should seek urgent medical help if you experience certain warning signs. If you have an erection lasting more than four hours (priapism), call 999 or go to A&E immediately, as this is a medical emergency that requires prompt treatment to prevent permanent damage [5].

You should also seek urgent help if you experience sudden loss of vision or hearing, or chest pain during sexual activity. These are rare but serious side effects that require immediate assessment [5]. If you develop severe dizziness, fainting, or an allergic reaction (such as swelling of the face, lips, or throat, or difficulty breathing), call 999 straight away.

If you have any questions about taking vardenafil and montelukast together, or if you start a new medicine and are unsure whether it is safe to continue vardenafil, contact your prescriber or pharmacist. Do not stop taking montelukast without medical advice, as this could worsen your asthma. Cured Pharmacy's team is available to answer your questions and ensure you use your medicines safely and effectively.

Seeing Your GP for New Erectile Dysfunction

If you are experiencing erectile dysfunction for the first time, it is a good idea to see your GP for a check-up. ED can be an early warning sign of cardiovascular disease or diabetes, and your GP can assess your overall health, check your blood pressure and cholesterol, and discuss any underlying causes [1][2]. Treating the underlying condition can sometimes improve ED, and your GP can refer you for specialist support if needed.

Scientific References

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