Tadalafil and Dipyridamole: Can They Be Taken Together?

Tadalafil and Dipyridamole: Understanding the Interaction

Published: 20 October 2026

Many men taking dipyridamole for heart or stroke prevention wonder whether tadalafil and dipyridamole can be used together safely. The good news is that no major interaction between these two medicines is commonly reported, but because both can affect blood pressure and circulation, your prescriber will carefully review your full medical history and current medicines during your consultation. This page explains what each medicine does, how they may interact, and what safety checks are in place.

What is tadalafil and dipyridamole used for?

Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor licensed in the UK to treat erectile dysfunction (ED) [4]. It works by relaxing blood vessels in the penis, allowing increased blood flow when you are sexually aroused. Tadalafil is available as on-demand tablets (10 mg or 20 mg, taken at least 30 minutes before sex, with effects lasting up to 36 hours) or as a daily low-dose tablet (2.5 mg or 5 mg). It requires sexual stimulation to work and does not cause spontaneous erections [4].

Dipyridamole is an antiplatelet medicine that helps prevent blood clots. It is commonly prescribed after a stroke or transient ischaemic attack (TIA) to reduce the risk of further clots, often in combination with aspirin. Dipyridamole works by stopping platelets in the blood from sticking together and also has a mild blood-vessel-widening effect. It is usually taken twice daily as a modified-release capsule.

How do tadalafil and dipyridamole interact?

There is no well-documented major interaction between tadalafil and dipyridamole in the British National Formulary or standard drug-interaction databases [4]. However, both medicines can lower blood pressure to some degree. Tadalafil relaxes blood vessels to improve blood flow to the penis, which can also cause a small drop in overall blood pressure. Dipyridamole has a mild vasodilating (blood-vessel-widening) effect, particularly when first started or if the dose is increased.

When two medicines that both lower blood pressure are taken together, there is a theoretical risk of an additive effect—meaning you might feel dizzy, light-headed, or faint, especially when standing up quickly. In practice, this combination is often well tolerated, but it is important that your prescriber knows you are taking dipyridamole so they can assess your individual risk and advise on the safest starting dose of tadalafil.

Why the interaction is usually manageable

Most men taking dipyridamole for stroke prevention are stable on their dose and do not experience significant blood-pressure problems when tadalafil is added at the recommended starting dose. Your prescriber will check your current blood pressure, review any symptoms of dizziness or fainting, and ensure that sexual activity is safe for your heart. If you are already taking other blood-pressure medicines alongside dipyridamole, your prescriber may start you on a lower dose of tadalafil and monitor your response closely.

What your prescriber checks before approving tadalafil and dipyridamole together

During your online consultation at Cured Pharmacy, the UK-registered prescriber will ask about all your current medicines, including dipyridamole, aspirin, and any blood-pressure tablets. They will check your cardiovascular history—particularly any recent stroke, TIA, heart attack, angina, or heart failure—to ensure that sexual activity is safe for you. They will also ask about symptoms such as dizziness, fainting, or chest pain, which could indicate that your blood pressure is too low or that your heart condition is not stable [2].

The prescriber will review whether you are taking any medicines that are absolutely contraindicated with tadalafil, such as nitrates (GTN spray, isosorbide mononitrate), nicorandil, riociguat, or recreational drugs called poppers (amyl or alkyl nitrites). These combinations can cause a dangerous drop in blood pressure and must never be used together [4]. Dipyridamole is not in this high-risk category, so the combination is not contraindicated, but careful assessment is still essential.

Practical advice for taking tadalafil and dipyridamole safely

If your prescriber approves tadalafil, start with the lowest effective dose—usually 10 mg on-demand or 2.5 mg daily—especially if you are taking dipyridamole and other blood-pressure medicines. Take tadalafil exactly as directed: on-demand tablets should be taken at least 30 minutes before sexual activity, and daily tablets at the same time each day. Do not take more than one dose in 24 hours, and never combine tadalafil with another PDE5 inhibitor such as sildenafil or vardenafil [4].

Be cautious when standing up quickly, particularly in the first few hours after taking tadalafil, as this is when dizziness is most likely. Avoid heavy alcohol, which can worsen erectile dysfunction, increase the risk of low blood pressure, and reduce the effectiveness of tadalafil. If you feel dizzy, light-headed, or faint after taking tadalafil, sit or lie down until the symptoms pass, and let your prescriber know at your next review.

What to do if you start a new medicine

If your GP or hospital doctor prescribes a new medicine while you are taking tadalafil and dipyridamole, always tell them you are using an ED treatment. Some medicines—particularly potent CYP3A4 inhibitors such as clarithromycin, ketoconazole, or ritonavir—can raise tadalafil levels in your blood and increase the risk of side effects [4]. Your prescriber may need to adjust your tadalafil dose or choose a different antibiotic or antifungal. Never stop or change your dipyridamole or any other prescribed medicine without medical advice.

Warning signs and when to seek help with tadalafil and dipyridamole

Most men tolerate tadalafil and dipyridamole together without problems, but you should be aware of warning signs that need urgent attention. If you develop chest pain or discomfort during or after sex, stop sexual activity immediately, sit down, and call 999. Do not use GTN spray or any nitrate medicine if you have taken tadalafil in the past 48 hours, as this can cause a life-threatening drop in blood pressure [4].

Seek emergency help (999 or A&E) if you have an erection lasting more than four hours (priapism), sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing, which may be accompanied by ringing in the ears or dizziness. These are rare but serious side effects that require immediate medical treatment. If you experience severe dizziness, fainting, or a rapid or irregular heartbeat after taking tadalafil, contact your GP or NHS 111 the same day for advice.

How Cured Pharmacy can help with tadalafil and dipyridamole

Cured Pharmacy is a GPhC-registered online pharmacy (GPhC 9012511) offering a confidential, pharmacist-led consultation service for erectile dysfunction treatments. When you complete your online consultation, a UK-registered prescriber will review your full medical history, including your use of dipyridamole and any other medicines, to ensure tadalafil is safe and appropriate for you. If approved, your prescription is dispensed by our pharmacy team and delivered discreetly to your door.

We stock a range of tadalafil options to suit different needs and budgets, including generic tadalafil tablets and branded Cialis. All our ED treatments are genuine, UK-licensed medicines sourced from reputable manufacturers. If you have any questions about taking tadalafil with dipyridamole or any other medicine, our pharmacist team is available to provide advice and support throughout your treatment journey.

Why see your GP about new erectile dysfunction

If you are experiencing erectile dysfunction for the first time, it is important to see your GP for a full assessment. ED can be an early warning sign of underlying health conditions such as heart disease, high blood pressure, or diabetes [1][2]. Your GP can check your cardiovascular risk, review your medicines (including dipyridamole), and refer you for specialist tests if needed. Once your GP has assessed you, an online consultation service like Cured Pharmacy can offer a convenient way to access ongoing treatment and repeat prescriptions.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 20 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 20 October 2026]
3. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 20 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.