Tadalafil and Nicorandil: Can They Be Taken Together?

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At a glance

What is tadalafil and nicorandil used for?

Tadalafil is a prescription medicine licensed in the UK to treat erectile dysfunction (ED) and, at lower doses, benign prostatic hyperplasia (an enlarged prostate). It belongs to a class of medicines called PDE5 inhibitors, which work by relaxing blood vessels in the penis to improve blood flow during sexual stimulation [4]. Tadalafil is available as on-demand tablets (usually 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 is the active ingredient in branded Cialis and is also available as generic tadalafil.

Nicorandil is a prescription medicine used to prevent and treat angina (chest pain caused by reduced blood flow to the heart). It works through two mechanisms: it opens potassium channels in blood vessel walls and also releases nitric oxide, which relaxes and widens blood vessels, reducing the heart's workload [12]. Nicorandil is typically prescribed for people with coronary heart disease who need additional treatment beyond other angina medicines. Because it acts partly like a nitrate medicine, nicorandil carries the same serious interaction risks with PDE5 inhibitors such as tadalafil.

Why tadalafil and nicorandil cannot be taken together

The interaction between tadalafil and nicorandil is classified as an absolute contraindication, meaning these medicines must never be used together under any circumstances [3][4]. Both medicines lower blood pressure by relaxing blood vessels, but when combined, the effect is dangerously amplified. Nicorandil releases nitric oxide, which increases levels of a substance called cyclic GMP in blood vessel walls, causing them to relax. Tadalafil works by blocking the enzyme (PDE5) that breaks down cyclic GMP, so cyclic GMP levels stay elevated for longer. When you take both medicines together, cyclic GMP accumulates to very high levels, leading to excessive blood vessel relaxation and a potentially catastrophic drop in blood pressure.

This severe hypotension (low blood pressure) can reduce blood flow to vital organs, including the heart and brain. Symptoms may include dizziness, fainting, chest pain, heart attack, or stroke. In some cases, the blood pressure drop can be fatal. Because nicorandil has nitrate-like properties, the same warning that applies to nitrate medicines (such as GTN spray or isosorbide mononitrate) also applies to nicorandil: do not take tadalafil or any other PDE5 inhibitor if you are taking nicorandil [2][4]. There is no safe dose or timing interval that makes this combination acceptable.

How long does nicorandil stay in your system?

Nicorandil is usually taken two or three times a day, and its effects on blood vessels persist while you are taking it regularly. Even if you miss a dose or stop taking nicorandil, you should not start tadalafil without consulting your doctor, as the medicine may still be affecting your cardiovascular system. Your prescriber will need to review your heart condition, discuss why you were taking nicorandil, and determine whether it is safe to stop or switch to an alternative angina treatment before considering any erectile dysfunction medicine. Never stop a prescribed heart medicine on your own, as this could worsen your angina or increase your risk of a heart attack.

What your prescriber checks before tadalafil and nicorandil

Before prescribing tadalafil, a UK prescriber will ask detailed questions about all your current medicines, including prescription drugs, over-the-counter treatments, and herbal supplements. You must declare if you take nicorandil, any nitrate medicine (GTN spray, isosorbide mononitrate, isosorbide dinitrate), riociguat, or use recreational nitrites (poppers), as all of these are absolute contraindications to PDE5 inhibitors [2][3]. The prescriber will also ask about your heart health, including any history of angina, heart attack, stroke, heart failure, or abnormal heart rhythms, because erectile dysfunction medicines are not suitable when sexual activity itself poses a risk.

If you currently take nicorandil for angina, your prescriber will not be able to prescribe tadalafil or any other PDE5 inhibitor. Instead, they may refer you back to your GP or cardiologist to discuss whether your angina treatment can be adjusted. In some cases, if your heart condition is stable and well-controlled, your doctor may be able to switch you to an alternative angina medicine that does not interact with ED treatments. However, this decision must be made by the doctor who manages your heart condition, taking into account your overall cardiovascular risk. At Cured Pharmacy, our online consultation includes a thorough medication review, and our UK prescribers will not approve tadalafil if you are taking nicorandil or any other contraindicated medicine.

Declaring all your medicines during the consultation

It is essential to provide a complete and accurate list of all medicines you take during your online consultation. This includes medicines prescribed by your GP or hospital specialist, medicines bought from a pharmacy without prescription, herbal remedies (such as St John's wort), vitamins, and any recreational substances. If you are unsure of a medicine's name, check the label on the packet or your repeat prescription slip. Failing to declare nicorandil or another contraindicated medicine could result in a dangerous interaction, so always err on the side of caution and include everything. The prescriber will review your list and determine which medicines are safe to use alongside tadalafil.

What you need to know

• Tadalafil and nicorandil must never be taken together due to risk of dangerous blood pressure drop.
• All PDE5 inhibitors are contraindicated with nicorandil, including sildenafil, vardenafil, and avanafil.
• Safe ED alternatives with nicorandil include alprostadil, vacuum devices, or Eroxon gel.
• Never stop nicorandil without medical advice; speak to your GP about switching angina treatment.
• Seek emergency help immediately if you accidentally take both medicines together.

Are there safe alternatives to tadalafil if you take nicorandil?

Unfortunately, all oral PDE5 inhibitors licensed for erectile dysfunction in the UK—sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Spedra)—are contraindicated with nicorandil for the same reason [3][4][5][6]. This means that if you take nicorandil, you cannot safely use any of these tablets. However, there are other treatment options for erectile dysfunction that work through different mechanisms and do not interact with nicorandil. These include alprostadil, which is available as a urethral cream (Vitaros) or an injection into the penis (Caverject) [7]. Alprostadil works locally in the penis rather than affecting blood vessels throughout the body, so it does not cause the dangerous blood pressure drop seen with PDE5 inhibitors.

Another option is a vacuum erection device (VED), a non-drug treatment that uses a pump to draw blood into the penis and a constriction ring to maintain the erection. Eroxon, a topical gel that works through a cooling and warming effect to stimulate blood flow, is also available without prescription and does not interact with heart medicines. Your GP or a specialist erectile dysfunction clinic can discuss these alternatives with you and help you find a treatment that is safe and effective for your situation. It is also important to address the underlying cause of erectile dysfunction, which may include managing cardiovascular risk factors such as high blood pressure, high cholesterol, diabetes, smoking, and obesity [1][2].

Warning signs and when to seek urgent help with tadalafil and nicorandil

If you have accidentally taken tadalafil while on nicorandil, or if you have taken both medicines within a short time, seek emergency medical help immediately by calling 999 or going to A&E. Do not wait for symptoms to develop. Tell the healthcare team exactly which medicines you have taken, the doses, and the times. Warning signs of a dangerous blood pressure drop include severe dizziness or light-headedness, fainting or loss of consciousness, chest pain or tightness, rapid or irregular heartbeat, shortness of breath, confusion, blurred vision, or feeling extremely weak. These symptoms indicate that your blood pressure may have fallen to a dangerously low level, reducing blood flow to your heart and brain.

Even if you feel well initially, the interaction can develop over several hours as the medicines are absorbed and take effect. Do not lie down flat if you feel dizzy, as this can sometimes worsen the problem; instead, sit with your head between your knees or lie on your side. Do not try to drive yourself to hospital. If you are with someone, ask them to stay with you and monitor your condition. In hospital, treatment may include intravenous fluids, medications to support blood pressure, and close monitoring of your heart and circulation. The medical team will also assess whether the interaction has caused any damage to your heart or other organs.

What to do if you are unsure about your medicines

If you are not certain whether you take nicorandil or another contraindicated medicine, do not guess or proceed with an erectile dysfunction treatment. Check your medicine packets, your repeat prescription list from your GP surgery, or your pharmacy's dispensing records. You can also call your GP surgery or pharmacist for advice. If you have recently been prescribed a new heart medicine and are unsure of its name, ask your doctor or pharmacist to confirm whether it interacts with PDE5 inhibitors. During the online consultation at Cured Pharmacy, you can upload a photo of your medicine packets or list the names, and our prescribers will check for interactions before approving your treatment.

When to get urgent help

• Severe dizziness, fainting, or loss of consciousness after taking tadalafil and nicorandil together
• Chest pain, tightness, or pressure, especially if you have taken both medicines
• Rapid or irregular heartbeat, shortness of breath, or confusion
• Sudden vision loss in one or both eyes, or sudden hearing loss or ringing in the ears
• Erection lasting more than 4 hours (priapism), which requires immediate treatment to prevent permanent damage

Call 999 or go to A&E in an emergency, or contact NHS 111 for urgent advice.

How Cured Pharmacy can help with safe ED treatment and nicorandil

Cured Pharmacy is a GPhC-registered online pharmacy (GPhC 9012511) offering convenient, confidential access to erectile dysfunction treatments through a UK prescriber-led consultation. Our online questionnaire asks detailed questions about your medical history, current medicines, and cardiovascular health to ensure that any treatment we supply is safe and appropriate for you. If you take nicorandil, our prescribers will not approve a PDE5 inhibitor, but they can provide advice on alternative treatments and may recommend that you discuss options such as alprostadil or vacuum devices with your GP. We understand that erectile dysfunction can be a sensitive and frustrating issue, especially when heart medicines limit your treatment choices, and our team is here to support you with clear, honest information.

For men who are not taking nicorandil or other contraindicated medicines, we offer a range of licensed ED treatments at transparent prices. These include generic tadalafil from £7.95 (£6.36 with first-order code Ednew), generic sildenafil from £0.45 (£0.36 with code Ednew), vardenafil from £16.95, and Spedra (avanafil) from £20.95. Branded Cialis and Viagra are also available. All treatments are dispensed by our UK pharmacists and delivered discreetly to your door. If your consultation reveals that oral ED medicines are not suitable, we will explain why and suggest next steps, such as seeing your GP for a medication review or exploring non-drug treatments. Your safety is our priority, and we will never supply a medicine that could put your health at risk.

Starting your consultation at Cured Pharmacy

To begin, visit our website and select the erectile dysfunction treatment you are interested in. Complete the online medical questionnaire, providing full and accurate information about your health and medicines. A UK-registered prescriber will review your answers, and if treatment is approved, your medicine will be dispensed and dispatched by our pharmacy, usually within 24 hours. If the prescriber has concerns or needs more information, they will contact you. If tadalafil or another PDE5 inhibitor is not safe for you, we will explain the reason and offer guidance on alternative options. You can contact our pharmacy team at any time if you have questions about your treatment or need advice on managing erectile dysfunction alongside other health conditions.