Tadalafil and Prucalopride: Can You Take Them Together?

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At a glance

What is tadalafil and how does it work?

Tadalafil is the active ingredient in Cialis and is one of the most widely used treatments for erectile dysfunction in the UK [4]. 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].

Tadalafil is available in two forms: on-demand tablets (usually 10mg or 20mg taken at least 30 minutes before sex, with effects lasting up to 36 hours) and daily low-dose tablets (2.5mg or 5mg taken once a day) [4]. Unlike some other ED treatments, tadalafil's long duration of action means you don't need to time it as precisely, which many men find more convenient.

All PDE5 inhibitors, including tadalafil, require sexual stimulation to work—they do not cause an automatic erection [2]. Tadalafil is a prescription-only medicine in the UK, and you will need a consultation with a prescriber who will check your medical history, current medicines, and whether tadalafil is suitable and safe for you.

What is prucalopride and why is it prescribed?

Prucalopride is a prescription medicine used to treat chronic constipation in adults when other laxatives have not worked adequately. It is a selective serotonin (5-HT4) receptor agonist, which means it works by stimulating receptors in the gut that increase bowel movement and help relieve constipation.

Prucalopride is usually taken as a 1mg or 2mg tablet once daily, and it can be particularly helpful for people who have not responded well to traditional laxatives. Common side effects include headache, nausea, diarrhoea, and abdominal pain, especially in the first few days of treatment.

Because prucalopride works on serotonin receptors in the digestive system and tadalafil works on blood vessels, their mechanisms of action are quite different. This is one reason why no major interaction is commonly reported between the two medicines, though your prescriber will still review your full medication list to ensure the combination is safe for you.

Can you take tadalafil and prucalopride together?

No major interaction between tadalafil and prucalopride is commonly reported in standard UK drug references. The two medicines work through different mechanisms—tadalafil affects blood flow to the penis, while prucalopride stimulates gut motility—so they do not typically interfere with each other's action.

However, it is essential that you declare all medicines you are taking, including prucalopride, when you have your consultation for tadalafil. Your prescriber or pharmacist will review your complete medical history and current medicines to check for any individual factors that might affect safety. Never assume a combination is safe without professional advice, even if no interaction is widely known.

If you are already taking prucalopride and your prescriber approves tadalafil, you should take both medicines exactly as directed. Do not stop or change the dose of either medicine without consulting your GP or prescriber first, as this could affect your treatment for constipation or erectile dysfunction.

What your prescriber will check

During your consultation for tadalafil, your prescriber will ask about all your current medicines, including prucalopride, and any other health conditions. They will check whether you have any heart or blood pressure problems, as tadalafil can lower blood pressure and is not suitable for everyone [2].

Your prescriber will also want to know if you take any medicines that are known to interact seriously with tadalafil, such as nitrates (GTN spray, isosorbide), nicorandil, riociguat, or alpha-blockers like tamsulosin or doxazosin [3][4]. These checks ensure that tadalafil is safe and appropriate for you, even if you are taking other medicines like prucalopride.

What you need to know

• No major interaction between tadalafil and prucalopride is commonly reported in standard references
• Always declare all medicines including prucalopride during your tadalafil consultation
• Never take tadalafil with nitrates, nicorandil, riociguat, or poppers—this is dangerous
• Tadalafil is prescription-only and requires a UK prescriber to review your medical history and medicines
• Contact your GP if you develop new symptoms or side effects while taking both medicines

Tadalafil and prucalopride: what to watch for

Although no major interaction is commonly reported, it is still important to be aware of how each medicine can affect you individually. Tadalafil can cause side effects such as headache, flushing, indigestion, nasal congestion, and dizziness, particularly if your blood pressure drops [4]. Prucalopride can cause headache, nausea, diarrhoea, and abdominal discomfort, especially when you first start taking it.

If you experience any new or worsening symptoms after starting tadalafil while taking prucalopride, contact your GP or pharmacist for advice. Pay particular attention to dizziness or light-headedness when standing up, as tadalafil can lower blood pressure. If you develop severe diarrhoea from prucalopride, this can lead to dehydration, which may also affect blood pressure.

Always take tadalafil as prescribed—do not take more than the recommended dose, and do not take it more often than once a day if you are using the on-demand form [4]. If you have any concerns about how the two medicines are working together, speak to your prescriber or pharmacist rather than stopping either medicine on your own.

Other medicines that interact with tadalafil

While tadalafil and prucalopride do not have a major known interaction, there are several other medicines that do interact significantly with tadalafil and must be avoided or managed carefully. Never take tadalafil 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 [3][4].

Alpha-blockers used for prostate problems or high blood pressure (such as tamsulosin, doxazosin, alfuzosin, or terazosin) can also lower blood pressure when taken with tadalafil, so your prescriber will check you are stable on the alpha-blocker and may start you on a lower dose of tadalafil [4]. Potent CYP3A4 inhibitors, including some HIV medicines (ritonavir, cobicistat), antifungals (ketoconazole, itraconazole), and antibiotics (clarithromycin), can raise tadalafil levels in your blood, so dose adjustments may be needed [4].

Other blood pressure medicines can add to the blood-pressure-lowering effect of tadalafil, which is usually manageable but must be reviewed by your prescriber [2]. Grapefruit juice can also raise tadalafil levels, so it is best avoided. Heavy alcohol can worsen erectile dysfunction and increase the risk of dizziness or low blood pressure when combined with tadalafil [1][4].

Declaring all your medicines

It is essential to tell your prescriber about every medicine you take, including prescription medicines, over-the-counter treatments, herbal remedies, and supplements. This includes prucalopride, any laxatives, blood pressure tablets, medicines for your prostate, and anything else you use regularly or occasionally.

Your prescriber cannot assess safety accurately without a complete picture of your current medicines. Even if you think a medicine is unrelated to erectile dysfunction, it may still interact with tadalafil or affect whether it is safe for you to use [2]. Always be honest and thorough during your consultation.

When to get urgent help

• Erection lasting more than 4 hours (priapism)—go to A&E immediately
• Sudden loss of vision or hearing—stop tadalafil and seek urgent medical help
• Chest pain during or after sex—stop activity, call 999, do not take more tadalafil
• Severe dizziness, fainting, or very low blood pressure—seek same-day medical advice
• Allergic reaction (swelling of face, lips, tongue, or difficulty breathing)—call 999

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

Getting tadalafil safely at Cured Pharmacy

At Cured Pharmacy, all ED treatments including tadalafil are prescription-only and are only supplied after an online consultation reviewed by a UK-registered prescriber. During your consultation, you will be asked about your medical history, current medicines (including prucalopride), and any other health conditions to ensure tadalafil is safe and suitable for you.

We offer a range of tadalafil options, including generic tadalafil from £7.95 (or £6.36 for your first order with code Ednew), branded Cialis from £12.00 (£9.60 with code Ednew), and Teva tadalafil 20mg from £9.99 (£7.99 with code Ednew). You can also choose from other PDE5 inhibitors such as sildenafil, vardenafil, or avanafil if your prescriber recommends a different option.

If you are already taking prucalopride or any other medicine, make sure you declare it clearly in your consultation. Our prescribers and pharmacists are here to help you find a safe, effective treatment for erectile dysfunction that fits with your other medicines and your lifestyle. If you have any questions, our pharmacy team is available to provide advice and support throughout your treatment.

When to see your GP

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 underlying health conditions such as heart disease, high blood pressure, or diabetes, and your GP can arrange tests and discuss treatment options [1][2].

You should also see your GP if you develop new symptoms while taking tadalafil and prucalopride, if either medicine stops working as well as it did, or if you have any concerns about side effects. Your GP can review your medicines, adjust doses if needed, and refer you to a specialist if appropriate.