Tadalafil and Nefopam: Can You Take Them Together?

Takes less than 2 minutes to complete 100% online

Tadalafil and Nefopam: What You Need to Know About Taking Them Together

Published: 23 October 2026

If you've been prescribed tadalafil for erectile dysfunction and nefopam for pain relief, you may be wondering whether tadalafil and nefopam can be taken together safely. The good news is that no major direct interaction between these two medicines is commonly reported in UK prescribing guidance. However, your prescriber will still review your full medication list during your consultation to ensure the combination is appropriate for you, as individual health conditions and other medicines can influence safety.

What is tadalafil and how does it work?

Tadalafil is a prescription medicine used to treat erectile dysfunction (ED) in men [1]. It belongs to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors, which work by relaxing blood vessels in the penis, allowing increased blood flow when you are sexually aroused [4]. Tadalafil is the active ingredient in branded Cialis and is also available as a generic medicine at lower cost.

Tadalafil is available in two main dosing options. The on-demand dose (10mg or 20mg) is taken at least 30 minutes before sexual activity, and its effect can last up to 36 hours, earning it the nickname 'the weekend pill' [4]. The daily dose (2.5mg or 5mg) is taken once a day at the same time, allowing for spontaneity without planning ahead. Both options require sexual stimulation to work—tadalafil does not cause an automatic erection.

Common side effects include headache, indigestion, back pain, muscle aches, flushing, and a blocked or runny nose [4]. These are usually mild and temporary. Tadalafil is only available on prescription in the UK after a clinical assessment by a registered prescriber, who will check that it is safe and suitable for you based on your medical history and current medicines.

What is nefopam and why is it prescribed?

Nefopam is a prescription-only painkiller used to relieve moderate pain, particularly when other painkillers such as paracetamol or ibuprofen have not been effective enough. It is not an opioid and does not belong to the non-steroidal anti-inflammatory drug (NSAID) group; instead, it works by acting on the central nervous system to reduce the perception of pain.

Nefopam is typically prescribed for short-term pain relief following surgery, injury, or dental procedures, and sometimes for chronic pain conditions such as arthritis. The usual dose is 30mg to 90mg three times a day, taken by mouth. Because nefopam can cause side effects such as nausea, dizziness, dry mouth, sweating, and difficulty passing urine, it is not suitable for everyone.

Nefopam should be used with caution in people with heart conditions, glaucoma, or urinary retention. It can interact with certain other medicines, including some antidepressants and medicines that affect the nervous system. Your prescriber will review your full medical history and current medicines before prescribing nefopam to ensure it is safe for you.

Is there an interaction between tadalafil and nefopam?

No major direct interaction between tadalafil and nefopam is commonly reported in UK prescribing resources or the British National Formulary. This means that, in general, the two medicines do not interfere with each other's effectiveness or cause a dangerous reaction when taken together. However, this does not mean the combination is automatically safe for everyone.

Both medicines can cause side effects that may overlap or add together. For example, nefopam can cause dizziness, and tadalafil can lower blood pressure slightly, which may also lead to dizziness or light-headedness, especially when standing up quickly. If you experience increased dizziness or feel faint when taking both medicines, you should speak to your GP or pharmacist.

It is important to remember that your prescriber will assess your individual circumstances during your consultation. They will review all your current medicines, health conditions, and any other factors that might affect how tadalafil and nefopam work in your body. You should always declare every medicine you are taking, including over-the-counter products and herbal supplements, to ensure a full safety check.

Why your prescriber reviews your full medication list

Even when two medicines do not have a direct interaction, your prescriber needs to see the full picture of your health. For example, if you are taking other medicines that lower blood pressure, add sedation, or affect your heart, the combination with tadalafil may require extra caution or a lower starting dose. Your prescriber will also check that tadalafil is not contraindicated with any of your other medicines, such as nitrates (used for angina), which must never be taken with tadalafil [4].

During your online consultation at Cured Pharmacy, you will be asked to list all your current medicines and health conditions. A UK-registered prescriber will review this information before approving your treatment. This careful review is a legal requirement and an essential safety step to protect your health.

What does your prescriber check before approving tadalafil and nefopam together?

Your prescriber will first confirm that tadalafil is suitable for you by reviewing your cardiovascular health, blood pressure, and any history of heart attack, stroke, or severe heart failure [2]. They will check that you are not taking any medicines that are absolutely contraindicated with tadalafil, such as nitrates (GTN spray, isosorbide mononitrate or dinitrate), nicorandil, riociguat, or recreational drugs known as 'poppers' (amyl or alkyl nitrites) [4]. Taking tadalafil with any of these can cause a dangerous drop in blood pressure.

If you are taking an alpha-blocker for prostate symptoms or high blood pressure (such as doxazosin, tamsulosin, or alfuzosin), your prescriber will ensure you are stable on that medicine and will usually start you on the lowest dose of tadalafil to minimise the risk of dizziness or fainting [4]. They will also check for medicines that can raise tadalafil levels in your blood, such as potent CYP3A4 inhibitors (for example, ritonavir, ketoconazole, itraconazole, or clarithromycin), which may require a dose adjustment.

Regarding nefopam, your prescriber will confirm that it is appropriate for your pain condition and that you are not experiencing side effects that could be worsened by tadalafil, such as significant dizziness or urinary symptoms. They will also ensure that neither medicine is contraindicated by your other health conditions, such as recent eye problems (sudden vision loss or NAION) or severe liver or kidney disease. This thorough review ensures that the combination of tadalafil and nefopam is as safe as possible for you.

Practical advice for taking tadalafil and nefopam safely

If your prescriber approves both medicines, take each one exactly as directed. Tadalafil on-demand tablets (10mg or 20mg) should be taken at least 30 minutes before sexual activity, with effects lasting up to 36 hours [4]. Daily tadalafil (2.5mg or 5mg) should be taken at the same time each day. Nefopam is usually taken three times a day with or after food to reduce the risk of nausea. Do not take more than the prescribed dose of either medicine.

Be aware of how you feel when you first start taking the combination. If you experience increased dizziness, light-headedness, or fainting, sit or lie down and avoid driving or operating machinery. Avoid drinking large amounts of alcohol, as this can worsen dizziness and make erectile dysfunction worse [1]. Grapefruit juice can raise tadalafil levels in your blood and should be avoided or limited.

Do not stop or change the dose of nefopam or any other prescribed medicine without speaking to your GP or pharmacist first. If you need to take a new medicine (prescribed or over-the-counter) while you are using tadalafil, check with your pharmacist or prescriber to ensure it is safe. Keep both medicines out of reach of children and store them as directed on the packaging.

What to do if you experience side effects

Common side effects of tadalafil include headache, indigestion, back pain, muscle aches, and facial flushing [4]. Nefopam can cause nausea, dizziness, dry mouth, sweating, and difficulty passing urine. Most side effects are mild and settle down as your body adjusts. If side effects are troublesome or persistent, speak to your GP or pharmacist—they may be able to adjust your dose or suggest ways to manage them.

Stop taking tadalafil and seek urgent medical help if you experience an erection lasting more than four hours (priapism), sudden loss of vision or hearing, or chest pain during sexual activity [4]. If you have severe side effects from nefopam, such as difficulty breathing, severe dizziness, or an allergic reaction (rash, swelling, difficulty swallowing), seek immediate medical attention.

How to get tadalafil safely online from Cured Pharmacy

Cured Pharmacy is a GPhC-registered online pharmacy (GPhC 9012511) offering a safe, discreet service for erectile dysfunction treatment. All prescription medicines, including tadalafil, are only supplied after an online consultation reviewed and approved by a UK-registered prescriber. You will be asked about your medical history, current medicines (including nefopam), and any health conditions to ensure tadalafil is safe and suitable for you.

We offer a range of tadalafil options to suit different needs and budgets. Generic tadalafil is available from £7.95 (or £6.36 for your first order with code Ednew), and branded Cialis from £12.00 (£9.60 with code Ednew). Tadalafil 20mg (Teva) is priced at £9.99 (£7.99 with code Ednew), and Avarante (tadalafil) 10mg at £11.49 (£9.19 with code Ednew). All prices include the prescriber consultation and discreet home delivery.

If tadalafil is not suitable for you, we also offer other PDE5 inhibitors, including sildenafil (generic Viagra) from £0.45, vardenafil (generic Levitra) at £16.95, and Spedra (avanafil) at £20.95 (all with first-order discounts using code Ednew). Your prescriber will recommend the most appropriate option based on your individual needs. If you have any questions about taking tadalafil with nefopam or any other medicine, our pharmacist-led team is here to help.

Why see your GP if you have new erectile dysfunction

If you are experiencing erectile dysfunction for the first time, it is important to see your GP for a full assessment [1]. ED can be an early warning sign of underlying health conditions such as heart disease, high blood pressure, diabetes, or high cholesterol [2]. Your GP can arrange blood tests and checks to identify and treat any underlying causes, which may improve your erections and your overall health.

Treating the underlying cause—such as improving blood sugar control, lowering cholesterol, losing weight, stopping smoking, or reducing alcohol intake—can sometimes resolve ED without the need for medication [1]. Even if you do need treatment, addressing these factors will improve your response to medicines like tadalafil and reduce your risk of future health problems. Your GP can also refer you for specialist support if needed, including psychological therapy if stress, anxiety, or relationship issues are contributing to your ED.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 23 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 23 October 2026]
3. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 23 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.