Tadalafil and Lurasidone: Can They Be Taken Together?

Tadalafil and Lurasidone: Understanding the Interaction

Published: 23 October 2026

Many men taking lurasidone for mental health conditions wonder whether tadalafil and lurasidone can be used together safely. The good news is that no major direct interaction between tadalafil (a treatment for erectile dysfunction) and lurasidone (an antipsychotic medicine) is commonly reported in clinical practice. However, both medicines can affect blood pressure, and your prescriber will carefully review your full medical history and current medications to ensure the combination is appropriate for you.

What is tadalafil and lurasidone used for?

Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor licensed in the UK to treat erectile dysfunction (ED) and, in some cases, benign prostatic hyperplasia [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 (10mg or 20mg, taken at least 30 minutes before sex, with effects lasting up to 36 hours) or as a daily low-dose option (2.5mg or 5mg). It requires sexual stimulation to work and does not increase libido on its own.

Lurasidone is an atypical antipsychotic medicine used to treat schizophrenia and, in some countries, bipolar depression. It works by modulating dopamine and serotonin receptors in the brain. Like many antipsychotic medications, lurasidone can sometimes contribute to sexual side effects, including erectile dysfunction, though the mechanism is complex and varies between individuals. If you are experiencing ED while taking lurasidone, it is important to discuss this with your GP or psychiatrist, as the underlying mental health condition, the medication, or other factors may all play a role.

How do tadalafil and lurasidone interact?

There is no well-documented pharmacokinetic interaction between tadalafil and lurasidone—that is, neither medicine is known to significantly alter the blood levels of the other. Lurasidone is primarily metabolised by the liver enzyme CYP3A4, and while tadalafil is also partly metabolised by CYP3A4, it is not a strong inhibitor or inducer of this enzyme. This means the two medicines are unlikely to interfere with each other's breakdown in the body.

However, both tadalafil and lurasidone can lower blood pressure. Tadalafil does this by relaxing blood vessels, and lurasidone may cause orthostatic hypotension (a drop in blood pressure when standing up), particularly when treatment is started or the dose is increased. When used together, there is a theoretical risk that the blood-pressure-lowering effects could add up, leading to dizziness, light-headedness, or fainting. This is why your prescriber will check your blood pressure, review your dose of lurasidone, and ensure you are stable on your mental health medication before prescribing tadalafil.

What does this mean in plain English?

In simple terms, tadalafil and lurasidone do not directly interfere with each other's action, but both can make your blood pressure drop. If you stand up too quickly or take both medicines when you are not yet stable on lurasidone, you might feel dizzy or faint. Your prescriber will take this into account and may start you on a lower dose of tadalafil, or advise you to take it at a time of day when you are less likely to experience dizziness.

What will my prescriber check before prescribing tadalafil and lurasidone together?

When you request tadalafil through an online consultation at Cured Pharmacy, our UK-registered prescribers will ask about all your current medicines, including lurasidone, and review your medical history [2]. They will check that you are stable on your antipsychotic medication, that your blood pressure is within a safe range, and that you do not have any contraindications to PDE5 inhibitors (such as recent heart attack, unstable angina, or use of nitrate medicines).

Your prescriber will also ask about any other medicines you take, because some drugs can interact more significantly with tadalafil. For example, potent CYP3A4 inhibitors (such as ritonavir, ketoconazole, or clarithromycin) can raise tadalafil levels and require dose adjustments [4]. Alpha-blockers (used for prostate or blood pressure problems) also increase the risk of low blood pressure when combined with tadalafil, so you must be stable on the alpha-blocker and start on the lowest dose of tadalafil. It is essential to list every medicine, supplement, and recreational substance you use, so the prescriber can make a safe, informed decision.

Are there any medicines I must not take with tadalafil?

Yes. Do not take tadalafil together with nitrates (such as glyceryl trinitrate spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, or amyl/alkyl nitrites (poppers) [3][4]. Combining tadalafil with any of these can cause a dangerous, potentially life-threatening drop in blood pressure. You must also not take tadalafil at the same time as another PDE5 inhibitor (such as sildenafil, vardenafil, or avanafil).

If you are prescribed any new medicine by your GP or hospital doctor while you are taking tadalafil, always tell them you are using a PDE5 inhibitor. Likewise, if you are considering over-the-counter medicines or herbal supplements (for example, St John's wort, which can reduce tadalafil's effectiveness), check with your pharmacist first. Grapefruit juice can also raise tadalafil levels and should be avoided or limited.

What about recreational drugs?

Never use poppers (amyl or alkyl nitrites) with tadalafil, as this combination can cause a severe drop in blood pressure. Heavy alcohol can worsen erectile dysfunction and add to the blood-pressure-lowering effect of tadalafil, so it is best to drink only in moderation. If you use any other recreational substances, discuss this honestly with your prescriber, as some may interact or affect your heart and blood pressure.

Practical advice for taking tadalafil and lurasidone safely

If your prescriber approves the combination, take tadalafil exactly as directed. For on-demand use, take one 10mg or 20mg tablet at least 30 minutes before sexual activity; the effect can last up to 36 hours, so you do not need to take it every day. If you are prescribed daily tadalafil (2.5mg or 5mg), take it at the same time each day, with or without food. Lurasidone should be taken with food (at least 350 calories) to ensure proper absorption, so plan your doses accordingly if you are taking both medicines.

Stand up slowly from sitting or lying down, especially in the first few days of treatment or if your lurasidone dose has recently changed, to minimise the risk of dizziness. Stay well hydrated, and avoid heavy alcohol. If you feel dizzy, light-headed, or faint, sit or lie down until the feeling passes, and contact your GP or pharmacist for advice. Do not drive or operate machinery if you feel unwell.

Sexual activity itself can put strain on your heart, so tadalafil is not suitable if your doctor has advised you to avoid sex due to heart problems [1][2]. If you experience chest pain during sex, stop immediately, do not take nitrates, and seek urgent medical help. Always attend follow-up appointments with your GP or psychiatrist to monitor your mental health and any side effects from lurasidone or tadalafil.

What are the warning signs to watch for with tadalafil and lurasidone?

Most men tolerate tadalafil well, but you should be aware of certain warning signs that require urgent medical attention. If you develop an erection that lasts longer than four hours (priapism), go to A&E immediately, as this can cause permanent damage if not treated promptly. Sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing (sometimes with ringing in the ears or dizziness), are rare but serious side effects; stop taking tadalafil and seek medical help straight away [4].

If you experience severe dizziness, fainting, or a very fast or irregular heartbeat, this may indicate that your blood pressure has dropped too low. Sit or lie down, and call 111 or your GP for advice. Chest pain during or after sex requires immediate attention: do not take nitrates, and call 999. If you notice any new or worsening mental health symptoms while taking lurasidone and tadalafil together, contact your psychiatrist or GP, as adjustments to your treatment plan may be needed.

Common side effects

Common side effects of tadalafil include headache, indigestion, back pain, muscle aches, flushing, and nasal congestion [4]. These are usually mild and short-lived. Lurasidone can cause drowsiness, nausea, restlessness, and weight changes. If any side effect becomes troublesome or does not go away, speak to your pharmacist or doctor. Never stop taking lurasidone suddenly without medical advice, as this can lead to withdrawal symptoms or a relapse of your mental health condition.

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.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 23 October 2026]
4. 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.