Cialis Drug Interactions: Medicines, Alcohol and Recreational Drugs to Avoid
What should I not take with Cialis? The everyday medicines, alcohol and recreational drugs UK patients ask about most.
When to get urgent help: Call 999 if you get chest pain during or after sex (tell the paramedics you have taken tadalafil, as nitrates such as GTN must not be given), severe dizziness or fainting, or signs of a serious allergic reaction. Go to A&E straight away if an erection is painful or lasts more than 2 hours (do not drive yourself). Stop tadalafil and go to A&E straight away if you have a sudden decrease or loss of vision or hearing.
Part of our complete guide to erectile dysfunction in the UK.
Key fact: The most important rule is never to combine Cialis (tadalafil) with nitrate medicines, nicorandil, “poppers” or riociguat — this can cause a dangerous fall in blood pressure. Beyond that headline warning, this guide covers the specific everyday medicines, alcohol and recreational drugs people ask about most, in more depth than a standard patient information leaflet.
For the core interactions list, dosage and how tadalafil works, see our complete Tadalafil Uses guide or the Cialis and generic tadalafil product pages.
If you've been prescribed Cialis — or are thinking about it — the core warnings (nitrates, alpha-blockers, alcohol) are also covered on our product page and in the Tadalafil Uses guide. This article goes further, into the specific medicines, supplements and recreational substances people most commonly ask about that aren't covered in the standard patient leaflet.
If you have questions about your specific combination of medicines, the safest first step is a clinical consultation. You can discuss your full medication list with a prescriber before ordering Cialis (tadalafil) through Access Doctor.
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Start Your Consultation →Everyday Medicines and Cialis
Most of the medicines people ask about don't have a dangerous direct interaction with tadalafil, but several are still worth flagging at consultation because of what they do to your blood pressure, heart rate or bleeding risk.
| Medicine | What to know |
|---|---|
| Aspirin, ibuprofen and other painkillers | No significant direct interaction with tadalafil. If you take aspirin regularly as a blood thinner, mention it so your bleeding risk can be reviewed alongside ED treatment. |
| Sudafed / pseudoephedrine (decongestants) | Decongestants can raise blood pressure and heart rate in their own right. Combined with tadalafil's blood-pressure-lowering effect, the net effect on any one person can vary — worth a quick check if you use decongestants often. |
| Gabapentin | No well-established interaction with tadalafil, but gabapentin can cause dizziness on its own, which may be more noticeable when combined with any PDE5 inhibitor. |
| Trazodone and other antidepressants | No dangerous direct interaction is established, but some antidepressants and trazodone can independently affect blood pressure and, rarely, cause a prolonged erection — always disclose these at consultation. |
| Dapoxetine (used for premature ejaculation) | Dapoxetine should not be used by men taking a PDE5 inhibitor such as tadalafil, because the combination can cause dizziness or fainting on standing (orthostatic hypotension). Tell your prescriber if you take dapoxetine or are thinking of starting it. |
| Doxycycline and other antibiotics | No significant interaction with tadalafil for most common antibiotics. A small number of antibiotics (such as clarithromycin and erythromycin) can raise tadalafil levels — see medicines that change tadalafil levels below. |
| Apixaban (Eliquis) and other anticoagulants | No direct interaction with tadalafil itself, but always disclose anticoagulant use so your overall cardiovascular and bleeding risk can be assessed. |
| Prednisolone (prednisone in the US) and other corticosteroids | No well-established direct interaction with tadalafil. Longer courses of steroids can affect blood pressure and fluid balance, so it's still worth mentioning at consultation, particularly if you're on a high dose or long-term course. |
| ADHD stimulants such as lisdexamfetamine (Elvanse; Vyvanse in the US), dexamfetamine, methylphenidate or Adderall (not licensed in the UK) | These raise heart rate and blood pressure in their own right. Combined with tadalafil, the cardiovascular effects can be more noticeable, so a prescriber will want to know about them — this is different from recreational stimulant use (see below), as prescribed stimulants are taken under medical monitoring. |
Blood Pressure Medicines and Alpha-Blockers
Tadalafil itself lowers blood pressure, so heart and blood-pressure medicines are the interaction group that matters most. Nitrates (GTN spray, tablets or patches, isosorbide mononitrate or dinitrate) and nicorandil must never be taken with tadalafil, and neither must riociguat (for high blood pressure in the lungs). Because tadalafil lasts so long, at least 48 hours should pass after a dose before a nitrate is given. Taking tadalafil with the alpha-blocker doxazosin is not recommended. Other alpha-blockers such as tamsulosin (Flomax), and blood pressure medicines such as amlodipine, bisoprolol or ramipril, need caution rather than an outright ban — your prescriber will check your blood pressure and how you take them. For the full picture, including how heart risk is assessed before prescribing, see our guide to erectile dysfunction and heart disease.
Call 999 immediately if: you get chest pain, severe dizziness or fainting after taking Cialis. Tell the paramedics you have taken tadalafil and when, because nitrates such as GTN must not be given within 48 hours of a dose.
Medicines That Change Tadalafil Levels
Some medicines slow down how quickly the body clears tadalafil, which raises the level in your blood and makes side effects more likely. Others speed it up, so tadalafil may not work as well.
| Medicine | What to know |
|---|---|
| HIV medicines such as ritonavir | Can greatly raise tadalafil levels. Your prescriber may advise a lower dose or a different ED medicine. |
| Antifungals such as ketoconazole and itraconazole | Can raise tadalafil levels. Your prescriber may advise a lower dose. |
| Antibiotics such as clarithromycin and erythromycin | Can raise tadalafil levels, Mention any antibiotic you are prescribed. |
| Rifampicin and some epilepsy medicines (such as carbamazepine, phenytoin and phenobarbital) | Can lower tadalafil levels, so it may not work as well. |
| Grapefruit juice | Can raise tadalafil levels. Do not drink grapefruit juice while taking tadalafil. |
| Other ED medicines (sildenafil, vardenafil, avanafil) | Do not take two ED medicines together. |
Cialis and Alcohol
A small amount of alcohol is unlikely to cause problems with tadalafil. Drinking heavily is a different matter: alcohol can lower your blood pressure, and together with tadalafil it makes dizziness — especially on standing up — more likely. Heavy drinking can also make it harder to get an erection and make side effects such as headache and flushing more noticeable, so keep alcohol low when you take tadalafil – the Cialis leaflet advises avoiding excessive drinking (a blood alcohol level of 0.08% or more).
Cialis and Recreational Drugs
Recreational drug use: Combining Cialis with stimulant drugs — including cocaine, MDMA and methamphetamine — is not advised. Stimulants raise heart rate and blood pressure and put strain on the heart, while tadalafil lowers blood pressure; using them together adds unpredictable strain on your heart and circulation that a prescriber cannot safely plan for. "Poppers" (amyl or butyl nitrite) fall into the same category as prescription nitrates and must never be combined with Cialis under any circumstances. Cannabis doesn't have a formally documented interaction with tadalafil, but it can independently raise heart rate and lower blood pressure, particularly at higher doses, so the combined effect can feel stronger than either substance alone.
If you use any recreational substances, it's worth telling your prescriber. This information is treated confidentially, and it genuinely changes what's safe to prescribe and how you're advised to use it.
Supplements and Unlicensed Products
PT-141 (bremelanotide) has no UK licence (in the US it is approved only for low sexual desire in premenopausal women, not for men), and it can temporarily raise blood pressure. Its use alongside tadalafil has not been studied, so UK-regulated prescribers will not supply it with tadalafil. Beyond any theoretical interaction with Cialis, unlicensed supplements carry their own risks — unverified ingredients, inconsistent dosing, and no quality assurance.
When to Seek Urgent Help
When to seek in-person care: contact a doctor promptly if you feel persistently dizzy, faint, or unusually unwell after combining Cialis with any medicine, alcohol or other substance.
Get urgent help if: you have chest pain, severe dizziness or fainting (call 999 and say you have taken tadalafil), an erection that is painful or lasts more than 2 hours (go to A&E straight away), or a sudden decrease or loss of vision or hearing (stop tadalafil and go to A&E straight away).
UK safety and prescribing information
- Legal status: most tadalafil, including Cialis 10mg and 20mg, is a prescription-only medicine (POM) in the UK; tadalafil 10mg sold as a pharmacy medicine, such as Cialis Together, can be bought by men aged 18 and over after speaking with a pharmacist. Access Doctor supplies MHRA-licensed UK medicines, dispensed by our GPhC-registered pharmacy (#9011198) only after a prescriber has assessed your consultation.
- Never combine with: nitrates (including GTN spray), nicorandil, “poppers”, riociguat or another ED medicine.
- Tell your prescriber about: every medicine you take, including alpha-blockers, finasteride or dutasteride, other blood pressure medicines, HIV medicines, antifungals, antibiotics, epilepsy medicines and anything bought over the counter or online.
- Driving: tadalafil can cause dizziness. Check how it affects you before driving or using machinery.
- Unlicensed products: “herbal” or imported ED products sold online can contain undeclared medicines that interact with tadalafil. Only buy from a GPhC-registered pharmacy.
Speak to a Prescriber Before Combining Medicines
Every Access Doctor consultation includes a full medicines and health check before Cialis is prescribed.
Start Your Consultation →Frequently Asked Questions
Can I take Cialis with prednisolone (prednisone) or other steroids?
There's no well-established direct interaction between tadalafil and prednisolone (called prednisone in the US) or other corticosteroids. Longer courses of steroids can affect blood pressure and fluid balance, so it's worth mentioning at your consultation, particularly if you're on a high dose or a long-term course.
Can I take Cialis with Elvanse (Vyvanse), Adderall or other ADHD stimulants?
ADHD stimulants such as lisdexamfetamine (Elvanse, sold as Vyvanse in the US), dexamfetamine and methylphenidate, and Adderall (not licensed in the UK), raise heart rate and blood pressure, and combining them with tadalafil can make these cardiovascular effects more noticeable. This is different from recreational stimulant use, as prescribed stimulants are taken under medical monitoring, but it's still worth flagging at consultation.
Can I take aspirin or ibuprofen with Cialis?
There's no significant direct interaction between tadalafil and aspirin or ibuprofen. If you take aspirin or another blood thinner regularly, mention this at your consultation so your overall bleeding and cardiovascular risk can be reviewed.
Can I take Cialis with Flomax (tamsulosin)?
Tamsulosin (Flomax) is an alpha-blocker, and combining it with tadalafil can lower blood pressure in some men, causing dizziness or, rarely, fainting, particularly on standing up. Many men take both safely under medical supervision, but a prescriber needs to know you're taking it so your blood pressure and dose can be checked. Taking tadalafil with doxazosin, another alpha-blocker, is not recommended.
Is it safe to take Cialis with antidepressants or trazodone?
There's no well-established dangerous interaction between tadalafil and most antidepressants or trazodone, but both trazodone and some antidepressants can independently affect blood pressure and, rarely, cause priapism, so a prescriber will want the full picture before prescribing.
Can I take Cialis with cannabis or marijuana?
There's no formally documented drug interaction between tadalafil and cannabis, but cannabis can independently raise heart rate and cause dizziness or a drop in blood pressure, especially in higher doses. Combining the two can make these effects more noticeable, so caution is sensible.
Is it dangerous to combine Cialis with MDMA, cocaine or methamphetamine?
Yes, this combination isn't advised. Stimulant drugs such as MDMA, cocaine and methamphetamine increase heart rate and blood pressure and can strain the cardiovascular system; combining them with a PDE5 inhibitor like tadalafil adds further strain on the heart and circulation, and is not something a prescriber can safely plan for.
Can I use Cialis with PT-141 (bremelanotide) or other libido supplements?
PT-141 (bremelanotide) has no UK licence, is not approved for men, can temporarily raise blood pressure, and has not been studied with tadalafil, so UK-regulated prescribers will not supply it alongside Cialis. Unlicensed supplements sold for libido or performance carry their own risks around unverified ingredients and dosing, separate from any interaction with Cialis itself.
Getting Cialis From Access Doctor
Every Access Doctor consultation asks for a full list of your current medicines, supplements and relevant health conditions before a prescription is issued, so interactions are screened before anything is dispensed. Branded Cialis and generic tadalafil are both available, and orders are dispatched in discreet, plain packaging.
Erectile Dysfunction · Rx
Cialis
Branded tadalafil 10mg and 20mg, taken as needed.
View product →Erectile Dysfunction · Rx
Tadalafil
The generic form of Cialis, with the same active ingredient.
View product →References
- NICE CKS. Erectile dysfunction. cks.nice.org.uk
- British National Formulary (BNF). Tadalafil. bnf.nice.org.uk
- Electronic Medicines Compendium. Cialis 10mg and 20mg film-coated tablets: Summary of Product Characteristics. medicines.org.uk
- NHS. Tadalafil (Cialis). nhs.uk
- NHS. Erectile dysfunction (impotence). nhs.uk
- Medicines and Healthcare products Regulatory Agency. Yellow Card scheme: report a suspected side effect or a fake medicine. yellowcard.mhra.gov.uk
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. Most tadalafil, including Cialis 10mg and 20mg, is a prescription-only medicine and needs a clinical assessment before it can be supplied. In a medical emergency, call 999.
Reporting side effects: If you think a medicine has caused a side effect, you can report it to the MHRA through the Yellow Card scheme at yellowcard.mhra.gov.uk or the Yellow Card app. You can also report suspected fake or unlicensed medicines. Reporting helps keep medicines safe for everyone in the UK.