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.
Part of our complete guide to erectile dysfunction in the UK.
Key fact: The one absolute rule is never combine Cialis (tadalafil) with nitrate medicines or nitrate-based recreational drugs — 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 UK 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 already covered on our product page and in the Tadalafil UK 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.
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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) | Sometimes prescribed alongside tadalafil under medical supervision. This should only be done with a prescriber overseeing both medicines together, not self-combined. |
| Doxycycline and other antibiotics | No significant interaction with tadalafil for most common antibiotics. A small number of antibiotics (e.g. clarithromycin) can raise tadalafil levels — see the blood pressure and CYP3A4 note 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. |
| Prednisone 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. |
| Adderall, Vyvanse and other prescribed ADHD stimulants | 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 cardiac and blood-pressure medicines are the interaction category that matters most clinically. The short version: nitrates (GTN spray, isosorbide mononitrate, nicorandil) are an absolute contraindication with no exceptions, while alpha-blockers such as tamsulosin (Flomax) and other antihypertensives like amlodipine, bisoprolol or metoprolol call for caution and careful timing rather than an outright ban. For the full clinical picture — including why the nitrate interaction is so dangerous and how cardiovascular risk is assessed before prescribing — see our dedicated guide to erectile dysfunction and heart disease.
Call 999 immediately if: you've taken Cialis and then need nitrate treatment for chest pain, or if you experience sudden chest pain, severe dizziness or fainting after taking it.
Cialis and Alcohol
Moderate alcohol (one to two units) is generally considered lower risk with tadalafil than with some other ED medicines, thanks to its longer, steadier profile — see the alcohol guidance on our Cialis product page for the specifics. Drinking heavily is a different matter: it can independently make it harder to get an erection, and combined with tadalafil it increases dizziness and makes side effects like headache and flushing more noticeable.
Cialis and Recreational Drugs
Recreational drug use: Combining Cialis with stimulant drugs — including cocaine, MDMA and methamphetamine — is not advised. Both PDE5 inhibitors and stimulants can raise heart rate and blood pressure, and using them together adds extra cardiovascular strain that a prescriber can't safely screen for outside a clinical setting. "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) and similar libido-boosting peptides or supplements are not licensed for use in the UK and are not something a GPhC-registered pharmacy will prescribe alongside tadalafil, because their interaction profile hasn't gone through the same regulatory testing as licensed medicines. 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.
Call 999 immediately if: you develop an erection lasting longer than four hours (priapism), sudden chest pain, or any sudden change in vision or hearing.
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 prednisone or other steroids?
There's no well-established direct interaction between tadalafil and prednisone 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 Adderall or Vyvanse?
Adderall, Vyvanse and other prescribed ADHD stimulants 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 cause a drop in blood pressure, dizziness or fainting, particularly on standing up. Many men take both safely under medical supervision, but a prescriber needs to know you're taking it so the dose and timing can be managed carefully.
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 cardiovascular load and is not something a prescriber can safely screen for outside a clinical setting.
Can I use Cialis with PT-141 (bremelanotide) or other libido supplements?
PT-141 (bremelanotide) is not licensed for use in the UK and isn't prescribed by regulated UK pharmacies alongside tadalafil, as its interaction profile hasn't been established through the same regulatory testing. 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, taken as needed or as a low daily dose.
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 (MHRA). Cialis Summary of Product Characteristics. medicines.org.uk
- NHS. Erectile dysfunction (impotence). nhs.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. Cialis (tadalafil) is a prescription-only medicine — a clinical consultation is required before it can be dispensed. In a medical emergency, call 999.