When you use cocaine and alcohol together, your body produces a third substance called cocaethylene. It’s thought to be more toxic than cocaine, especially to the heart, and stays in your body for longer.
In the UK and Ireland, mixing cocaine with alcohol has become a normal part of life for some people. But drinking while using cocaine can have unpredictable effects. The alcohol can take the edge off the high, and the cocaine can mask how drunk a person feels.
If you’re concerned about yourself or someone in your life, understanding the harm cocaethylene causes can help you decide whether something needs to change.
What is cocaethylene?
Cocaethylene is a compound your liver makes when you use cocaine and alcohol at the same time.
Normally, your liver breaks cocaine down into byproducts that leave your body fairly quickly. When alcohol is there too, some of the cocaine is turned into cocaethylene instead.
Cocaethylene is the only known psychoactive substance that’s formed entirely inside the body. Like cocaine, it keeps dopamine active in the brain for longer, but is thought to be more damaging to the heart than cocaine itself.
Cocaethylene stays active in your body roughly twice as long as cocaine, with a half-life of roughly 2–2.5 hours, compared to 1–1.5 hours for cocaine.
Why do people use cocaine and alcohol together?
A 2018 meta-analysis estimated that 74% of people who use cocaine drink alcohol at the same time.
Cocaine and beer can often be taken together on a night out, and are sometimes mixed for the combined effects.
- Cocaine can keep you sharp and alert when you have drunk enough alcohol that you would usually be sedated.
- Alcohol, in turn, takes the edge off cocaine’s side effects, like anxiety and restlessness.
Cocaethylene itself can also potentially make the high last longer and feel stronger.
What are the effects of mixing cocaine and alcohol?
Short-term effects of cocaine and alcohol combined
When you mix cocaine with alcohol, short-term effects include:
- Elevated heart rate and blood pressure
- Increased body temperature
- Impaired coordination and slower reaction times
- Heightened anxiety, paranoia, or aggression
How strong these effects are depends on how much of each you’ve taken, when you took them, in what order, and your tolerance to both substances.
Recognising a cocaethylene overdose
A 2024 systematic review found that cocaethylene makes sudden death 18 to 25 times more likely than cocaine alone, and has been linked to heart damage and cardiac arrest.
Since cocaethylene also lasts longer than cocaine, people can take more cocaine without realising the cocaethylene is still active. That raises the risk of overdose.
Signs of a cocaethylene overdose include:
- Severe chest pain
- Seizures
- Vomiting
- Tremors
- Loss of consciousness
- Extreme agitation or paranoia
If someone with you is showing these signs, call 112 or your local emergency number straight away, and wait with them until help arrives. If they’re unconscious but breathing, put them in the recovery position.
Long-term risks of cocaethylene exposure
With repeated use, the damage from cocaethylene builds up.
- Your heart takes the most strain. Cocaine puts pressure on the heart on its own, and cocaethylene adds to it, raising the risk of heart attacks and an irregular heartbeat each time it’s produced.
- Your liver is affected too. It has to process cocaethylene on top of the cocaine and alcohol. Cocaethylene is generally considered more toxic to the liver than cocaine, and repeated exposure can cause lasting liver damage.
- Cocaethylene also affects how dopamine works in the brain. With regular use, this can change how you respond to stress and reward, which is part of how a dependency forms.
Cocaethylene and mental health
Regular combined use can make existing mental health difficulties more intense and harder to manage. When someone has a mental health condition and substance dependence at the same time, it’s known as dual diagnosis.
If one goes untreated, it can cause a relapse in the other. Therapies such as Cognitive Behavioural Therapy (CBT) and Dialectical Behaviour Therapy (DBT) can help with both.
There’s also a link between using cocaine and alcohol together and suicide. A 2021 study published in Drug and Alcohol Review looked at suspected suicides in England. The more alcohol someone had in their blood, the more likely they were to have used cocaine too. A 2025 systematic review found that cocaethylene’s own role in suicide isn’t yet well understood.
If you or someone you know is having suicidal thoughts, call Samaritans free on 116 123 in the UK and Ireland. If there is an immediate risk to life, please call local emergency services.
“Addictive behaviours are not the problem itself, but a meaningful response to deeper pain, and that with the right support, those patterns can be understood, softened, and ultimately changed.”
When to seek support for cocaine and alcohol use
There’s no fixed point where casual use becomes a dependency, but there are warning signs to be aware of.
- Using more cocaine or alcohol than you planned to
- Finding it harder to have one without the other
- Noticing physical effects the day after, like chest tightness, anxiety, or low mood
- Feeling like the pattern is becoming harder to change
None of these mean you have an addiction. But they’re good reasons to think honestly about your drinking and cocaine use.
How to get support for cocaine and alcohol use
Castle Health offers a range of support, from outpatient support for cocaine and alcohol use to residential cocaine addiction treatment at Castle Craig and Smarmore Castle.
You don’t need a referral or to have made any decisions first. You can get in touch to talk through your cocaine and alcohol use and what support is available. Your GP can also check how your body is coping and refer you to specialist services.
It can help to understand how cocaine addiction develops and how alcohol dependence develops.
Worried about someone’s cocaine or alcohol use?
We can help you understand the options.
If someone in your life is using cocaine and alcohol
If someone you know keeps using cocaine when they drink, it can be a hard thing to bring up. They might not see it as a problem because they only do it when they go out, but the damage is happening whether they feel it or not.
Be specific about what you’ve noticed rather than what you think it means. You don’t need to mention cocaethylene by name, but you can share what you’ve learned about what the combination does.
Castle Health can talk you through what you’re seeing and help you work out what to do next. If the person in your life does go on to get treatment, Castle Health’s family support programme offers therapy for families during that process.
Frequently asked questions about cocaethylene
How long does cocaethylene stay in the body?
Cocaethylene half life is about two hours, roughly double cocaine’s. It can be found in urine for up to 72 hours and in blood for up to 24 hours. Saliva tests pick it up for a few hours, and hair tests can detect it for several months.
Can a doctor test for cocaethylene?
Standard drug tests look for cocaine and alcohol, not cocaethylene itself. More detailed tests can pick up cocaethylene, and finding it shows that both were used together. That gives medical teams a clearer picture of what’s been taken.
How does cocaethylene affect the heart?
Research links cocaethylene to heart damage, cardiac arrest, and a much higher risk of sudden death than cocaine alone. Your body makes it every time you use cocaine and alcohol together, so the more often you use them, the more often your heart is exposed to it.
Are there any legal implications of cocaethylene?
Cocaethylene itself isn’t separately legislated. But cocaine is illegal across Europe, and cocaethylene can appear in toxicology reports. If you’re concerned about legal consequences, seek advice from a legal professional in your country.
