Alcohol and illegal drugs

Alcohol has a wide range of effects on your body. Adding illegal drugs into the mix can have unpredictable – even fatal – results. Find out more here.

Alcohol is recognised as a ‘psychoactive substance’ by the World Health Organization, because of how it affects your brain, the way you think and feel, and your health.¹

Illegal drugs are psychoactive substances too and have a wide range of different dangerous health effects on their own. If you drink alcohol and take drugs at the same time or close together, it can have serious harmful effects as the different substances interact with each other and with your body. The effects can even be fatal.

The best advice is not to take illegal drugs at all. If you do drink alcohol, you should never combine it with illegal drugs, and always stick to the UK Chief Medical Officers’ (CMOs) low risk drinking guidelines.

If you or someone else needs urgent help after taking drugs or drinking, call 999 for an ambulance. Tell the crew everything you know. It could save their life.

What happens in the body?

Alcohol is a depressant, which means it alters the delicate balance of chemicals in your brain² and interferes with processes in your central nervous system.³

All illegal drugs have different effects of their own, which are dangerous in their own right – including depressants like heroin and tranquilisers. If you have alcohol with another depressant it can multiply the effect – putting your body at increased risk.

Some other illegal drugs have a ‘stimulant’ effect, like cocaine, ecstasy (MDMA) and other amphetamines. Combining a stimulant with alcohol can cause additional stress on your body, which can be dangerous.⁴

If you’re under the influence of drugs you are less likely to make considered decisions about how much alcohol you drink - these lowered inhibitions put you at risk of acute alcohol poisoning.

And with no quality control in the world of illegal drugs, you can never be sure of exactly what you’re taking - they can be mixed or contaminated with other harmful substances. Adding alcohol into the mix adds another risk factor to what is already a potentially lethal cocktail.

Here are some facts about what can happen when you mix certain illegal drugs with alcohol.

The UK Chief Medical Officers’ low risk drinking guidelines advise it’s safest for both men and women to drink no more than 14 units a week, spread over three or more days with several drink-free days, and no bingeing. Drinking more than this puts you at greater risk of heart disease, seven types of cancer and other health problems.

Alcohol and cannabis

Cannabis (also called marijuana or weed) is the most used illegal drug in the UK.⁵ It can have a variety of effects on people ranging from causing feelings of relaxation to being lethargic or paranoid, confused or anxious.⁶

If you use cannabis and alcohol together, the results – both physical and psychological – can be unpredictable. Drinking alcohol at the same time as using cannabis can make you feel dizzy or nauseous, or make you vomit.⁷

Never drive after smoking cannabis, or drinking alcohol. You are more likely to crash – and if you combine the two, the danger is even greater.⁸Drink driving – the law

Both cannabis and alcohol can affect your mental health too. Psychiatric effects of cannabis include panic, anxiety, paranoia and depression.⁹ Skunk, a term for stronger types of cannabis, can pose even greater risks.¹⁰

And because of the way alcohol interferes with your ‘fight or flight’ response,¹¹ drinking can make you more vulnerable to anxiety,^12,13 and make symptoms worse.¹⁴

Cannabis is usually smoked with cancer-causing tobacco too, and if you use tobacco together with alcohol there is a multiplying effect on your risk of cancer because of the way they interact.¹⁵

Alcohol makes it easier for the mouth and throat to absorb the cancer-causing chemicals in tobacco.¹⁶

Alcohol and mental health

Alcohol and stimulants

Alcohol and cocaine

Taking alcohol and cocaine together increases the risk of heart attacks, fits and even sudden death.

When alcohol and cocaine are taken together, they interact to produce a highly toxic substance in your liver called cocaethylene.¹⁷ It increases the depressive effects of alcohol on your nervous system, making your reaction to the cocaine stronger and more dangerous.

Cocaethylene takes longer to get out of your system than either alcohol or cocaine if taken on their own. This means your heart and liver are exposed to a longer period of stress - mixing alcohol and cocaine can be fatal up to 12 hours after you’ve taken them.¹⁸

Alcohol and the heart

Alcohol and ecstasy (MDMA)

Ecstasy (also known as MDMA) is a stimulant which can make people feel energised and uninhibited, while also raising body temperature and heart rate¹⁹ and contributing towards feelings of depression, anxiety and panic attacks for some users.²⁰

Ecstasy dehydrates you. So does alcohol, because it’s a ‘diuretic’ which means it makes you pee more, and sweat more.²¹ This makes it harder to keep enough fluid in your body. If you drink alcohol while taking ecstasy - you risk overheating and becoming dangerously dehydrated when you combine the two.

Both MDMA and alcohol damage your liver too.^22,23 The liver is the organ that sustains the greatest degree of tissue damage through heavy drinking, which leads to alcohol-related liver disease.²⁴

Dehydration can become serious and lead to confusion and seizures. Serious dehydration requires urgent medical attention.²⁵

Long-term use of MDMA has also been found to have links to anxiety and depression.²⁶ Long-term heavy drinking negatively impacts your mental health too²⁷ – so combining the two means there’s more than one way you’re increasing the risk to your mental health.

Alcohol and amphetamines

Amphetamines - often called ‘speed’ - are a stimulant which as well as creating feelings of alertness, increase the rate of your breathing and heart rate, and increase your blood pressure.²⁸

Taking any stimulant which makes you feel more alert can make you less aware of the effect of any alcohol you drink,²⁹ so you may end up drinking more than you realise – putting you at greater risk of acute alcohol poisoning.

Both amphetamines and alcohol reduce your inhibitions too,³⁰ you are more likely to do something you regret – and you are putting yourself at greater risk of accidents.

And just like ecstasy, amphetamines can also increase your body temperature and cause dehydration – which is heightened when you add alcohol. As amphetamines already put a lot of pressure on your heart, adding alcohol can be fatal.

How to stop drinking completely

Alcohol and depressants

Alcohol and heroin, and other opiates

Alcohol with heroin is one of the most dangerous combinations of drugs.

Alcohol lowers the amount of heroin required to fatally overdose - around half of people who die from heroin overdoses have drunk alcohol.³¹

Heroin - as well as other opiates like methadone - slows down your heart rate and breathing.³² As alcohol is also a depressant, if you combine the two, your risk of overdose increases. You are also at greater risk of choking if you vomit, as both drugs together impair your gag reflex.

Alcohol and benzodiazepines

Benzodiazepines (‘benzos’, diazepam, Valium or Xanax) are a type of depressant, which are sometimes given under prescription to treat anxiety. Possession of these types of drugs in the UK is illegal without a prescription, and there are also illegally produced ‘street benzos’ which are similar but can be far more dangerous.³³

Any medication you have been prescribed by a doctor is not illegal for your own use. Depending on what you’re taking and your health condition, drinking can make medication less effective, or lead to dangerous health consequences. Always consult with your doctor or pharmacist if you think you might want to drink any alcohol.
Alcohol and medication

Taking benzodiazepines can make you drowsy, dizzy and sometimes aggressive. Taking them with alcohol is dangerous, and increases your risk of overdose and death. That’s because they both depress your central nervous system, which affects your breathing and gag reflex.³⁴

These types of drugs have also been implicated in some cases of drink spiking.³⁵ Find out more about drink spiking here, and how you can stay safe.

Alcohol and other illegal drugs

The number of illegal drugs has increased rapidly over recent years, due to substances known as ‘new psychoactive substances’ (NPS). These have been illegal since 2010, but they were previously sometimes referred to as ‘legal highs’.

The wide range of substances in this category means they can have a wide range of very different effects. For example, prominent types of NPS include a stimulant called mephedrone (‘meow meow’) and a synthetic cannabinoid called ‘spice’. Mixing them with alcohol is dangerous - it’s impossible to definitively say exactly how they will react if you mix them together.

The best advice is not to take any illegal substances, and to avoid alcohol with them if you do.

More information

In an emergency, if you or someone else needs urgent help after taking drugs or drinking, call 999 for an ambulance. Tell the crew everything you know. It could save their life.

If you need urgent help outside of a medical emergency:

Call NHS 111
Call your GP and ask for an emergency appointment
Call Samaritans free on 116 123 or email jo@samaritans.org

For more information and advice on illegal drugs, visit the websites below.

England –Talk to Frank, or call the National Drugs Helpline on 0300 123 6600
Scotland – We Are With You
Wales - DAN 24/7, call 0808 808 2234 or text DAN to 81066
Northern Ireland – Drugs and Alcohol Info NI

Alcohol support services

If you are concerned that you or someone you care about has a problem with alcohol there is a lot of help available. Here you can find useful links and phone numbers to get the support you need.

Get support

References

[1] World Health Organization website. Health Topics – Alcohol. Available at: https://www.who.int/health-topics/alcohol#tab=tab_1 (Accessed 23 November 2022).

[2] Abrahao, K. P., Salinas, A. G., & Lovinger, D. M. (2017). Alcohol and the Brain: Neuronal Molecular Targets, Synapses, and Circuits. Neuron, 96(6), 1223–1238. https://doi.org/10.1016/j.neuron.2017.10.032

[3] Mukherjee S. (2013). Alcoholism and its effects on the central nervous system. Current neurovascular research, 10(3), 256–262. https://doi.org/10.2174/15672026113109990004

[4] Althobaiti, Y. S., & Sari, Y. (2016). Alcohol Interactions with Psychostimulants: An Overview of Animal and Human Studies. Journal of addiction research & therapy, 7(3), 281. https://doi.org/10.4172/2155-6105.1000281

[5] Gov.uk website. United Kingdom drug situation 2019: summary (31 March 2021) [Accessed 30 March 2023]. Available at: https://www.gov.uk/government/publications/united-kingdom-drug-situation-focal-point-annual-report/uk-drug-situation-2019-summary

[6] Talk To Frank. Cannabis. [Accessed 30 March 2023]. Available at: https://www.talktofrank.com/drug/cannabis#how-it-feels

[7] Talk To Frank. Cannabis. [Accessed 30 March 2023]. Available at: https://www.talktofrank.com/drug/cannabis#how-it-feels

[8] Sewell, R. A., Poling, J., & Sofuoglu, M. (2009). The effect of cannabis compared with alcohol on driving. The American journal on addictions, 18(3), 185–193. https://doi.org/10.1080/10550490902786934

[9] Talk To Frank. Cannabis. [Accessed 30 March 2023]. Available at: https://www.talktofrank.com/drug/cannabis#how-it-feels

[10] Royal College of Psychiatrists. 'Cannabis and mental health'. Available at: https://www.rcpsych.ac.uk/mental-health/parents-and-young-people/young-people/cannabis-and-mental-health-information-for-young-people [Accessed 30 March 2023]

[11] Day, E., & Daly, C. (2021). Clinical management of the alcohol withdrawal syndrome. Addiction.

[12] Holmes, A., Fitzgerald, P. J., MacPherson, K. P., DeBrouse, L., Colacicco, G., Flynn, S. M., Masneuf, S., Pleil, K. E., Li, C., Marcinkiewcz, C. A., Kash, T. L., Gunduz-Cinar, O., & Camp, M. (2012). Chronic alcohol remodels prefrontal neurons and disrupts NMDAR-mediated fear extinction encoding. Nature neuroscience, 15(10), 1359–1361. https://doi.org/10.1038/nn.3204

[13] Anker, J. (2019). Co-Occurring Alcohol Use Disorder and Anxiety: Bridging the Psychiatric, Psychological, and Neurobiological Perspectives. Alcohol Research: Current Reviews, 40(1), arcr.v40.1.03. https://doi.org/10.35946/arcr.v40.1.03

[14] Gorka, S. M., & Phan, K. L. (2017). Impact of anxiety symptoms and problematic alcohol use on error-related brain activity. International journal of psychophysiology : official journal of the International Organization of Psychophysiology, 118, 32–39. https://doi.org/10.1016/j.ijpsycho.2017.05.011

[15] Cancer Research UK. Head and neck cancers risk. (Accessed 11/10/2020)

[16] Zygogianni, A. G., Kyrgias, G., Karakitsos, P., Psyrri, A., Kouvaris, J., Kelekis, N., & Kouloulias, V. (2011). Oral squamous cell cancer: early detection and the role of alcohol and smoking. Head & neck oncology, 3, 2. https://doi.org/10.1186/1758-3284-3-2

[17] Farooq, M. U., Bhatt, A., & Patel, M. (2009). Neurotoxic and cardiotoxic effects of cocaine and ethanol. Journal of medical toxicology : official journal of the American College of Medical Toxicology, 5(3), 134–138. https://doi.org/10.1007/BF03161224

[18] Talk to Frank website. Cocaine. [Accessed 30 March 2023] Available at: https://www.talktofrank.com/drug/cocaine#mixing

[19] Talk to Frank. Ecstasy. Available at: https://www.talktofrank.com/drug/ecstasy [Accessed 30 March 2023]

[20] Talk to Frank. Ecstasy. Available at: https://www.talktofrank.com/drug/ecstasy [Accessed 30 March 2023]

[21] Hobson, R.M. and Maughan, R.J. (2010). Hydration status and the diuretic action of a small dose of alcohol. Alcohol & Alcoholism, 45(4), 366-373.

[22] Campbell, G. A., & Rosner, M. H. (2008). The agony of ecstasy: MDMA (3,4-methylenedioxymethamphetamine) and the kidney. Clinical journal of the American Society of Nephrology : CJASN, 3(6), 1852–1860. https://doi.org/10.2215/CJN.02080508

[23] Drinkaware. Alcohol-related liver disease (27 October 2021). Available at: https://www.drinkaware.co.uk/facts/health-effects-of-alcohol/alcohol-related-diseases/alcohol-related-liver-disease

[24] Teschke, R. (2019). Alcoholic liver disease: current mechanistic aspects with focus on their clinical relevance. Biomedicines, 7(3).

[25] NHS website. Dehydration (Accessed 31 March 2023). Available at: https://www.nhs.uk/conditions/Dehydration/

[26] MURPHY, PHILIP. (Ed.) The Routledge International Handbook of Psychobiology. (2018). (Routledge International Handbooks). Chapter 20 - Roberts, C.A., Montgomery, C. What is the evidence for psychobiological harm from the use of ‘ecstasy’ (MDMA). https://www.routledge.com/The-Routledge-International-Handbook-of-Psychobiology/Murphy/p/book/9780367646318

[27] Drinkaware. Alcohol and depression. (1 July 2022) Available at: https://www.drinkaware.co.uk/facts/health-effects-of-alcohol/mental-health/alcohol-and-depression

[28] Talk to Frank. Speed. Available at: https://www.talktofrank.com/drug/speed?a=Speed#the-risks [Accessed 30 March 2023]

[29] Althobaiti, Y. S., & Sari, Y. (2016). Alcohol Interactions with Psychostimulants: An Overview of Animal and Human Studies. Journal of addiction research & therapy, 7(3), 281. https://doi.org/10.4172/2155-6105.1000281

[30] Taylor, B., Irving, H.M., Kanteres, F., Room, R., Borges, G., Cherpitel, C., Greenfield, T. and Rehm, J. (2010). The more you drink, the harder you fall: a systematic review and meta-analysis of how acute alcohol consumption and injury or collision risk increase together. Drug and Alcohol Dependence, 110(1-2), 108-116.

[31] National Treatment Agency for Substance Abuse. HS, 'Does the combined use of heroin or methadone and other substances increase the risk of overdose?', 2007.

[32] Talk to Frank. Heroin. Available at: https://www.talktofrank.com/drug/heroin?a=Heroin [Accessed 30 March 2023]

[33] Talk to Frank. Benzodiazepines. Available at: https://www.talktofrank.com/drug/benzodiazepines [Accessed 5 April 2023]

[34] NHS inform. Benzodiazepines (benzos, diazepam, Valium) (8 March 2023). Available at: https://www.nhsinform.scot/healthy-living/drugs-and-drug-use/common-drugs/benzodiazepines-benzos-diazepam-valium [Accessed 11 May 2023]

[35] Talk to Frank. Benzodiazepines. Available at: https://www.talktofrank.com/drug/benzodiazepines [Accessed 5 April 2023]

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Last Reviewed: 16th May 2023

Next Review due: 16th May 2026

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