Drug-related deaths have been on the rise in the United States and Europe in recent years. These include direct deaths from drug misuse, such as overdosing and suicide, and indirect deaths, or those that cause diseases that, in the long term, lead to demise.

The drugs that can kill are varied - illicit drugs for recreational use, prescriptions drugs that are being abused, and alcohol which is not technically a drug in the sense that doctors don’t prescribe it to treat a disease, but it is just as dangerous for its addictive feature.

Surprisingly or not, cannabis is not on the list. Although it is the most commonly used drug in the US and the UK, second only to alcohol, it does not cause heart attacks or cardiovascular arrests that could bring on death. That’s not reason though for people hooked on marijuana not to take cannabis detox seriously.

The top 10 drugs that can kill are based on the lists from governments and support agencies that focus on the drug issues affecting societies. Most deaths arise from a combination of substances, i.e., heroin and alcohol, cocaine and ecstasy.

Topping the list are opioids and alcohol.

In no particular order, these are the top 10 drugs that can take the lives of those misusing them.


Heroin overdose that results in death remains at high levels in the United States (1) and is also the cause of death by overdose in almost 9 out of 10 cases in the United Kingdom. (2)

The drug is classified as an opioid and is one of the oldest drugs that causes addiction. Originally used legally as a potent painkiller, heroin produces a euphoric effect on the user. It is also a highly addictive drug.

Heroin is injected, smoked, or snorted. The user experiences a rush of pleasurable feeling and an absence of pain. This lasts for about 20 to 30 minutes and is followed by drowsiness. In the body, the heart and lung functions slow down.

In heroin overdose, the sleepiness becomes uncontrollable, and the body organs operate at a very slow pace while the user is asleep.

In prolonged heroin use, the body develops a tolerance for the drug and will need increasing quantities of it to experience the desired effects. After the high, the user becomes abnormally sleepy to the point that the heart may stop beating and breathing practically stops.

The lungs and brain are deprived of oxygen, and the user suffers brain damage or goes into a coma or worse, dies.

Abbeycare offers treatment for Heroin addiction. A rehab programme for heroin misuse typically consists of a multi-modality approach to help you understand, and begin to overcome, the causal issues behind heroin misuse.


Deaths from cocaine misuse more than doubled in the UK from 2015 to 2019, records from the Office for National Statistics show. A similar rise was also seen in the US. Over the years, cocaine is the second most abused illicit drug after marijuana and has a very strong addictive property.

Addiction to cocaine comes from the euphoria it gives to the user and the changes it brings to the brain’s reward circuit so that a person who experiences its effects goes back again and again to using cocaine. 

Aside from the high, cocaine gives its user the self-confidence to be with people. It also increases energy, libido, wakefulness, and sociability. But the effects do not last long, driving the person to use it more frequently and in higher doses when tolerance to the drug has developed.

Cocaine abuse raises the blood pressure, heart rate, breathing, and body temperature. A cocaine overdose can lead to brain seizure, heart attack, stroke, and respiratory failure, all of which can cause death.

A fatal cocaine overdose can occur during withdrawal if the person who wants to quit using the drug does not seek professional cocaine rehab. Without medical supervision, a user might not be able to resist the cravings and has an overdose. Or the depression that is a withdrawal symptom will drive them to suicide.

Detoxification from Cocaine. As the first step of cocaine addiction treatment, it’s important to cleanse the body of cocaine itself. Once stability is achieved, therapeutic help can begin in earnest.


More popularly known as crystal meth, speed or ice, this stimulant chemical is a highly addictive drug that is taken in many ways but most commonly snorted in powder form, smoked through a glass pipe, or freebased, where it is put on tin foil and heated underneath, then inhaled using a straw.

Recent years show an increase in deaths from meth overdose globally, in a study done by the United Nations Office on Drugs and Crime.(3) Although it is a medication for ADHD, it is also sold illegally as a party drug that people take to increase wakefulness and energy, produce euphoria, and enhance sexual activity. Chronic use leads to taking bigger amounts of the drug and increasing the frequency.  

An overdose of methamphetamine increases the heart rate and blood pressure, creates respiratory distress, hypothermia, and convulsions. Any of these effects may cause brain damage or cardiovascular failure that leads to death.


Fentanyl is the generic name for a legally prescribed narcotic analgesic mostly used after inpatient surgery. It may also be prescribed for chronic or severe pain. Since it is an extremely potent opioid (50 to 100 times stronger than morphine), the brain adapts to it quite quickly and develops tolerance, so its desired outcome (extreme ecstasy) diminishes after constant use.

Fentanyl as a street drug is often mixed with heroin or cocaine to increase profits since Fentanyl is cheaper yet more potent. More recently, they are sold as counterfeit tablets taken orally. And, as illicit drug makers become more creative, fentanyl analogues (drugs with similar structure but chemically different) have been fabricated to circumvent laws. Their potency has led to overdose deaths, making Fentanyl and its analogues the 2nd and 3rd highest numbers of drug overdose in 2017. (4)

The danger in a Fentanyl overdose lies in the person using heroin or cocaine and not knowing that Fentanyl has been mixed in them. An overdose signals the brain’s respiratory centre to slow down breathing or stop completely. When the brain is deprived of oxygen, the person goes into a coma or dies.

Because Fentanyl is extraordinarily strong, its action is swift and intense, and the user may not be able to recover even with medication.

Fentanyl is up to 100 times more potent than heroin, and delivers a very rapid, short-lived, spike in euphoria levels, followed by a quick “crash” phase, leaving users quickly seeking more. 


“Benzos”, as they are usually called, are categorized as tranquilizers, and have a sedating effect. They are often prescribed by doctors to treat anxiety and insomnia. Most common brands are Valium, Xanax, Klonopin and Ativan. They are usually abused as a secondary drug of choice, in conjunction with heroin or alcohol as the primary drug. Taken alone, benzodiazepines are rarely lethal.

Abusers of benzos are of two types: some take them deliberately to get a high while others begin with legitimate use and develop a dependence on the drug. Reasons for adding benzos to other drugs are to relieve tension, enhance the euphoria that opioids give, or to combat the insomnia they cause. (5)

How does a benzodiazepine misuse lead to possible death? Opioids and alcohol act on the respiratory function of the body by slowing down breathing. A sedative drug like a benzo does the same. Taken together with another drug, they are potent enough to suppress breathing and cause brain damage, coma, or death.


Ecstasy, also called Molly, is the street name for MDMA, a synthetic chemical that is both a stimulant and a hallucinogen. It comes in tablet or capsule form and is popular among teens and young adults.

The effects of Ecstasy manifest 45 minutes after ingestion, peak 15 minutes later and last for up to three hours or more. Two tablets are the usual dose, with the second tablet taken when the effects of the first start to wane.

MDMA creates an intense feeling of wellbeing and optimism, amplified sociability, heightened emotional warmth, distorted perception, and vigorous physical activity. Users are seen to engage in risky sexual behaviour more than alcohol abusers. (6)

Ecstasy becomes dangerous and lethal because it causes the body temperature to rise to as high as 42 degrees Celsius. This abnormal temperature is sustained when tablets are taken in succession accompanied by frenzied activity like dancing. In this scenario, heatstroke ensues, and the organs start shutting down, causing death.

While short term detox treatment options for Ecstasy are available, successful addiction treatment for ecstasy misuse usually involves tackling both the physical, and mental health, symptoms as they manifest for each individual.


In most countries, alcohol is the most commonly abused substance after nicotine. But because alcohol is legal and is associated with good times, alcohol misuse disorder often goes unnoticed until it has progressed to the point that it is negatively affecting the person’s life and work.

Alcohol use disorder occurs when consumption becomes uncontrollable, the person craves for it and financial and work problems arise from drinking. The drinker places more importance on drinking over meeting personal responsibilities. Behaviour changes are also evident.

Alcohol use disorder in the US is measured by criteria set by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) (7) and in the UK, the government’s National Health Service (8) sets a limit of 14 units per week for both men and women.

Alcoholic liver diseases are the most common health condition that alcoholism brings, in particular fatty liver, alcoholic hepatitis, and cirrhosis which later leads to liver cancer.

The good news is a sick liver can be reverted if drinking stops since the liver creates new healthy cells to replace the injured ones. Alcohol rehab is the best option to stop alcohol misuse disorder.

Alcohol poisoning, which happens when a person drinks too much alcohol too quickly, suppresses breathing and heart rate, lowers body temperature, and  causes vomiting and seizures can be lethal.


Methadone is a synthetic opioid commonly used as a substitution therapy for reducing other opioid addictions, such as heroin. This makes methadone an unavoidable evil and most people addicted to it started out using it for heroin rehab. Methadone is also used to relieve moderate to severe pain.

As a treatment for opioid addiction, methadone is only a component of a comprehensive programme that includes counselling and behaviour therapy. Although an opioid, methadone is not as addictive and its effects last long, from 24 to 55 hours, so a single dose is enough for a day. In contrast, heroin’s effects last only a few hours. 

Methadone is a highly regulated drug.(9) But illicit selling still  exists for people who want a potent analgesic for their pain and for users who take the drug to manage withdrawal symptoms. But dosage varies based on several factors and a methadone overdose occurs.

Like other opioids, methadone overdose causes drowsiness and slows down breathing or even leads to unconsciousness. These can result in death.

Few detox options for methadone exist. As methadone withdrawal can be uncomfortable as well as dangerous, seeking private methadone detoxing and rehabilitation is recommended. 


A relatively new drug, Flakka is a chemical variant of the synthetic bath salts, a psychostimulant in the cathinone class known as Alpha-PVP. As potent as methamphetamine but more addictive, Flakka’s origins trace back to South Florida in 2014-2015 and it has since found its way to the UK.

Flakka has extremely intense effects. Like all stimulants, it creates a sense of euphoria. Snorted, smoked, injected, or taken by mouth, it causes paranoid psychosis and hallucinations. It also gives the user extraordinary physical strength and a feeling of invulnerability that leads to bizarre and unsafe behaviour. An effect specific to Flakka is hypoactive delirium, putting the user in a zombie-like status. (10)

Flakka use increased among teens and young adults partly because of its cheap price. The drug produces palpitations, increased blood pressure, and a sustained high temperature that leads to excessive sweating and dehydration. These effects when combined can lead to brain damage, coma or death.

Bath Salts

These designer drugs are not what people put in bathtubs to soak in. They’re highly addictive synthetic cathinones with the street names of Monkey Dust, Vanilla Sky, and Plant Food, to name some. The manufactured cathinone is sold in vials, or small plastic or foil packets mixed with an amphetamine substance such as MDPV, mephedrone or methylone. It comes in white crystalline powder and looks like bath salts, hence the name. The powder is swallowed, smoked, snorted or injected.

Bath salts are psychostimulants that are 10 times more potent than cocaine. (11) Taking them gives the user a long-lasting extreme euphoria, paranoia, increased extroversion and libido, hallucinations and panic attacks. Users under its influence have been known to run into traffic or jump off buildings.

Physical symptoms of bath salts are increased heart rate, high blood pressure and chest pain. They also cause kidney  failure and loss of skeletal muscle that can be lethal. Deaths are often brought on by snorting or injecting the drug.


Drug misuse and dependence can come from legally allowed medication or illicit drugs that have no medical value and are used for recreational purposes only. Overcoming drug abuse is not easy but with the support of family and friends, and professional drug rehab centres, lives can be saved and drug dependents can be productive again.

About the author

Peter Szczepanski

Peter has been on the GPhC register for 29 years. He holds a Clinical Diploma in Advanced Clinical Practice and he is a Clinical Lead in Alcohol and Substance Misuse for Abbeycare Gloucester and works as the Clinical Lead in Alcohol and Substance Use in Worcestershire. Find Peter on Respiratory Academy, Aston University graduates, University of Birmingham, Q, Pharmaceutical Journal, the Dudley Pharmaceutical Committee, Dudley Council, Twitter, and LinkedIn.

Medical Assisted Treatment (MAT)