Cocaine harms and harm reduction

Cocaine was implicated in almost half of the drug related deaths in 2023. At toxicology, cocaine is often found to be present with other drugs. These other drugs are usually central nervous system depressant (CNSD) drugs such as heroin or methadone. For this reason, naloxone should always be administered when a more typical CNSD overdose presents where cocaine has also been taken. 

The signs and symptoms of a cocaine overdose can be different from those we expect to see in a typical CNSD overdose because cocaine is a stimulant drug.

A cocaine overdose occurs when excessive cocaine intake overwhelms the body causing a life-threatening state. This can result in toxicity, stroke and heart attack.

The mechanism of COSHT involves a complex interaction of pharmacological effects leading to multi-organ dysfunction. This should always be treated as a medical emergency.

• Dopamine and norepinephrine reuptake blockade- This prolongs their duration of action in the synaptic clefts and results in excessive sympathetic nervous system activation (fight-or-flight response), causing tachycardia (fast heart rate), hypertension (high blood pressure), hyperthermia (high body temperature), and agitation.
• Serotonin reuptake blockade- Whilst less prominent an impact than dopamine or norepinephrine, serotonin reuptake inhibition may contribute to CNS excitation and potential neurotoxicity (damage to the brain).
• Sodium Channel Blockade- Cocaine acts as a local anaesthetic by blocking sodium channels in cardiac tissue. This impairs electrical conduction leading to arrhythmias (irregular heart rhythm) or depressed cardiac function.
• Vasoconstriction (the narrowing of blood vessels) and ischemia (sub optimal flow of blood)- This coronary vasoconstriction can precipitate myocardial infarction (heart attack), while cerebral (brain) vasoconstriction increases the risk of stroke.
• Platelet Activation- Cocaine enhances platelet aggregation (the process where tiny blood cells stick together to form a clot or blockage). This increases the likelihood of obstructing blood flow meaning heart attack or stroke become a risk.
• Central Nervous System (CNS) Effects- Overstimulation of the CNS leads to seizures, hyperthermia and agitation. Hyperthermia also exacerbates metabolic demand and can cause muscle breakdown leading to acute kidney damage.

These mechanisms lead to the life-threatening conditions of COSHT such as arrhythmias, heart attack, stroke, seizures, kidney failure, and multi-organ collapse. Rapid medical attention will increase the likelihood of a positive outcome.

• Stroke signs (drooping of the face or loss of movement in the limbs)
• Heart attack signs (pain in chest, arms, jaw, neck)
• High blood pressure (headache, dizziness)
• Increased heart rate (pounding chest, palpitations)
• Severe headache
• Blurring or loss of vision
• Severe agitation, restlessness, confusion, excited delirium*
• Hyperthermia (sweating not caused by heat or exercise)
• Abnormal reflexes/movement
• Seizure
• Diarrhoea, vomiting, abdominal pain

If COSHT is suspected the person should call emergency services as soon as possible and follow the call handler’s instructions.

*Cocaine induced excited delirium. People displaying symptoms such as aggression, hyperactivity, extreme paranoia, hyperthermia, incoherent shouting or screaming and unusual strength are often at risk for sudden death.

Clinical Outcomes

Management within a hospital setting will focus on stabilizing vital signs and may include treatments such as cooling for hyperthermia, benzodiazepines for agitation/seizures and medicating other specific complications.

Reducing the Risk of COSHT

• Taking less cocaine (dose)
• Lengthen the time between doses
• Limit the duration of the sitting
• Not consuming other drugs, alcohol or tobacco within the same sitting
• Accessing heart health checks as a means of identifying cardiovascular problems at the earliest possible stage

Like many other drugs, cocaine can lower inhibitions and make a person more likely to engage in sexual activity. This, often impulsive sex, may reduce the likelihood of barrier contraception use or other safe sex practices.

Rougher sex, such as anal sex, may seem more appealing whilst prolonged sex is common due to the inability to climax. This may lead to the tearing of membranes causing bleeding and increases the potential to transmit blood borne viruses (BBV). 

Men may find it difficult to get and maintain an erection, leading to a frustrated state. 

Overall, there are considerable risk factors associated with cocaine use and sex. Unplanned pregnancies, sexually transmitted infections (STIs), BBV’s and sexual assault are some of the potential negative consequences of having sex under the influence of cocaine.

Longer term cocaine use can change a woman’s menstrual cycle and stop ovulation, whilst damage to the fallopian tubes from STIs can result in infertility.

Cocaine use during pregnancy can cause seizures, migraines, premature birth and in some cases, the placenta can detach from the uterine wall (placental abruption). Stillbirths and miscarriages occur at higher rates in women who use cocaine during pregnancy.

People taking cocaine, especially during binges, often neglect basic self-care. Regular meals, hydration and rest can become secondary to the compulsion to use. Cocaine suppresses appetite, increases energy expenditure and disturbs sleep patterns, all of which can contribute to significant nutritional deficits over time. These effects are especially concerning for people who use heavily or regularly and for those who are already in vulnerable physical health due to homelessness, stress, or poly-substance use.

The combination of cocaine and alcohol is particularly harmful to the body. While alcohol contains calories, it lacks the nutrients needed to maintain health. Alcohol is also a powerful diuretic, meaning it increases fluid loss through urination and contributes directly to dehydration. When people are drinking and using stimulants at the same time, they often do not feel thirsty or may forget to drink water entirely. This significantly increases the risk of becoming dehydrated, especially during all night sessions or binges. The body becomes depleted of not only water, but also vital electrolytes like potassium and sodium, which are essential for heart, kidney, and muscle function.

Cocaine use places considerable stress on the body. Elevated heart rate, increased body temperature, and prolonged periods without rest deplete energy reserves and further dehydrate the system.

Binge use may involve hours or days without food or water, followed by vomiting, diarrhoea, or exhaustion during the crash. These cycles disrupt the body’s ability to absorb nutrients and repair itself, weakening both physical resilience and immune defence. Over time, this increases the risk of infection, slows wound healing, and worsens the impact of other health conditions.

Malnutrition also affects the brain. A lack of essential nutrients such as B vitamins, magnesium, and zinc can worsen mood instability, anxiety and cognitive issues. People experiencing poor nutrition may find it harder to cope with cravings, recover after binges, or regulate their emotions. When combined with sleep deprivation and alcohol related toxicity, these effects can intensify mental health symptoms and increase the likelihood of continued or riskier drug use.

Supporting Better Nutrition and Self Care

Supporting people who use cocaine to maintain even small, manageable routines around eating and drinking can make a real difference. This does not need to mean large meals. Snacks with protein, fruit, or slow release carbohydrates are often more achievable, especially during or after a binge. Encouraging people to keep a bottle of water nearby and take regular sips can reduce dehydration, headaches, and overheating, which are common features of stimulant use.

Before a cocaine session, particularly if use is planned in advance, there is an opportunity to frontload on nutrients and prepare for hydration. Eating a balanced meal beforehand can help reduce the strain on the body, especially if food is unlikely to be consumed during the session itself. Isotonic drinks (such as sports rehydration fluids) are particularly helpful, as they replace both fluids and essential electrolytes that are quickly lost during stimulant use.

This planning stage can also be used to stock up on easy, good quality nutrition. Having ready meals, fruit, protein rich snacks, and hydrating drinks in the fridge or cupboards may make it easier to eat and recover during the comedown phase, when energy is low and the person may not feel like shopping or preparing food. Even small steps like this can improve recovery and reduce longer-term health impacts.

Services and supported accommodations may wish to consider the role that nutrition and hydration play in reducing harm. When there is awareness that cocaine is being used, particularly in binge patterns, staff should reflect on the quality, timing, and availability of meals and fluids. Even small adjustments, such as extending food access hours or providing out of hours nutritious may support recovery and reduce health risks for those using cocaine.