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Can You Overdose on Ketamine?

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Ketamine Overdose

The rapid onset of the effects of ketamine can make it difficult to know how much is too much. There’s a fine line between the extreme high (K-Hole) that some users chase and an overdose which can be fatal. Whether you are prescribed ketamine for pain relief, use it recreationally or have a ketamine addiction, an overdose is a medical emergency. 

This article explains what to do in an overdose situation. It covers:

  • Signs and symptoms of a ketamine overdose
  • Associated health risks 
  • What to do if you think you or someone else has overdosed
  • How a ketamine overdose is treated
  • The dangers of mixing ketamine with other drugs.

Key Facts:

  • A ketamine overdose is a medical emergency. Recognising the signs and symptoms is crucial for seeking timely medical treatment. 
  • Left untreated or with late treatment, a ketamine overdose can result in long-term physical and psychiatric complications or even death.
  • If you think that you or someone else is experiencing a ketamine overdose you should call emergency services for an ambulance and follow these steps. 
  • Treatment for ketamine overdose usually entails treating and monitoring the most acute symptoms in order of priority. The patient may be referred to mental health or substance misuse services for further support. 
  • The majority of ketamine overdoses involve at least one other substance. Mixing ketamine with other drugs increases the risk of long-term complications or death from overdose. 
  • Research statistics indicate that ketamine abuse and overdose are increasing in England, Scotland and Wales. 

Signs, Risks & Symptoms of a Ketamine Overdose

A ketamine overdose is serious. Without early medical intervention, it can result in long-term physical and psychiatric health complications and even fatality, so it’s important to recognise the signs and symptoms. 

What Happens in a Ketamine Overdose?

Due to its dissociative anaesthetic properties, taking small to moderate levels of ketamine can result in sedation and euphoria. Larger doses present the risk of straying into unpredictable and dangerous territory. When levels build up in the bloodstream, the liver struggles to metabolise the drug, and the body begins to shut down.

Signs and Symptoms of Ketamine Overdose

The signs of a ketamine overdose often mirror those of the “high”, albeit to a greater degree. It can be difficult to judge when symptoms become critical, but waiting until the user is unconscious may be too late.

Some common signs and symptoms of ketamine overdose include:

  • Extreme sedation
  • Behaving out of character – angry or agitated
  • Loss of consciousness
  • Hallucinations or paranoia, especially if the user has a pre-existing mental health condition
  • Paralysis
  • Slowed breathing                        
  • Increased blood pressure
  • Fast or irregular heartbeat
  • Confusion
  • Nausea or vomiting
  • Seizures
  • Chest pains

Secondary Issues

Often it’s the secondary issues that put the user in immediate danger. For example, choking as a result of vomiting while unconscious or in a state of paralysis or having a severe accident or injury due to the drug’s anaesthetic properties. 

Long-Term Effects of Ketamine Overdose

The impact of a ketamine overdose often goes beyond the immediate acute symptoms. There can be serious long-term complications that affect the body and mind.

Long-term physical and mental health risks of ketamine overdose include:

  • Cardiac issues – ketamine can increase cardiac output, worsening existing heart problems and even causing cardiac arrest.²
  • Brain damage – the respiratory effects of a ketamine overdose can cause a lack of oxygen to the brain, which may result in permanent brain damage.
  • Ketamine bladder syndrome (ketamine-induced ulcerative cystitis) – irreversible damage to the bladder wall that often results in the organ having to be surgically removed.
  • Liver and kidney damage – the toxic burden of a ketamine overdose can result in liver damage and kidney failure.  The liver and kidneys may already be compromised if there’s a history of ketamine abuse.
  • Anxiety and depression – mental health issues can develop following an overdose, and pre-existing mental health conditions can be exacerbated, particularly when there’s a subsequent period of withdrawal. This is due to disturbances in brain chemistry during habitual use.
  • Long-term dissociation – it’s not unknown for users to remain in a detached state for differing periods after a ketamine overdose. 

If You Think You’re Having (or Witnessing) a Ketamine Overdose

Staying aware of the signs of a potential ketamine addiction and overdose symptoms is essential for getting the right medical treatment. It’s important to act quickly. While death from ketamine overdose is relatively rare, being left with long-term effects, sometimes life-altering in nature, is a real risk. A bigger risk is long-term complications or even death if the user has mixed ketamine with other substances. 

What To Do

If you have any concerns that you or someone else is experiencing a ketamine overdose, follow the following procedures. It may save a life. 

If You Think You May Have Overdosed

  • Try to stay calm
  • Call for emergency services and ask for an ambulance
  • If there is someone with you or nearby, ask them to stay with you
  • Give the emergency services as many details as possible over the phone:
    • What drugs have you taken, and how much?
    • How did you use the drug(s) (injection, by mouth or through the nose)?
    • When did you take the drug(s)?
    • Are you on other prescribed or over-the-counter medications, herbal remedies or supplements?
    • What symptoms are you experiencing?

If You Think Someone Else May Have Overdosed

  • Stay calm, calm the patient and be reassuring
  • Call emergency services and ask for an ambulance
  • Stay with the patient
  • Get as many details from the patient as possible:
    • What drugs have they taken, and how much?
    • How did they use the drug(s) (injection, by mouth or through the nose)?
    • When did they take it?
    • Are they on other prescribed medications, over-the-counter medications, herbal remedies, or supplements?
    • What are their symptoms? (Ask how they feel and describe what you witness.)

If the patient is tense, anxious or panicky:

  • Sit them somewhere quiet and safe away from crowds, loud noises and bright lights.
  • Try to get them to focus on you and tell them to take slow, deep breaths. Remain calm and breathe with them. 

If the patient is extremely drowsy

  • Sit them somewhere quiet and safe and try to keep them awake.
  • If they don’t respond or become unconscious, update the emergency services and place them in the recovery position.
  • Remain calm and don’t do anything that might scare, shock or make them anxious.

If the patient is unconscious or finding it difficult to breathe:

  • Immediately phone for an ambulance if you haven’t done so already.
  • Place them into the recovery position.
  • Stay with them until the ambulance arrives.

When the ambulance arrives:

Give the emergency services crew as many details about the overdose as you can. This is important as it can help them provide the right treatment as quickly as possible. 

Recovery Position

Placing an unconscious or unresponsive person in the recovery position helps them to breathe easily and prevents them from swallowing their tongue or choking if they vomit. 

How to put someone in the recovery position (NHS guidelines):

  • With the person lying on their back, kneel on the floor at their side.
  • Extend the arm nearest you at a right angle to their body with their palm facing up.
  • Take their other arm and fold it so the back of their hand rests on the cheek closest to you, and hold it in place.
  • Use your free hand to bend the person’s knee farthest away from you to a right angle.
  • Carefully roll the person onto their side by pulling on the bent knee towards you.
  • Their bent arm should be supporting the head, and their extended arm will stop you rolling them too far.
  • Make sure their bent leg is at a right angle.
  • Open their airway by gently tilting their head back and lifting their chin, and check that nothing is blocking their airway.
  • Stay with the person and monitor their condition until help arrives.

How Are Ketamine Overdoses Typically Treated?

Despite the prevalence of ketamine addiction, there is currently no available drug explicitly designed to reverse or treat its effects. Treatment usually entails treating and monitoring the most acute symptoms in order of priority. Given ketamine’s effects on cardiac and respiratory functions, monitoring of the heart and breathing take precedence. The nervous system, liver and kidney function may also be affected. Medications may be needed to help counteract panic, anxiety, aggression and hallucinations. Treatment aims to stabilise the patient until the effects have worn off, the hope being that normal function will resume with no long-term damage.

Chronic users are often referred to mental health services or substance misuse services for further support after an overdose. Whether the overdose is accidental or not, this break in the habit is an opportunity to seek treatment for ketamine addiction and any co-existing mental health problems.

Mixing Ketamine With Other Drugs

The majority of ketamine overdose cases involve at least one other substance. Common combinations include cocaine, MDMA, cannabis, alcohol and opioids. Many ketamine overdose-related deaths can be attributed to mixing ketamine with other drugs,  so the dangers can’t be overstated. 

Common risks of mixing ketamine with other drugs include:

  • Respiratory depression and death – when mixed with heroin or prescription opioids such as hydrocodone, oxycodone, and morphine.
  • Heart attack, stroke and other heart complications – when used with stimulants (e.g. cocaine).
  • Intoxication and death – when used with depressants (e.g. alcohol, barbiturates, and benzodiazepines).

Why Do People Mix Ketamine with Other Substances?

There is a range of reasons why a user might knowingly or unknowingly take ketamine alongside other drugs. They include:

  • Using ketamine as a club drug – the user may already be high on another substance when they take ketamine, or they may be experimenting with combining different substances to obtain a better high. 
  • Ketamine withdrawal using another substance to take the edge off ketamine withdrawal.
  • Accidental – taking prescription ketamine with opioids, alcohol or over-the-counter drugs; misjudging the doses needed to get high; or taking street ketamine cut with other unknown substances.
  • Victim of date rape drugging – in a club or dating situation, ketamine may be used to spike a person’s alcoholic drink. The tranquilising and dissociation effects of the drug render the victim unable to consent to sexual intercourse or defend themselves against being raped. 

Ketamine Overdose Statistics

Recent research indicates that ketamine abuse and overdose are on the increase.

  • In 2018, ketamine use was at its highest on record in England and Wales, with 0.8% of adults having taken it. In Scotland, 2.9% of 16-24 year-olds in Scotland had taken ketamine from 2017 to 2018. (source)
  • The number of adults in England entering treatment with ketamine issues rose 27% between 2020 and 2021, nearly three times more than in 2014 – 2015. (source)
  • It’s difficult to estimate the number of overdoses due entirely or partly to ketamine, given users’ propensity to mix substances. But according to research, deaths in England in which ketamine was implicated rose from below 5 p.a in 2005, levelled off at 21 p.a between 2009 and 2016, and increased again to 30 p.a in 2021.(source)

Ketamine Abuse & Addiction

Ketamine is physically and psychologically addictive. The drug’s fast-acting “high” produces effects such as sedation, euphoria, and detachment from reality. With regular use, users develop tolerance to ketamine and have to take increasing amounts to achieve the desired high. If a chronic user stops taking ketamine abruptly, they will experience withdrawal symptoms. Various factors influence whether a user will become addicted, including early life experiences, mental health issues and genetics.

You can recover from ketamine addiction with the right help. We know that admitting you need help is the biggest step, but reaching out for help is also the first step you can take on the road to recovery. Our dedicated admissions staff are waiting to help you or your loved one find their way into recovery from addiction. We handle all enquiries with the strictest confidentiality.


Ketamine Overdose FAQs

Here are answers to a few other questions you may have about the topic of ketamine overdose and drug overdose in general.

What Do You Do If Someone Takes an Overdose (UK)?

If you suspect that someone has taken an overdose or has been poisoned, do not try to treat them yourself. Get medical help immediately. If they do not appear to be seriously ill, call NHS 111 for advice.

Poisoning – NHS

What Happens If You Take Too Much K?

Taking too much ketamine can cause an overdose. Signs of a ketamine overdose include dangerously slow breathing and loss of consciousness. 5 If an overdose is suspected, get immediate medical attention.

K-Hole and the Effects of Ketamine – Verywell Mind

What Happens If You Don’t Get Treatment for an Overdose?

A large overdose can cause a person to stop breathing and die if not treated right away. The person may need to be admitted to the hospital to continue treatment. Depending on the drug, or drugs taken, multiple organs may be affected. This may affect the person’s outcome and chances of survival.

Overdose: MedlinePlus Medical Encyclopaedia

Can You Survive an Overdose?

If a drug overdose does not lead to death, it can lead to serious, long-term consequences. Some people who overdose on drugs and survive have permanent brain damage.

Get in touch today

To find out how we can help you, please telephone Castle Craig on our 24-Hour Helpline: 0808 271 7500. or click here to arrange a free addiction assessment or here for more information.

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