Ketamine (A complete review)

Ketamine is a medication used to initiate and maintain anesthesia during surgery.

It induces a trance-like state and also provides pain relief, feelings of sedation, and loss of memory. 

What is ketamine?

Ketamine has a long history of being abused as a club drug. It is also used as an anesthetic and analgesic, or pain killer.

Today, however, it might be one of the biggest breakthroughs in treating severe depression. 

Ketamine is being hailed as a breakthrough treatment for severe depression

Norco is another drug used to relive pain.

How does ketamine work?

Ketamine works like a flash mob, temporarily taking over a certain chemical ‘receptor’.

In some cases and with expert medical care, that can be a good thing, but without suitable medical assistance from a health care professional it can be bad news. 

What are common side effects of ketamine? 

There are several serious side effects of ketamine that need to be treated immediately.

These include: 

·      bloody or cloudy urine

·      problems passing urine

·      feeling frequent urges to urinate 

·      blurred vision

·      tightness, pain or discomfort in the chest

·      difficulty breathing, shortness of breath, or not breathing at all

·      convulsions

·      dizziness, lightheadedness or fainting

·      irregular heartbeat, either too fast or too slow

·      skin problems such as itching or rash

·      delusions or confusion

·      signs of an allergic reaction such as puffy or swollen eyelids, face, lips or tongue

·      feeling overexcited, nervous or restless

·      unusual fatigue or weakness.

How can ketamine be misused? 

At lower doses, it can help ease pain.

Ketamine helps sedatives work and may help people need fewer addictive painkillers, like morphine after surgery or while caring for burns.

When misused, ketamine can change your sense of sight and sound.

You can have hallucinations and feel out of touch with your surroundings — and even from yourself.

It can make it hard to speak or move. It has also been abused as a date-rape drug.

When people use ketamine recreationally at high doses, they can feel like they are in a “K-hole”.

This indicates that they are close to becoming unconscious.

If someone you know is in this state, seek emergency medical care immediately. 

Is ketamine an approved treatment for depression? 

A ketamine-like drug esketamine, in nasal spray form, became a licensed treatment for depression in the UK in 2019.

It was previously used in depression as ‘off-label’ treatment. Ketamine is also licensed as an anaesthetic and for analgesia.

In the US, the FDA approved a nasal spray ketamine for treatment-resistant depression, available only at a certified doctor’s clinic, in March 2019.

Patients with major depressive disorder who, despite trying at least two antidepressant treatments given at adequate doses for an adequate duration in the current episode, have not responded to treatment are considered to have treatment-resistant depression.

These are the candidates for ketamine treatment.

Ketamine is mostly directed at depressed patients who are treatment resistant.

Researchers have, for the last 15 years, been testing whether ketamine can improve symptoms of depression in patients who have not responded to other treatments or in patients who are hospitalized for suicidality. 

In these studies, patients are administered ketamine intravenously (IV) or via a nasal mist once a week.

Ketamine administration is carried out in a clinic under very strict medical supervision.

In some patients, symptoms of depression are resolved in just a few hours. 

Ketamine can also distort the senses of sight and touch in some patients.

The ultimate goal is to find a dose that is large enough to relieve symptoms of depression, but small enough to avoid unpleasant side effects. 

How quickly does ketamine work?

For some people, ketamine can work within a few hours. For other people it may take a few treatments before their depression improves.

It is not possible to tell who will respond, or how quickly, to ketamine.

It is thought that if you do not respond to three treatments of ketamine you are unlikely to see a benefit from any further treatment.

Is ketamine addictive?

Ketamine is sometimes taken illegally in large, frequent doses. Drug abusers can become addicted to it.

Sometimes people find that if they stop ketamine their depression relapses. This is not the same as addiction. This is reliance.

Sometimes patients taking it for depression find that their depression is no longer controlled despite continuing to have treatment with ketamine.

There can be several possible reasons, one of which is that they have developed tolerance to ketamine.

This may mean that a treatment break is needed or that it is no longer an effective treatment and therefore will be stopped.

Sometimes, the dose can be safely increased. However, it is best to reduce the dose or extend the interval between doses to help maintain the effect.

Major depressive disorder (MDD) is a mood disorder that causes feelings of worthlessness.

Sometimes, people find that they think a lot about ketamine and crave it.

It is important to notice that this is happening and to be open and honest with your medical professional about this.

It is not reported that anyone who has taken ketamine as prescribed for the treatment of depression has become addicted.

However, when people use ketamine illegally, it is not uncommon for the dose and frequency to escalate.

For comparison, ketamine is much less addictive and dangerous than strong opiates (eg fentanyl, methadone), is probably less addictive and dangerous than tobacco, and has equivalent risks to benzodiazepines.

What is the difference between ketamine and other antidepressants?

Selective serotonin reuptake inhibitors (SSRIs) typically take several weeks before patients start to feel a noticeable improvement.

Ketamine differs in that it relieves symptoms of depression as it leaves your body within a few hours. 

Researchers theorize that ketamine allows certain connections between neurons to regrow, and that these neurons are heavily involved in regulating mood. 

Major depressive disorder (MDD) is a mood disorder that causes feelings of worthlessness and loss of interest in daily activities.

Common symptoms of MDD are as follows: 

·      chronic feelings of sadness, tearfulness, emptiness or hopelessness

·      loss of interest in activities that once used to bring enjoyment (e.g. sex, hobbies) 

·      outbursts of anger 

·      irritability 

·      frustration 

·      issues with sleeping too much or insomnia

·      lack of energy and fatigue 

·      changes in eating patterns and weight (i.e., increased appetite and weight gain or reduced appetite and weight loss)

·      anxiety

·      agitation

·      restlessness

·      slowed speaking, thinking and movement 

·      feelings of worthlessness 

·      dwelling on past failures

·      feelings of guilt 

·      trouble concentrating, making proper decisions and remembering things 

·      physical problems such as back pain or headaches that cannot be explained by another medical condition.

Frequently asked questions (FAQs) about ketamine:

1.    What is ketamine used for?

It is used for patients with severe depression who have not responded to any other treatments.

2.    Is ketamine addictive?

It’s possible to get addicted or need higher doses to feel the effects (this is less likely to happen when you get ketamine for medical reasons).

An overdose can be deadly.

3.    Can I drink alcohol if I am receiving ketamine?

You must not drink alcohol on the night before and day you take ketamine and for 24 hours afterwards.

If possible, you should avoid drinking alcohol completely while you are taking ketamine.

This is because alcohol may reduce the benefit and increase some of the side-effects of ketamine.

4.    Can I drive if I am receiving ketamine?

You should not drive until the morning after you have had ketamine treatment.

However, when you first start taking ketamine or when your dose is increased you may feel drowsy the next day.

You should use common sense and not drive if you feel drowsy.

5.    Can I take other medication with ketamine?

Benzodiazepines (such as Diazepam, Lorazepam, Clonazepam and Temazepam), morphine and the epilepsy drug lamotrigine are thought to interact with ketamine so it is advised that these are not taken the night before or the day you have ketamine.

Other than those listed above, ketamine should not affect your other medicines. 

Other painkillers including opioids (e.g. codeine), non steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, or paracetamol can be taken at the same time as ketamine.

6.    What is the usual dosage of ketamine?

The dose of ketamine you are prescribed is decided by your medical or health care professional.

Doses are calculated on your weight at 0.5mg/kg and should be reviewed before each treatment.

For most people this dose will not change.

However, doses may be increased or decreased during the treatment period.

7.    How does ketamine work?

The drug is thought to work on a different brain pathway from that used by the most commonly used antidepressant drugs, known as selective serotonin reuptake inhibitors (SSRIs).

These work by stopping the brain mopping up the chemical serotonin.

Ketamine and esketamine appear to act on a different brain chemical called glutamate, and in animal studies has been shown to restore connections between brain cells that are thought to shrink back during prolonged periods of depression.

8.    How quickly does ketamine work?

An injection gives a very quick response, with effects occurring in one to five minutes.

Oral consumption requires between five and 30 minutes.

9.    What are the common side effects of ketamine?

·       feelings of calmness and relaxation

·       relief from pain

·       depressed mental state

·       dizziness

·       detached feeling from body

·       slurred speech

·       diminished reflexes

·       hallucinations lasting from half an hour to an hour

·       nystagmus (repetitive, uncontrolled movements of the eyes)

High doses may dangerously reduce breathing, lead to muscles spasms or weakness, dizziness, balance difficulty, impaired vision, slurred speech, nausea and vomiting or severe confusion.

10.         What else is ketamine used for?

Ketamine has been used as an anaesthetic drug since the 1960s.

At lower doses, it can help ease pain. Ketamine helps sedatives work and may help people need fewer addictive painkillers, similar to morphine after surgery or while caring for burns.

To get more insight into depression, click here. 

For more information on ketamine here is some reading material:

Ketamine Infusions: A Patient’s Guide: Everything you need to know before going for Ketamine infusions.


This book will guide you through everything you need, from choosing your medical provider, to what to expect during your infusion experience, and how to get the best results from your infusions.

This book was written with the input of physicians and patients from around the world and was accumulated with data amassed over the last 20 years.

Ketamine for Depression


This book summarises the research that has been carried out into ketamine for the treatment of depression over the past 15 years and, most importantly, describes different ways of using ketamine that are both practical and cost–effective.

Ketamine for Treatment-Resistant Depression: The First Decade of Progress


This book brings together an international group of clinicians and researchers from a broad swath of inter-related disciplines to offer the most up-to-date information about clinical and preclinical research into ketamine and second-generation “ketamine-like” fast-acting antidepressants.


What You Need to Know About Ketamine’s Effects. WebMD. February 2018

FDA approves new nasal spray medication for treatment-resistant depression FDA – March 2019

Ketamine treatment service – NHS UK – January 2020 

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