Ketamine is an anaesthetic and painkiller used in hospitals, ambulances and operating theatres. It induces anaesthesia, provides strong pain relief, and is increasingly used under specialist supervision for treatment-resistant depression. It is a Schedule 6 medicine given by trained clinicians, not something to obtain or use independently.
What is Ketamine?
Ketamine is a dissociative anaesthetic, given by injection or infusion. In South Africa it is a Schedule 6 medicine — the most tightly controlled category short of prohibited substances — and it is administered by anaesthetists, emergency clinicians and paramedics rather than dispensed for home use.
It works mainly by blocking NMDA receptors, which carry glutamate signalling in the brain. Most anaesthetics work by enhancing GABA, the brain’s inhibitory signal; ketamine instead interrupts an excitatory one. The result is a state described as “dissociative” — the person is unresponsive to pain and detached from their surroundings rather than simply asleep.
That different mechanism gives ketamine a property no other anaesthetic has: it maintains blood pressure and breathing rather than suppressing them. Most anaesthetics drop blood pressure and depress respiration, which is dangerous in someone already shocked or bleeding. Ketamine largely does not, which makes it invaluable in trauma, in emergencies, and in settings without full anaesthetic support.
The same NMDA action is the basis of its use in depression, discussed below.
What is Ketamine commonly used for?
Anaesthesia and emergency medicine:
- Induction and maintenance of general anaesthesia, particularly in trauma, shock or major blood loss.
- Procedural sedation — reducing a dislocated joint, setting a fracture, dressing a burn.
- Anaesthesia in resource-limited settings, where it can be used safely without a ventilator.
- Paediatric procedures, where it is widely used.
- Pain relief by paramedics at the scene of an injury.
Pain management:
- Severe acute pain, including after major surgery.
- Chronic and neuropathic pain resistant to other treatment, at low doses in specialist pain clinics.
- Cancer pain, in some circumstances.
Mental health, under specialist supervision:
- Treatment-resistant depression, where several antidepressants have failed.
- Depression with acute suicidal thoughts, where its speed matters.
The mental health use is what most people are now searching about, and it deserves accuracy.
Conventional antidepressants such as amitriptyline or an SSRI take weeks to work. Ketamine, acting on a completely different system, can lift severe depressive symptoms within hours — a genuinely significant finding, and the reason it has become a serious area of psychiatric research and practice.
But the qualifications are substantial, and they matter:
- The effect is short-lived, typically days to a couple of weeks, so it is given as a supervised course rather than once.
- It is for treatment-resistant depression, not a first option.
- It is given in a monitored clinical setting, with blood pressure and mental state observed.
- It does not replace therapy or ongoing treatment — it is used to create a window in which other treatment can work.
How Ketamine fits into this medicine category
| Group | Examples | Role |
|---|---|---|
| Dissociative anaesthetics | Ketamine | Anaesthesia, emergency sedation, severe pain, resistant depression |
| Other anaesthetics | Propofol, thiopentone | General anaesthesia; suppress blood pressure and breathing |
| Opioids | Morphine, tramadol | Moderate to severe pain |
| Antidepressants | SSRIs, amitriptyline (Trepiline) | First-line depression treatment; take weeks |
| Anticonvulsants | Pregabalin (Nurika) | Nerve pain, epilepsy |
See the mental health and neurology medicines hub.
What to check before using Ketamine
Ketamine is given by a trained clinician in a monitored setting. There is nothing for a patient to take at home, and this page does not describe self-administration.
If you are having a procedure under ketamine, tell the clinical team if you:
- Have high blood pressure, heart disease, or a history of stroke — ketamine raises blood pressure and heart rate.
- Have raised pressure in the eye (glaucoma) or a recent eye injury.
- Have a history of psychosis, schizophrenia or bipolar disorder — ketamine can precipitate or worsen psychotic symptoms.
- Have liver disease.
- Are pregnant or breastfeeding.
- Have a history of substance use, including previous ketamine use.
- Take any other medicines, including for mental health.
Expect a recovery period. Emergence from ketamine can involve vivid dreams, hallucinations, confusion or distress — more common in adults than children. Clinical teams manage this by recovering people in a calm, quiet environment and sometimes giving a benzodiazepine alongside. Being told what to expect beforehand reduces how distressing it is.
Do not drive or make important decisions for at least 24 hours afterwards, and arrange for someone to take you home.
Possible cautions and when to ask a pharmacist or doctor
Ketamine obtained outside medical care is genuinely dangerous. It is misused recreationally, and that carries risks the clinical use does not: unknown purity and dose, accidents and injury while dissociated, choking on vomit while unresponsive, and — with repeated heavy use — severe and sometimes irreversible bladder damage requiring surgery, along with abdominal pain and cognitive impairment. Dependence develops. If you or someone you know is using ketamine outside medical supervision, that is worth raising with a doctor, and help is available without judgement.
For depression, use an established service. Ketamine clinics vary considerably in standards. A legitimate service assesses you properly, treats in a monitored setting, involves a psychiatrist, and provides ongoing care rather than infusions alone. Be cautious of anywhere offering it without assessment or follow-up.
During and after clinical use, expect possible nausea, raised blood pressure, blurred or double vision, and disorientation.
It is not a cure for depression. It can open a window of relief; the sustained work is done by therapy, ongoing medication and support.
Seek urgent medical attention for chest pain or palpitations, severe confusion or agitation that does not settle, difficulty passing urine or blood in the urine, severe abdominal pain, hallucinations persisting after recovery, or thoughts of self-harm.
If you are struggling with your mental health, contact your doctor, a clinic, or the South African Depression and Anxiety Group (SADAG) — support is available, and treatment-resistant depression is treatable.
Related medicine guides
Frequently asked questions
What is ketamine used for? Anaesthesia and procedural sedation, severe and chronic pain, and — under specialist supervision — treatment-resistant depression.
Why is it used in emergencies and trauma? Unlike most anaesthetics, ketamine maintains blood pressure and breathing rather than suppressing them, which matters greatly in someone shocked or bleeding.
Does it really treat depression? It can relieve severe depressive symptoms within hours, which conventional antidepressants cannot. The effect is short-lived, it is used for treatment-resistant depression, and it is given in monitored settings alongside ongoing care.
Can I get it for depression in South Africa? Only through a legitimate clinical service, following proper psychiatric assessment. It is a Schedule 6 medicine and cannot be obtained or self-administered.
Is it addictive? Dependence develops with repeated non-medical use, and heavy use causes serious, sometimes irreversible bladder damage.
Will I hallucinate during a procedure? Vivid dreams, hallucinations or disorientation can occur during recovery. Clinical teams anticipate and manage this, and knowing to expect it makes it far less distressing.