Dissociative Anaesthetic (NMDA Receptor Antagonist) Pregnancy: Use in pregnancy not established and not recommended, except during surgery for abdominal (caesarean) or vaginal delivery; ketamine crosses the placenta. Neonatal respiratory depression and low Apgar scores reported at maternal IV doses >= 1.5 mg/kg. Use during lactation not established and not recommended.

Ketamine (Anaesthesia/Sedation)

Brand names: Ketalar

Ketamine is a dissociative anaesthetic used for anaesthesia and procedural sedation, and at lower doses for analgesia; it is valued where airway reflexes and blood pressure need to be preserved (e.g. trauma, asthma).

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 1 to 4.5 mg/kg by slow intravenous injection (over 60 seconds); average 2 mg/kg produces 5-10 minutes of surgical anaesthesia within ~30 seconds

Route: Intravenous (IV) injection; also IV infusion and intramuscular (IM)

Frequency: Single induction dose titrated to response; maintenance by repeat increments of half to the full induction dose as needed

All doses expressed in terms of ketamine base; titrate to the patient's requirement. IM induction 6.5-13 mg/kg (a 10 mg/kg dose usually gives 12-25 minutes of surgical anaesthesia within 3-4 minutes). IV infusion: total induction dose 0.5-2 mg/kg; maintenance by microdrip 10-45 microgram/kg/min (approximately 1-3 mg/min) using a 1 mg/ml solution in dextrose 5% or sodium chloride 0.9%. Obstetrics (vaginal delivery or caesarean section): IV 0.2-1.0 mg/kg. Consider dose reduction in cirrhosis or other hepatic impairment. The SPC groups adults, elderly (over 65 years) and children under the same weight-based dosing; use only in hospital by or under the supervision of experienced anaesthetists.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

See Full Prescribing Information for important dosage and administration instructions. ( 2 ) Induction of anesthesia: -- Intravenous route : Initially, 1 to 4.5 mg/kg administered slowly (over a period of 60 seconds). Alternatively, administer a dose of 1 to 2 mg/kg at a rate of 0.5 mg/kg/min. ( 2.2 ) -- Intramuscular route : Initially, 6.5 to 13 mg/kg. ( 2.2 ) Maintenance of anesthesia: Increments of one-half to the full induction dose may be repeated as needed ( 2.2 ). Adjust the dose according to the patient's anesthetic needs and whether an additional anesthetic agent is employed. ( 2.2 ) Supplement to other anesthetic agents : The regimen of a reduced dose of KETALAR supplemented with …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-03-27. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to ketamine or any excipient
Conditions in which a significant elevation of blood pressure would constitute a serious hazard
Eclampsia or pre-eclampsia
Severe coronary or myocardial disease
Cerebrovascular accident or cerebral trauma

Side effects

Emergence reactions - hallucinations, abnormal dreams, nightmares, confusion, agitation, abnormal behaviour (common)
Nystagmus, hypertonia, tonic-clonic movements (common)
Increased blood pressure and increased heart rate (common)
Increased respiratory rate; respiratory depression and laryngospasm (uncommon)
Nausea and vomiting (common)

Interactions

Theophylline or aminophylline - may lower the seizure threshold; consider an alternative (from US labelling)
Sympathomimetics and vasopressin - may enhance sympathomimetic effects; monitor vital signs (from US labelling)
Benzodiazepines, opioid analgesics or other CNS depressants (including alcohol) - may cause profound sedation, respiratory depression, coma or death; opioids may prolong recovery (from US labelling)

Clinical monograph

How it works

It is mainly an NMDA-receptor antagonist, producing dissociative anaesthesia with relative preservation of airway tone and respiration, bronchodilation and sympathetic stimulation.

Prescribing in practice

It tends to maintain or raise blood pressure and causes bronchodilation, useful in shock or severe asthma.
Emergence phenomena (vivid dreams, hallucinations, agitation) occur — a quiet recovery and a benzodiazepine can help; it increases secretions.
It is a controlled drug with recognised misuse potential.

Monitoring

Monitor conscious level, airway, oxygenation, heart rate and blood pressure; observe during emergence.

Counselling the patient

You may feel detached or have vivid dreams as it wears off.
Do not drive or make important decisions for the rest of the day.

Evidence & guidelines

Used for anaesthesia/procedural sedation and analgesia, particularly where haemodynamic stability or bronchodilation is wanted.

Reference: Miller's Anaesthesia; WHO Model List of Essential Medicines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways