Anaesthetic 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 reported at maternal IV doses >=1.5 mg/kg). Not recommended during lactation.

Ketamine

Brand names: Ketalar

Ketamine is a dissociative anaesthetic used in emergency and prehospital care for procedural sedation, induction of anaesthesia and analgesia, valued for preserving airway reflexes and cardiovascular stability.

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: IV induction 1-4.5 mg/kg (average 2 mg/kg produces 5-10 minutes of surgical anaesthesia); IM induction 6.5-13 mg/kg (10 mg/kg gives about 12-25 minutes). All doses in terms of ketamine base

Route: Slow IV injection (over 60 seconds), IM injection, or IV infusion

Frequency: Single induction dose; maintain with additional doses of one-half to the full induction dose, or by infusion, as needed

IV infusion: induction 0.5-2 mg/kg total; maintenance by microdrip 10-45 micrograms/kg/min (~1-3 mg/min), titrated to response — a 1 mg/ml solution in glucose 5% or sodium chloride 0.9% is suitable. Give IV slowly over 60 seconds; rapid injection risks respiratory depression/apnoea and an enhanced pressor response. A low IM dose of 4 mg/kg has been used for diagnostic procedures not involving intense pain. Obstetrics (vaginal delivery or caesarean section): IV 0.2-1.0 mg/kg. Premedicate with an anticholinergic (e.g. atropine, hyoscine, glycopyrronium) to reduce hypersalivation; a benzodiazepine (midazolam, diazepam, lorazepam) reduces emergence reactions. Consider dose reduction in hepatic impairment (cirrhosis). The UK SPC doses adults, elderly and children on the same per-kg basis. For hospital use by or under the supervision of experienced anaesthetists (except in emergencies).

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.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Conditions where an 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
Nystagmus, hypertonia, tonic-clonic movements
Increased blood pressure and heart rate
Nausea and vomiting
Diplopia; raised intraocular pressure

Interactions

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

Clinical monograph

How it works

It is principally an NMDA-receptor antagonist, producing a dissociative state with analgesia and amnesia while tending to maintain airway tone, respiratory drive and sympathetic-mediated cardiovascular support.

Prescribing in practice

It typically raises blood pressure and heart rate through sympathetic stimulation, so use with caution where this is hazardous, such as severe uncontrolled hypertension.
Emergence phenomena such as vivid dreams, agitation and hallucinations can occur and are reduced by a calm environment and co-administered benzodiazepines.
It increases salivation and laryngeal reflexes, and laryngospasm can occur, so airway and suction equipment must be ready.

Monitoring

Monitor airway, oxygen saturation, blood pressure, heart rate and conscious level throughout sedation and recovery.

Counselling the patient

This medicine produces a dream-like state and strong pain relief during the procedure.
You may experience vivid dreams or odd sensations as it wears off.
Do not drive or make important decisions for the rest of the day.

Evidence & guidelines

Ketamine is an established agent for emergency procedural sedation and prehospital analgesia and anaesthesia.

Reference: NICE; DAS RSI Guidelines 2015; Annals EM Ketamine Review 2019; 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

📚 MRCEM Revision

Featured in these MRCEM clinical pathways

Ketamine is a core drug in the following exam-focused workups on our sister siteReviseMRCEM.

MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.