Ketamine information from DrugsUpdate  

Pharmacodynamics

Pharmacokinetics

Ketamine has a direct action on the cortex and limbic system. It produces a cataleptic-like state wherein the patient is withdrawn from the surrounding environment.

Distribution Crosses the placenta.

MetabolismHepatic biotransformation to norketamine. Other metabolic pathways include hydroxylation of the cyclohexone ring and conjugation with glucuronic acid.

Excretion Via urine (as metabolites); 2.5 hr (beta phase half-life).

Ketamine Indications / Ketamine Uses

Information Not Available

Ketamine Adverse Reactions / Ketamine Side Effects

Emergence reactions e.g. vivid dreams, hallucinations, confusion, irrational behaviour. Increased muscle tone sometimes resembling seizures. Temporary hypertension and tachycardia. Hypotension, bradycardia, arrhythmias. Respiratory depression, apnoea, laryngospasm, diplopia, nystagmus, nausea, vomiting, lachrymation, hypersalivation, raised intraocular and CSF pressure, skin rash and pain at inj site.

Precautions

Information Not Available

Special Precautions

Minimise verbal and tactile stimulation during recovery period. Chronic alcoholic and alcohol-intoxicated patients. Preanaesthetic elevated CSF pressure. Dependence and tolerance may develop. May impair ability to drive or operate machinery. Monitor cardiac function in patients with hypertension or cardiac decompensation. Pregnancy and lactation.

Other Drug Interactions

May increase effects of nondepolarising muscle relaxants. May reduce hypnotic effect of thiopental. Prolonged recovery time with barbiturates/narcotics. Reduced cardiac output, BP and pulse rate with halothane. Increased risk of hypertension and tachycardia with thyroid hormones. Seizures and tachycardia may occur when used with theophyllines.

Other Interactions

Information Not Available

Dosage

Intravenous Induction of anaesthesia Adult: 1-4.5 mg/kg as IV inj. Surgical anaesthesia is produced within 30 sec of the end of inj. Usual dose to produce 5-10 minutes of anaesthesia: 2 mg/kg over 60 seconds. Alternatively, 1-2 mg/kg infused at 0.5 mg/kg/minute; may use with diazepam to prevent emergence reactions. Child: 1-4.5 mg/kg as IV Inj. Surgical anaesthesia is produced within 30 sec of the end of inj and lasts for 5-10 min if 2 mg/kg is given over 60 sec. Alternatively, 0.5-2 mg/kg as IV infusion. Maintenance: Achieve with 10-45 mcg/kg/min; titrate infusion rate according to response. Intramuscular Induction of anaesthesia Adult: 6.5-13 mg/kg. Usual dose to produce 12-25 minutes of anesthesia: 10 mg/kg. Incompatibility May form precipitates with barbiturates; do not inject in the same syringe.

Food(before/after)

Information Not Available

Ketamine and Pregnancy

Caution when used during pregnancy. Category B: Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).

Ketamine and Lactation

Caution when used during lactation

Ketamine and Children

Information Not Available

Ketamine and Geriatic

Information Not Available

Ketamine and Other Contraindications

Hypertension, history of cerebrovascular accident. Eye injury, raised ocular and intracranial pressure. Psychotic disorders.

Storage

Intramuscular Store at 15-30 ℃ (59-86 ° F). Intravenous: Store at 15-30 ℃ (59-86 ° F).

Lab interference

Intramuscular Store at 15-30 ℃ (59-86 ° F). Intravenous: Store at 15-30 ℃ (59-86 ° F).