ketamine treatment is indicated in children and in adults.
As an anaesthetic agent for diagnostic and surgical procedures.
A. ketamine treatment
The use of Ketamine by continuous infusion enables the dose to be titrated more closely, thereby reducing the amount of drug administered compared with intermittent administration. This results in a shorter recovery time and better stability of vital signs.
A solution containing 1 mg/ml of ketamine in dextrose 5% or sodium chloride 0.9% is suitable for administration by infusion.
General Anaesthesia Induction
An infusion corresponding to 0.5 – 2 mg/kg as total induction dose.
Maintenance of anaesthesia
Anaesthesia may be maintained using a microdrip infusion of 10 – 45 microgram/kg/min (approximately 1 – 3 mg/min).
The rate of infusion will depend on the patient’s reaction and response to anaesthesia.
The initial dose of Ketamine administered intravenously may range from 1 mg/kg to 4.5 mg/kg (in terms of ketamine base). The average amount required to produce 5 to 10 minutes of surgical anaesthesia has been 2.0 mg/kg. It is recommended that intravenous administration be accomplished slowly (over a period of 60 seconds). More rapid administration may result in respiratory depression and enhanced pressor response.
Dosage in Obstetrics
In obstetrics, for vaginal delivery or in caesarean section, intravenous doses ranging from 0.2 to 1.0 mg/kg are recommended (see section 4.6 Fertility, pregnancy and lactation).
The initial dose of Ketamine administered intramuscularly may range from 6.5 mg/kg to 13 mg/kg (in terms of ketamine base). A low initial intramuscular dose of 4 mg/kg has been used in diagnostic manoeuvres and procedures not involving intensely painful stimuli. A dose of 10 mg/kg will usually produce 12 to 25 minutes of surgical anaesthesia.
Dosage in Hepatic Insufficiency:
Dose reductions should be considered in patients with cirrhosis or other types of liver impairment. (see section 4.4 Special Warnings and Special Precautions for Use)
Dosage in Obstetrics
Data are lacking for intramuscular injection and maintenance infusion of ketamine in the parturient population, and recommendations cannot be made.
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
Ketamine is contra-indicated in persons in whom an elevation of blood pressure would constitute a serious hazard (see section 4.8 Undesirable effects).
Ketamine should not be used in patients with eclampsia or pre-eclampsia, severe coronary or myocardial disease, cerebrovascular accident or cerebral trauma.
To be used only in hospitals by or under the supervision of experienced medically qualified anaesthetists except under emergency conditions.
As with any general anaesthetic agent, resuscitative equipment should be available and ready for use.
Respiratory depression may occur with overdosage of Ketamine, in which case supportive ventilation should be employed. Mechanical support of respiration is preferred to the administration of analeptics.
The intravenous dose should be administered over a period of 60 seconds. More rapid administration may result in transient respiratory depression or apnoea and enhanced pressor response.
Med. J. 1971, 2: 688), in clinical practice aspiration is seldom a problem.
In surgical procedures involving visceral pain pathways, Ketamine should be supplemented with an agent which obtunds visceral pain.
The psychological manifestations vary in severity between pleasant dream-like states, vivid imagery, hallucinations, nightmares and emergence delirium (often consisting of dissociative or floating sensations). In some cases these states have been accompanied by confusion, excitement, and irrational behaviour which a few patients recall as an unpleasant experience. (See section 4.8 Undesirable Effects).
The median peak rise of blood pressure in clinical studies has ranged from 20 to 25 percent of preanaesthetic values.
Hepatotoxicity has also been reported in patients with extended use (> 3 days).
Drug Abuse and Dependence
Ketamine may potentiate the neuromuscular blocking effects of atracurium and tubocurarine including respiratory depression with apnoea.
Concomitant use of antihypertensive agents and ketamine increases the risk of developing hypotension.
Sympathomimetics (directly or indirectly acting) and vasopressin may enhance the sympathomimetic effects of ketamine.
Concomitant use with ergometrine may lead to an increase in blood pressure.
Coadministration of ketamine with drugs that induce CYP3A4 enzyme may require an increase in ketamine dosage to achieve the desired clinical outcome.
Ketamine crosses the placenta.
.7 Effects on ability to drive and use machines
This medicine can impair cognitive function and can affect a patient’s ability to drive safely.
System Organ Class
|Immune system disorders||Rare||Anaphylactic reaction*|
|Metabolism and nutrition disorders||Uncommon||Anorexia|
|Psychiatric disorders||Common||Hallucination, Abnormal dreams, Nightmare, Confusion, Agitation, Abnormal behaviour|
|Rare||Delirium* Flashback*, Dysphoria*, Insomnia, Disorientation*|
|Nervous system disorders||Common||Nystagmus, Hypertonia, Tonic clonic movements|
|Not Known||Intraocular pressure increased|
|Cardiac disorders||Common||Blood pressure increased, Heart rate increased|
|Respiratory, thoracic and Mediastinal disorders||Common||Respiratory rate increased|
|Uncommon||Respiratory depression, Laryngospasm|
|Rare||Obstructive airway disorder*, Apnoea*|
|Gastrointestinal disorders||Common||Nausea, Vomiting|
|Hepatobiliary disorders||Not known||Liver function test abnormal, Drug-induced liver injury**|
|Skin and subcutaneous tissue disorders||Common||Erythema, Rash morbilliform|
|Renal and urinary disorders||Rare||Cystitis*, Haemorrhagic cystitis*|
|General disorders and administration site conditions||Uncommon||Injection site pain, Injection site rash|
† Common (≥1/100 to <1/10); Uncommon (≥1/1,000 to <1/100); Rare (≥1/10,000 to <1/1,000);
* AE frequency estimated from post-marketing safety database
** Extended period use (> 3 days) or drug abuse
Reporting of suspected adverse reactions
5. Pharmacological properties ketamine treatment
Pharmacotherapeutic group: Other general anesthetics.
ATC Code: N01A X03
5.2 Pharmacokinetic properties
In parturients receiving an intramuscular dose of 250 mg (approximately 4.2 mg/kg), placental transfer rate of ketamine from maternal artery to umbilical vein was 47% at the time of delivery (1.72 versus 0.75 µ g/mL). Average delivery time for these parturients was 12 minutes from the time of ketamine injection to vaginal delivery of a newborn.
Biotransformation takes place in liver. Termination of anaesthetic is partly by redistribution from brain to other tissues and partly by metabolism. CYP3A4 enzyme is the primary enzyme responsible for ketamine N-demethylation to norketamine in human liver microsomes; with CYP2B6 and CYP2C9 enzymes as minor contributors.