Ketamine
Ketamine: instructions for use and reviews
- 1. Release form and composition
- 2. Pharmacological properties
- 3. Indications for use
- 4. Contraindications
- 5. Method of application and dosage
- 6. Side effects
- 7. Overdose
- 8. Special instructions
- 9. Application during pregnancy and lactation
- 10. In case of impaired renal function
- 11. Drug interactions
- 12. Analogs
- 13. Terms and conditions of storage
- 14. Terms of dispensing from pharmacies
- 15. Reviews
- 16. Price in pharmacies
Latin name: Ketamine
ATX code: N01AX03
Active ingredient: ketamine (Ketamine)
Manufacturer: Moscow Endocrine Plant (Russia)
Description and photo updated: 2019-27-08
Ketamine is a drug for non-inhalation general anesthesia.
Release form and composition
Dosage form - solution for intramuscular (i / m) and intravenous (i / v) administration: colorless or weakly colored transparent liquid (2 ml and 5 ml in ampoules or 5 ml in vials, 5 pcs. In a blister strip packaging, in a cardboard box 1 or 2 packages and instructions for the use of Ketamine).
The active ingredient is ketamine hydrochloride, in 1 ml of a solution of 57.6 mg, which is equivalent to 50 mg of ketamine.
Auxiliary components: sodium chloride, benzethonium chloride, water for injection.
Pharmacological properties
Pharmacodynamics
The use of ketamine causes dissociative anesthesia, which is characterized by excitation of some parts of the brain and oppression of others. This explains the analgesic effect against the background of incomplete suppression of consciousness, and the preservation of spontaneous breathing, cough, laryngeal and pharyngeal reflexes (the dose of ketamine, which causes apnea, is 8 times higher than the hypnotic dose). In the process of using the substance, the surgical stage of general anesthesia does not develop (the visceral analgesic activity is insufficient, which must be taken into account when performing abdominal operations).
Ketamine causes a specific set of symptoms. These include somatic analgesia, a condition that resembles neuroleptanalgesia, increased blood pressure, myocardial contractility, minute blood volume and myocardial oxygen demand, relaxation of bronchial smooth muscles. The tone of skeletal muscles practically does not decrease, it can lead to involuntary muscle twitching.
The minimum dose of ketamine in adults, which causes a hypnotic effect with a single intravenous injection, is 0.5 mg / kg of body weight (the duration of depression of consciousness is 1.5 minutes). When a dose is administered at the rate of 1 mg / kg, consciousness is inhibited for 6 minutes, 1.5 mg / kg for 9 minutes, 2 mg / kg for 10-15 minutes. When ketamine is administered intramuscularly at a dose of 4–8 mg / kg, the effect develops in 2–4 minutes (6–8 minutes), its average duration is 12–25 minutes (up to 30–40 minutes).
When administered intramuscularly in children, general anesthesia occurs in 2–6 minutes, when administered intravenously, in 15–60 seconds; the duration of the effect is 15-30 and 5-15 minutes, respectively.
During the recovery of consciousness, the patient has drowsiness, which is often accompanied by reactions in the form of delirium, hallucinations, vivid figurative dreams. After waking up, sometimes for 6-8 hours, disorientation may persist. The severity and frequency of these reactions, as well as the cardiac stimulating effect, decreases with the combined use of ketamine with neuroleptics (antipsychotics) and tranquilizers (anxiolytics) - diazepam, droperidol.
In case of somatic pain, the analgesic effect of ketamine is manifested in the case of administration of sub-drug doses. The maximum analgesic effect is observed 10 minutes after injection into a vein, the duration of action is 2-3 hours; with intramuscular administration, a more lasting effect is observed.
Pharmacokinetics
Ketamine is highly soluble in fats. Due to this, its rapid penetration into the central nervous system occurs. The substance easily penetrates the histohematogenous barriers, including the blood-brain barrier, which also stimulates blood circulation. Binds to plasma proteins at a level of 12%.
The volume of distribution of the substance is in the range from 1.8 to 2 l / kg, T 1/2 (half-life) is 2-3 hours. Most of the metabolic products are excreted in the urine for 2 hours. The main reason for the termination of the central action of ketamine is its rapid redistribution from the brain to other tissues.
Biotransformation of the substance is carried out by demethylation by hepatic microsomal enzymes. In the process, several metabolites are formed, some of them retain from 1/5 to 1/3 of the anesthetic activity of ketamine. Elimination of the substance is determined by the system of smooth endoplasmic reticulum oxidases. Norketamine - the main metabolite, has some hypnotic activity, which is weaker than that of ketamine. Ketamine and norketamine in the process of further metabolism are converted into hydroxylated derivatives, which then form conjugates with glucuronic acid and are excreted from the body.
Metabolites in small amounts can remain in the body for several days; with repeated administration, cumulation is not observed. If repeated anesthesia has been administered, ketamine tolerance may develop, due in part to the induction of liver enzymes.
Indications for use
- Basic and introductory general anesthesia (especially if it is necessary to preserve spontaneous breathing in patients or in patients with low blood pressure, as well as during operations with artificial ventilation of the lungs with breathing mixtures that do not include dinitrogen oxide (nitrous oxide));
- Anesthesia for emergency surgical interventions, including situations during the evacuation of patients with blood loss and traumatic shock;
- As part of multicomponent intravenous anesthesia for various surgical procedures;
- Pain relief during cardiac catheterization, endoscopy and other diagnostic procedures;
- Minor surgical procedures when dressing burns and other lesions.
Contraindications
- Myocardial infarction (including the period of the last 6 months);
- Arterial hypertension and other pathologies for which an increase in blood pressure is contraindicated;
- Angina pectoris;
- Severe renal impairment;
- Violation of cerebral circulation (including a history);
- Epilepsy and other diseases occurring with convulsive activity;
- Alcoholism;
- Preeclampsia and eclampsia;
- The period of pregnancy and breastfeeding;
- Hypersensitivity to drug components.
Ketamine anesthesia is used with caution in decompensated chronic heart failure, pharyngeal or laryngeal surgery.
Ketamine, instructions for use: method and dosage
Ketamine in ampoules and vials is used by intravenous fractional, single-stage jet, drip or intramuscular injection.
For adults, the dose of the drug is prescribed at the rate of 2-3 mg for i / v or 4-8 mg per 1 kg of patient weight with i / m administration.
The recommended dosage for maintaining anesthesia with intravenous administration is 0.5-1 mg or with intramuscular injection - 3 mg per 1 kg of body weight. The intravenous drug can be administered drip using an infusion pump at a rate of 2 mg per 1 kg per hour or an infusion system with the introduction of a 0.1% ketamine solution prepared with 5% dextrose (glucose) solution or 0.9% sodium chloride solution, the infusion rate is 20-50 drops per minute.
In children, introductory anesthesia for combined anesthesia is carried out after appropriate premedication by a single intramuscular injection of a dose of the drug at the rate of 4-5 mg per 1 kg of the child's weight in the form of a 5% solution.
With basic anesthesia, ketamine is administered intramuscularly in the form of a 5% solution or intravenously at a dose of 2-3 mg per 1 kg of body weight - simultaneously jet (1% solution) or drip (0.1% solution) at a rate of 50 -60 drops per minute.
Dosage for IM administration depends on the age and weight of the child:
- Infants under 1 year old - at the rate of 8-12 mg per 1 kg;
- Children 1-6 years old - 6-10 mg per 1 kg;
- Teenagers 7-14 years old - 4-8 mg per 1 kg.
General anesthesia is maintained by repeated injections of the drug at a dose: i / m - at the rate of 3-5 mg per 1 kg or i / v (jet or drip) - 0.5-1 mg per 1 kg, infusion rate 0.1% solution of the drug 30-60 drops per minute.
The effect of ketamine is increased by a combination with antipsychotics (droperidol) and fentanyl, promedol and other analgesics; with this combination, it is recommended to reduce the dose of the drug.
Side effects
The use of Ketamine can cause side effects:
- From the side of the cardiovascular system: tachycardia, increased blood pressure;
- From the nervous system: depression of the respiratory system, muscle rigidity, involuntary muscle contraction; during the period of recovery from general anesthesia - hallucinations, psychomotor agitation, psychosis, prolonged disorientation;
- From the digestive system: nausea, hypersalivation;
- On the part of the respiratory system: shortness of breath, obstruction of the upper respiratory tract due to retraction of the tongue and spasm of the chewing muscles, salivation and high bronchial secretion;
- Local reactions: pain syndrome at the injection site and hyperemia along the vein.
Overdose
The main symptoms (with intravenous administration of high doses - 3 mg / kg): respiratory depression.
Therapy: artificial ventilation of the lungs. With hallucinations, it is advisable to use antipsychotics (haloperidol), with convulsive syndrome, diazepam is prescribed. If necessary, symptomatic treatment is carried out.
special instructions
The use of Ketamine is indicated only in an ambulance or hospital setting.
When using the drug, the patient may experience retraction of the tongue or spasm of the chewing muscles, so it is necessary to control the respiratory function, especially the patency of the upper respiratory tract.
When carrying out premedication, it is recommended to include in the composition of medicines: atropine or methocinium iodide - to prevent an increase in the secretion of the salivary glands and mucous membranes; diazepam (i / m or i / v) - to prevent uncontrolled twitching and muscle stiffness; diazepam or droperidol - to prevent the development of psychomimetic effects.
Slow administration of the main dose of the drug, which should not exceed 3 mg per 1 kg of patient weight, and inhalation with a mixture of air and oxygen in a ratio of 2: 1 are recommended.
When carrying out surgical interventions on the larynx and pharynx using Ketamine, it is recommended to be careful and use muscle relaxants.
Influence on the ability to drive vehicles and complex mechanisms
After using Ketamine for at least 24 hours, patients should refrain from driving.
Application during pregnancy and lactation
Ketamine is not prescribed during pregnancy / lactation.
With impaired renal function
In severe renal failure, Ketamine is contraindicated.
Drug interactions
The drug enhances the effect of narcotic analgesics, antipsychotics, drugs for general anesthesia, anxiolytics (tranquilizers) and other drugs that depress the central nervous system.
The combination with anxiolytics, antipsychotics weakens the cardiac stimulating effect of ketamine.
The use of ketamine is possible only 1-2 days after the discontinuation of lithium and lincomycin preparations, 15 days after stopping the intake of monoamine oxidase inhibitors.
The drug solution should not be mixed with barbiturates in the same syringe.
Ketamine does not affect the effect of suxamethonium and pancuronium, enhances the muscle relaxant effect of ditilin and tubocurarine.
The simultaneous use of droperidol, sibazone and other benzodiazepines reduces the risk of developing arterial hypertension, tachycardia, motor and psychomimetic activity.
Since the simultaneous use of ketamine with drugs that have a stimulating effect on the cardiovascular system and sympathomimetics leads to an increase in arrhythmogenic and hypertensive effects, an increase in myocardial oxygen demand, it is recommended to avoid these combinations.
Patients taking thyroid hormones and iodine-containing drugs during general anesthesia are at greater risk of tachycardia and high blood pressure.
Analogs
Ketamine analogs are: Calypsol, Ketalar, Ketanest.
Terms and conditions of storage
Store in a dark place. Keep out of the reach of children.
Shelf life is 2 years.
Terms of dispensing from pharmacies
It is used only in a hospital setting.
Reviews about ketamine
Reviews of Ketamine are few. The drug is used only in a hospital setting, anesthesiologists indicate its high efficiency and good tolerance.
Price for ketamine in pharmacies
The approximate price for Ketamine in ampoules (5 pcs. 2 ml each) is 100-105 rubles. It is impossible to buy the drug on your own, it is purchased by medical institutions.
Maria Kulkes Medical journalist About the author
Education: First Moscow State Medical University named after I. M. Sechenov, specialty "General Medicine".
Information about the drug is generalized, provided for informational purposes only and does not replace the official instructions. Self-medication is hazardous to health!
