Ketamine

What it is and how it works

Mechanism of Action Ketamine hydrochloride injection, a racemic mixture of ketamine, is a non-selective, non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, an ionotropic glutamate receptor. The major circulating metabolite of ketamine (norketamine) demonstrated activity at the same receptor with less affinity. Norketamine is about 1/3 as active as ketamine in reducing halothane requirements (MAC) of the rat.

Indications

Ketamine hydrochloride injection is indicated: • as the sole anesthetic agent for diagnostic and surgical procedures that do not require skeletal muscle relaxation. • for the induction of anesthesia prior to the administration of other general anesthetic agents. • as a supplement to other anesthetic agents. Ketamine hydrochloride injection is a general anesthetic indicated: • as the sole anesthetic agent for diagnostic and surgical procedures that do not require skeletal muscle relaxation • for the induction of anesthesia prior to the administration of other general anesthetic agents • as a supplement to other anesthetic agents .

Dosage and administration (summary)

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

Contraindications

• Ketamine hydrochloride injection is contraindicated in patients for whom a significant elevation of blood pressure would constitute a serious hazard . • Ketamine hydrochloride injection is contraindicated in patients with known hypersensitivity to ketamine or to any excipient . • In patients for whom a significant elevation of blood pressure would be a serious hazard . • Known hypersensitivity to ketamine or to any excipient .

Warnings and precautions

• Hemodynamic Instability: Monitor vital signs and cardiac function during ketamine hydrochloride injection administration. • Emergence Reactions: Postoperative confusional states may occur during the recovery period. Reduce by minimizing verbal, tactile, and visual stimulation of the patient. • Risk of Respiratory Depression: May occur with overdosage or too rapid a rate of administration. Maintain adequate oxygenation and ventilation.

Pregnancy

Pregnancy Risk Summary There are no adequate and well-controlled studies of ketamine hydrochloride injection in pregnant women. In animal reproduction studies in rats developmental delays (hypoplasia of skeletal tissues) were noted at 0.3 times the human intramuscular dose of 10 mg/kg.

Storage and supply

How Supplied Ketamine Hydrochloride Injection, USP is a clear, colorless solution supplied as the hydrochloride salt in concentrations equivalent to ketamine base, as follows: Unit of sale Strength NDC 43066-117-05 Unit of 05 100 mg in 10 mL single-dose pre-filled syringe (10 mg/mL) 10 mg ketamine base (equivalent to 11.53 mg ketamine hydrochloride…

Source: Ketamine Hydrochloride (Ketamine Hydrochloride) — US FDA prescribing information, 2025-06-26, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.