Uses for Ketamine Hydrochloride
Ketamine hydrochloride injection is indicated as the sole
anesthetic agent for diagnostic and surgical procedures that do not require
skeletal muscle relaxation. Ketamine hydrochloride is best suited for short
procedures but it can be used, with additional doses, for longer procedures.
Ketamine hydrochloride injection is indicated for the
induction of anesthesia prior to the administration of other general anesthetic
agents.
Ketamine hydrochloride injection is indicated to
supplement low-potency agents, such as nitrous oxide.
Specific areas of application are described in the CLINICAL
PHARMACOLOGY Section.
Dosage for Ketamine Hydrochloride
Note: Barbiturates and ketamine hydrochloride, being
chemically incompatible because of precipitate formation, should not be
injected from the same syringe.
If the ketamine hydrochloride dose is augmented with
diazepam, the two drugs must be given separately. Do not mix ketamine
hydrochloride and diazepam in syringe or infusion flask. For additional
information on the use of diazepam, refer to the WARNINGS and DOSAGE AND
ADMINISTRATION Sections of the diazepam insert.
Preoperative Preparations
- While vomiting has been reported following ketamine
hydrochloride administration, some airway protection may be afforded because of
active laryngeal-pharyngeal reflexes. However, since aspiration may occur with
ketamine hydrochloride and since protective reflexes may also be diminished by
supplementary anesthetics and muscle relaxants, the possibility of aspiration
must be considered. Ketamine hydrochloride is recommended for use in the patient
whose stomach is not empty when, in the judgment of the practitioner, the
benefits of the drug outweigh the possible risks.
- Atropine, scopolamine, or another drying agent should be
given at an appropriate interval prior to induction.
Onset And Duration
Because of rapid induction following the initial
intravenous injection, the patient should be in a supported position during
administration.
The onset of action of ketamine hydrochloride is rapid;
an intravenous dose of 2 mg/kg (1 mg/lb) of body weight usually produces
surgical anesthesia within 30 seconds after injection, with the anesthetic effect
usually lasting five to ten minutes. If a longer effect is desired, additional
increments can be administered intravenously or intramuscularly to maintain
anesthesia without producing significant cumulative effects.
Intramuscular doses, in a range of 9 to 13 mg/kg (4 to 6
mg/lb) usually produce surgical anesthesia within 3 to 4 minutes following
injection, with the anesthetic effect usually lasting 12 to 25 minutes.
Dosage
As with other general anesthetic agents, the individual
response to ketamine hydrochloride is somewhat varied depending on the dose,
route of administration, and age of patient, so that dosage recommendation cannot
be absolutely fixed. The drug should be titrated against the patient's
requirements.
Induction
Intravenous Route
The initial dose of ketamine hydrochloride administered
intravenously may range from 1 mg/kg to 4.5 mg/kg (0.5 to 2 mg/lb). The average
amount required to produce five to ten minutes of surgical anesthesia has been
2 mg/kg (1 mg/lb).
Alternatively, in adult patients an induction dose of 1
mg to 2 mg/kg intravenous ketamine at a rate of 0.5 mg/kg/min may be used for
induction of anesthesia. In addition, diazepam in 2 mg to 5 mg doses, administered
in a separate syringe over 60 seconds, may be used. In most cases, 15 mg of
intravenous diazepam or less will suffice. The incidence of psychological
manifestations during emergence, particularly dream-like observations and
emergence delirium, may be reduced by this induction dosage program.
Note: The 100 mg/mL concentration of ketamine
hydrochloride should not be injected intravenously without proper dilution. It
is recommended the drug be diluted with an equal volume of either Sterile Water
for injection, USP, Normal Saline, or 5% Dextrose in Water.
Rate of Administration
It is recommended that ketamine hydrochloride be
administered slowly (over a period of 60 seconds). More rapid administration
may result in respiratory depression and enhanced pressor response.
Intramuscular Route
The initial dose of ketamine hydrochloride administered
intramuscularly may range from 6.5 to 13 mg/kg (3 to 6 mg/lb). A dose of 10
mg/kg (5 mg/lb) will usually produce 12 to 25 minutes of surgical anesthesia.
Maintenance Of Anesthesia
The maintenance dose should be adjusted according to the
patient's anesthetic needs and whether an additional anesthetic agent is
employed.
Increments of one-half to the full induction dose may be
repeated as needed for maintenance of anesthesia. However, it should be noted
that purposeless and tonic-clonic movements of extremities may occur during the
course of anesthesia. These movements do not imply a light plane and are not indicative
of the need for additional doses of the anesthetic.
It should be recognized that the larger the total dose of
ketamine hydrochloride administered, the longer will be the time to complete recovery.
Adult patients induced with ketamine hydrochloride
augmented with intravenous diazepam may be maintained on ketamine hydrochloride
given by slow microdrip infusion technique at a dose of 0.1 to 0.5 mg/minute,
augmented with diazepam 2 to 5 mg administered intravenously as needed. In many
cases 20 mg or less of intravenous diazepam total for combined induction and
maintenance will suffice. However, slightly more diazepam may be required
depending on the nature and duration of the operation, physical status of the
patient, and other factors. The incidence of psychological manifestations
during emergence, particularly dream-like observations and emergence delirium,
may be reduced by this maintenance dosage program.
Dilution
To prepare a dilute solution containing 1 mg of ketamine
per mL, aseptically transfer 10 mL from a 50 mg per mL vial or 5 mL from a 100
mg per mL vial to 500 mL of 5% Dextrose Injection, USP or Sodium Chloride
(0.9%) Injection, USP (Normal Saline) and mix well. The resultant solution will
contain 1 mg of ketamine per mL.
The fluid requirements of the patient and duration of
anesthesia must be considered when selecting the appropriate dilution of
ketamine hydrochloride injection. If fluid restriction is required, ketamine hydrochloride
injection can be added to a 250 mL infusion as described above to provide a
ketamine hydrochloride concentration of 2 mg/mL. Ketamine hydrochloride
injection 10 mg/mL vials are not recommended for dilution.
Supplementary Agents
Ketamine hydrochloride is clinically compatible with the
commonly used general and local anesthetic agents when an adequate respiratory
exchange is maintained.
The regimen of a reduced dose of ketamine hydrochloride
supplemented with diazepam can be used to produce balanced anesthesia by
combination with other agents such as nitrous oxide and oxygen.
HOW SUPPLIED
Ketamine hydrochloride injection is supplied as the
hydrochloride in concentrations equivalent to ketamine base.
NDC 42023-137-10 - Each 20-mL multi-dose vial contains 10
mg/mL. Supplied in cartons of 10.
NDC 42023-138-10 - Each 10-mL multi-dose vial contains 50
mg/mL. Supplied in cartons of 10.
NDC 42023-139-10 - Each 5-mL multi-dose vial contains 100
mg/mL. Supplied in cartons of 10.
Store between 20° to 25°C (68° to 77°F). (See USP
controlled room temperature.)
Protect from light.
Manufactured and Distributed by: JHP Pharmaceuticals, LLC,
Rochester, MI 48307. Revised: Feb 2013