WARNINGS
Cardiac function should be continually monitored during the
procedure in patients found to have hypertension or cardiac decompensation.
Postoperative
confusional states may occur during the recovery period. (See SPECIAL
NOTE.)
Respiratory depression may occur with
overdosage or too rapid a rate of administration of ketamine, in which case
supportive ventilation should be employed. Mechanical support of respiration
is preferred to administration of analeptics.
PRECAUTIONS
General
Ketamine should be used by or under the direction of physicians
experienced in administering general anesthetics and in maintenance of an
airway and in the control of respiration.
Because pharyngeal
and laryngeal reflexes are usually active, ketamine should not be used alone
in surgery or diagnostic procedures of the pharynx, larynx, or bronchial tree.
Mechanical stimulation of the pharynx should be avoided, whenever possible,
if ketamine is used alone. Muscle relaxants, with proper attention to respiration,
may be required in both of these instances.
Resuscitative
equipment should be ready for use.
The incidence
of emergence reactions may be reduced if verbal and tactile stimulation
of the patient is minimized during the recovery period. This does not preclude
the monitoring of vital signs (see SPECIAL NOTE).
The intravenous dose should be administered
over a period of 60 seconds. More rapid administration may result in respiratory
depression or apnea and enhanced pressor response.
In
surgical procedures involving visceral pain pathways, ketamine should be supplemented
with an agent which obtunds visceral pain.
Use with
caution in the chronic alcoholic and the acutely alcohol-intoxicated patient.
An
increase in cerebrospinal fluid pressure has been reported following administration
of ketamine. Use with extreme caution in patients with preanesthetic elevated
cerebrospinal fluid pressure.
Information for Patients
As appropriate, especially in cases where early discharge
is possible, the duration of ketamine and other drugs employed during the
conduct of anesthesia should be considered. The patients should be cautioned
that driving an automobile, operating hazardous machinery or engaging in hazardous
activities should not be undertaken for 24 hours or more (depending upon the
dosage of ketamine and consideration of other drugs employed) after anesthesia.
Drug Interactions
Prolonged recovery time may occur if barbiturates and/or
narcotics are used concurrently with ketamine.
Ketamine
is clinically compatible with the commonly used general and local anesthetic
agents when an adequate respiratory exchange is maintained.
Usage in Pregnancy
Since the safe use in pregnancy, including obstetrics (either
vaginal or abdominal delivery), has not been established, such use is not
recommended (see ANIMAL PHARMACOLOGY AND TOXICOLOGY, Reproduction).
Geriatric Use
Clinical studies of ketamine hydrochloride did not include
sufficient numbers of subjects aged 65 and over to determine whether they
respond differently from younger subjects. Other reported clinical experience
has not identified differences in responses between the elderly and younger
patients. In general, dose selection for an elderly patient should be cautious,
usually starting at the low end of the dosing range, reflecting the greater
frequency of decreased hepatic, renal, or cardiac function, and of concomitant
disease or other drug therapy.
Pediatric Use
Safety and effectiveness in pediatric patients below the
age of 16 have not been established.
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