Ketalar (ketamine)

Ketalar (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.

• Studies conducted in young animals and children suggest repeated or prolonged use of general anesthetic or sedation drugs in children younger than 3 years may have negative effects on their developing brains. Discuss with parents and caregivers the benefits, risks, and timing and duration of surgery or procedures requiring anesthetic and sedation drugs.
• Due to the residual anesthetic effects and the potential for drowsiness, advise patients not to drive an automobile, operate hazardous machinery, or engage in hazardous activities within 24 hours of receiving Ketalar.

Due to the potential for salivation during Ketalar administration, administer an antisialagogue prior to induction of anesthesia.

In individuals with a history of chronic ketamine use for off-label indications, there have been case reports of genitourinary pain that may be related to the ketamine treatment, not the underlying condition. Consider cessation of ketamine if genitourinary pain continues in the setting of other genitourinary symptoms.

Serious side effects include:

• Hemodynamic Instability
• Emergence Reactions
• Respiratory Depression
• Pediatric Neurotoxicity 
• Drug-Induced Liver Injury

The following adverse reactions associated with the use of Ketalar were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

• Cardiovascular disorders: Elevated blood pressure, heart rate, and cardiac index; decreases in blood pressure and heart rate; arrhythmias; cardiac decompensation (in patients with suspected catecholamine depletion).
• Eye disorders: Diplopia, nystagmus, elevation in intraocular pressure.
• Gastrointestinal disorders: Anorexia, nausea, vomiting, hepatobiliary dysfunction.
• Administration site disorders: Local pain and exanthema at the injection site. Immune system disorders: Anaphylaxis.
• Neurologic disorders: Emergence reactions (post-operative delirium). During administration, enhanced muscle tone and spasms (resembling a partial motor or generalized motor seizure).
• Psychiatric disorders: Adverse psychiatric events have occurred and/or persisted days to weeks after ketamine exposure.
• Renal and urinary disorders: In individuals with history of chronic ketamine use or abuse, lower urinary tract and bladder symptoms including dysuria, increased urinary frequency, urgency, urge incontinence, and hematuria have been reported. In addition, diagnostic studies performed to assess the cause of these symptoms have reported cystitis (including cystitis non-infective, cystitis interstitial, cystitis ulcerative, cystitis erosive and cystitis hemorrhagic) as well as hydronephrosis and reduced bladder capacity.
• Respiratory disorders: Respiratory depression and apnea following rapid intravenous administration of high doses of Ketalar; laryngospasm, and airway obstruction.
• Skin and subcutaneous tissue disorders: Transient erythema and/or morbilliform rash

Drug Abuse And Dependence

Controlled Substance

Ketalar contains ketamine, a Schedule III controlled substance under the Controlled Substance Act.

Abuse

Individuals with a history of drug abuse or dependence may be at greater risk for abuse and misuse of Ketalar. Abuse is the intentional, non-therapeutic use of a drug, even once, for its psychological or physiological effects. Misuse is the intentional use, for therapeutic purposes, of a drug by an individual in a way other than prescribed by a health care provider or for whom it was not prescribed.

• In a context of drug abuse, Ketalar may produce a variety of symptoms including anxiety, dysphoria, disorientation, insomnia, flashback, hallucinations, and feelings of floating, detachment and being “spaced out”.
• Recurrent high-dose ketamine misuse or abuse may be associated with memory and/or attention impairment.

Dependence

Physical dependence has been reported with prolonged use of ketamine. Physical dependence is a state that develops as a result of physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or significant dosage reduction of a drug.

Withdrawal symptoms have been reported after the discontinuation of frequently used (more than weekly), large doses of ketamine for long periods of time. Reported symptoms of withdrawal associated with daily intake of large doses of ketamine include craving, fatigue, poor appetite, and anxiety.

Tolerance has been reported with prolonged use of ketamine. Tolerance is a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to produce the same effect that was once obtained at a lower dose).

Important Dosage And Administration Information

Ketalar should be administered by or under the direction of physicians experienced in the administration of general anesthetics, maintenance of a patent airway, and oxygenation and ventilation. Continuously monitor vital signs in patients receiving Ketalar.

Emergency airway equipment must be immediately available.

Do not administer the 100 mg/mL concentration of Ketalar intravenously without proper dilution. Must be used immediately after dilution.

While some degree of airway protection may be afforded due to active laryngeal-pharyngeal reflexes, vomiting and aspiration may occur with Ketalar. Ketalar is not recommended for use in patients who have not followed nil per os guidelines.

Recommended Dosage And Administration

The Ketalar dosage must be individualized and titrated to the desired clinical effect.

If a longer duration of effect is desired, additional increments can be administered intravenously or intramuscularly to maintain anesthesia. However, a higher total dose will result in a longer time to complete recovery.

Induction Of Anesthesia

Intravenous Route

The initial dose of Ketalar administered intravenously may range from 1 mg/kg to 4.5 mg/kg. The average amount required to produce 5 to 10 minutes of surgical anesthesia within 30 seconds following injection is 2 mg/kg. Administer Ketalar slowly (i.e., over a period of 60 seconds). Rapid administration may result in respiratory depression and enhanced vasopressor response. The induction dose may be administered as an intravenous infusion at a rate of 0.5 mg/kg/min.

Intramuscular Route

The initial dose of Ketalar administered intramuscularly may range from 6.5 to 13 mg/kg. A dose of 9 to 13 mg/kg usually produces surgical anesthesia within 3 to 4 minutes following injection, with the anesthetic effect usually lasting 12 to 25 minutes. Administer a benzodiazepine, if clinically indicated, for the prevention of neuropsychological manifestations during emergence from anesthesia.

Maintenance Of Anesthesia

Adjust the maintenance dose according to the patient's anesthetic needs and whether an additional anesthetic agent is administered.

Repeat increments of one-half to the full induction dose as needed for maintenance of anesthesia. Purposeless and tonic-clonic movements of extremities may occur during the course of ketamine anesthesia. These movements do not imply a light plane and are not indicative of the need for additional doses of the anesthetic.

Ketalar given by slow microdrip infusion technique at a dose of 0.1 to 0.5 mg/minute will maintain general anesthesia in adult patients induced with Ketalar. Augment Ketalar with an intravenous benzodiazepine for the prevention of neuropsychological manifestations during emergence.

Supplement To Other Anesthetic Agents

Ketalar can be administered to supplement other general and local anesthetic agents. Continuously monitor patients for changes in respiratory and hemodynamic parameters.

A reduced dose of Ketalar can be used to produce balanced anesthesia when used in combination with other anesthetic agents.

Theophylline Or Aminophylline

Concomitant administration of Ketalar and theophylline or aminophylline may lower the seizure threshold. Consider using an alternative to Ketalar in patients receiving theophylline or aminophylline.

Sympathomimetics And Vasopressin

Sympathomimetics and vasopressin may enhance the sympathomimetic effects of ketamine. Closely monitor vital signs when Ketalar and sympathomimetics or vasopressin are co-administered and consider dose adjustment individualized to the patient's clinical situation.
Benzodiazepines, Opioid Analgesics, Or Other CNS Depressants
Concomitant use of ketamine with opioid analgesics, benzodiazepines, or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Closely monitor neurological status and respiratory parameters, including respiratory rate and pulse oximetry, when Ketalar and opioid analgesics, benzodiazepines, or other CNS depressants are co-administered. Consider dose adjustment individualized to the patient's clinical situation.

Ketalar use in pregnancy, including obstetrics (either vaginal or abdominal delivery), is not recommended because safe use has not been established