Ketamine Hydrochloride

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. KETALAR is a general anesthetic indicated: as the sole anesthetic agent for diagnostic and surgical procedures that do not require skeletal muscle relaxation ( 1 ) for the induction of anesthesia prior to the administration of other general anesthetic agents ( 1 ) as a supplement to other anesthetic agents ( 1 ).

KETALAR injection is a clear, colorless, sterile solution available in multiple-dose vials containing either 10 mg ketamine base (equivalent to 11.53 mg ketamine hydrochloride), 50 mg ketamine base (equivalent to 57.67 mg ketamine hydrochloride) or 100 mg ketamine base (equivalent to 115.33 mg ketamine hydrochloride). 200 mg/20 mL (10 mg/mL) 500 mg/10 mL (50 mg/mL) 500 mg/5 mL (100 mg/mL) Injection: 200 mg/20 mL (10 mg/mL), 500 mg/10 mL (50 mg/mL), and 500 mg/5 mL (100 mg/mL) multiple-dose vials ( 3 ).

KETALAR is contraindicated in patients for whom a significant elevation of blood pressure would constitute a serious hazard [see Warnings and Precautions ( 5.1 ) ]. KETALAR is contraindicated in patients with known hypersensitivity to ketamine or to any excipient [see Adverse Reactions ( 6 ) ]. In patients for whom a significant elevation of blood pressure would be a serious hazard ( 4 ). Known hypersensitivity to ketamine or to any excipient ( 4 ).

Hemodynamic Instability: Monitor vital signs and cardiac function during KETALAR administration. ( 5.1 ) Emergence Reactions: Postoperative confusional states may occur during the recovery period. Reduce by minimizing verbal, tactile, and visual stimulation of the patient. ( 5.2 ) Risk of Respiratory Depression: May occur with overdosage or too rapid a rate of administration. Maintain adequate oxygenation and ventilation. ( 5.3 ) Risks of KETALAR alone for Procedures of the Pharynx, Larynx, or Bronchial Tree : Pharyngeal and laryngeal reflexes are not suppressed with KETALAR when it is used alone. Avoid use as a sole anesthetic agent in surgery or diagnostic procedures of the pharynx, larynx, or bronchial tree. Muscle relaxants may be required. ( 5.4 ) Pediatric Neurotoxicity: Long-term cognitive deficits may occur when used for longer than 3 hours in children ≤3 years ( 5.5 )

5.1 Hemodynamic Instability Transient increases in blood pressure, heart rate, and cardiac index are frequently observed following administration of KETALAR. Decreases in blood pressure and heart rate, arrhythmias, and cardiac decompensation have also been observed. Monitor vital signs and cardiac function during KETALAR administration. KETALAR is contraindicated in patients for whom a significant elevation of blood pressure would constitute a serious hazard [see Contraindications ( 4 )] .

5.2 Emergence Reactions Emergence delirium (postoperative confusional states or agitation) has occurred in approximately 12% of patients during the recovery period, and the duration is generally a few hours. The neuropsychological manifestations vary in severity between pleasant dream-like states, vivid imagery, hallucinations, and emergence delirium. In some cases, these states have been accompanied by confusion, excitement, and irrational behavior, which have been recalled as unpleasant experiences. No residual psychological effects are known to have resulted from use of KETALAR during induction and maintenance of anesthesia. Intramuscular administration results in a lower incidence of emergence reactions. The incidence of psychological manifestations during emergence, particularly dream-like observations and emergence delirium, may be reduced by using lower recommended dosages of KETALAR in conjunction with an intravenous benzodiazepine during induction and maintenance of anesthesia [see Dosage and Administration ( 2.3 )] . Also, these reactions may be reduced if verbal, tactile, and visual stimulation of the patient is minimized during the recovery period. This does not preclude the monitoring of vital signs.

5.3 Respiratory Depression Respiratory depression may occur with overdosage or a rapid rate of administration of KETALAR. Maintain adequate oxygenation and ventilation.

5.4 Risks of Ketalar Alone for Procedures of the Pharynx, Larynx, or Bronchial Tree KETALAR does not suppress pharyngeal and laryngeal reflexes. Avoid KETALAR administration as a sole anesthetic agent during procedures of the pharynx, larynx, or bronchial tree, including mechanical stimulation of the pharynx. Muscle relaxants may be required for successful completion of procedures of the pharynx, larynx, or bronchial tree.

5.5 Pediatric Neurotoxicity Published animal studies demonstrate that the administration of anesthetic and sedation drugs that block NMDA receptors and/or potentiate GABA activity increase neuronal apoptosis in the developing brain and result in long-term cognitive deficits when used for longer than 3 hours. The clinical significance of these findings is not clear. However, based on the available data, the window of vulnerability to these changes is believed to correlate with exposures in the third trimester of gestation through the first several months of life, but may extend out to approximately three years of age in humans [see Use in Specific Populations ( 8.1 , 8.4 ), Nonclinical Toxicology ( 13.2 )]. Some published studies in children suggest that similar deficits may occur after repeated or prolonged exposures to anesthetic agents early in life and may result in adverse cognitive or behavioral effects. These studies have substantial limitations, and it is not clear if the observed effects are due to the anesthetic/sedation drug administration or other factors such as the surgery or underlying illness. Anesthetic and sedation drugs are a necessary part of the care of children needing surgery, other procedures, or tests that cannot be delayed, and no specific medications have been shown to be safer than any other. Decisions regarding the timing of any elective procedures requiring anesthesia should take into consideration the benefits of the procedure weighed against the potential risks.

5.6 Drug-Induced Liver Injury Ketamine administration is associated with hepatobiliary dysfunction (most often a cholestatic pattern), with recurrent use (e.g., misuse/abuse or medically supervised unapproved indications). Biliary duct dilatation, stricture, stenosis , and obstructions have also been reported with recurrent use. Obtain baseline LFTs, including alkaline phosphatase and gamma glutamyl transferase, in patients receiving ketamine as part of a treatment plan that utilizes recurrent dosing. Monitor those receiving recurrent ketamine at periodic intervals during treatment. Sclerosing cholangitis has been reported in patients on long term ketamine therapy. Ketamine-induced sclerosing cholangitis is potentially reversible with ketamine discontinuation. If signs or symptoms consistent with sclerosing cholangitis (e.g., a cholestatic pattern of increased liver function tests with grossly elevated gamma glutamyl transferase and alkaline phosphatase levels) are observed in a patient receiving ketamine, discontinue ketamine immediately and refer the patient to the appropriate specialist for evaluation.

5.7 Urological Complications Serious renal and urinary complications, including cystitis, reduced bladder capacity, ureteral stenosis, ureteral obstruction, and hydronephrosis have been reported with long-term ketamine use or abuse. Ureteral stenosis and ureteral obstruction can lead to hydronephrosis and renal impairment and may require emergency interventions such as nephrostomy tube placement, ureteral stenting, or surgical intervention. If signs or symptoms of urinary obstruction or severe lower urinary tract symptoms are observed, discontinue ketamine and refer for urgent urological evaluation.

5.8 Increase in Cerebrospinal Fluid Pressure An increase in intracranial pressure has been reported following administration of ketamine hydrochloride. Patients with elevated intracranial pressure should be in a monitored setting with frequent neurologic assessments.

5.9 Drug Interactions Theophylline or Aminophylline : Concomitant administration of KETALAR and theophylline or aminophylline may lower the seizure threshold [see Drug Interactions ( 7.1 )] . 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 [see Drug Interactions ( 7.2 )] . 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 [see Drug Interactions ( 7.3 )] . Closely monitor neurological status and respiratory parameters, including respiratory rate and pulse oximetry, when KETALR and opioid analgesics, benzodiazepines, or other CNS depressants are co-administered. Consider dose adjustment individualized to the patient’s clinical situation.

The following clinically significant adverse reactions are described elsewhere in the labeling: Hemodynamic Instability [see Warnings and Precautions ( 5.1 )] Emergence Reactions [see Warnings and Precautions ( 5.2 )] Respiratory Depression [see Warnings and Precautions ( 5.3 )] Pediatric Neurotoxicity [see Warnings and Precautions ( 5.5 )] Drug-Induced Liver Injury [see Warnings and Precautions ( 5.6 )] 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, biliary duct dilatation, biliary duct stricture and/or stenosis with or without evidence of biliary obstruction; secondary sclerosing cholangitis [see Warnings and Precautions ( 5.6 )]. Administration site disorders : Local pain and exanthema at the injection site. Immune system disorders : Anaphylaxis. Neurologic disorders : Emergence reactions (post-operative delirium), [see Warnings and Precautions ( 5.2 )]. 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 a history of long-term ketamine use or abuse, urinary tract complications related to cystitis, reduced bladder capacity, ureteral stenosis (strictures), ureteral obstruction, and hydronephrosis have been reported [see Warnings and Precautions (5.7)] . Cystitis (including cystitis non-infective, cystitis interstitial, cystitis ulcerative, cystitis erosive and cystitis hemorrhagic) and reduced bladder capacity may present with genitourinary pain, dysuria, increased urinary frequency, urgency, urge incontinence, and hematuria. Ureteral stenosis (strictures), ureteral obstruction, and hydronephrosis may present with flank and/or pelvic pain, recurrent urinary tract infections, hematuria, nausea and vomiting, and acute kidney injury. 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 The most common adverse reactions are emergence reactions and elevated blood pressure and pulse ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Par Health at 1-800-828-9393 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

Theophylline or Aminophylline : Do not co-administer with KETALAR as concomitant use may lower the seizure threshold ( 7.1 ). Sympathomimetics and Vasopressin : Closely monitor vital signs when co-administered with KETALAR. Consider dose adjustment individualized to the patient’s clinical situation ( 7.2 ). Benzodiazepines, Opioid Analgesics, or other CNS Depressants : Concomitant use may result in profound sedation, respiratory depression, coma, or death. Concomitant use of opioid analgesics may prolong recovery time. ( 7.3 ).

7.1 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.

7.2 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.

7.3 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 [see Warnings and Precautions ( 5.9 )] . Opioid analgesics administered concomitantly with KETALAR may prolong time to complete recovery from anesthesia.

8.1 Pregnancy Risk Summary Available data on the use of ketamine in pregnant women mostly describe its use at the time of cesarean section and have not identified a drug-associated risk of adverse maternal or fetal outcomes. The data are limited by retrospective collection, small sample sizes, and a lack of long-term follow-up. There are no available data on ketamine use during other stages of pregnancy to allow for an evaluation of drug-associated risk of major birth defects or miscarriage. 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. In rabbits, developmental delays and increased fetal resorptions were noted at 0.6 times the human dose. Published studies in pregnant primates demonstrate that the administration of anesthetic and sedation drugs that block NMDA receptors and/or potentiate GABA activity during the period of peak brain development increases neuronal apoptosis in the developing brain of the offspring when used for longer than 3 hours. There are no data on pregnancy exposures in primates corresponding to periods prior to the third trimester in humans. The clinical significance of these nonclinical findings is not known, and the benefits of appropriate anesthesia in pregnant women who require procedures should be balanced with the potential risks suggested by the nonclinical data. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data Pregnant rats were treated intramuscularly with 20 mg/kg ketamine (0.3 times the human dose of 10 mg/kg IM based on body surface area) on either Gestation Days 6 to 10 or Gestation Days 11 to 15. Ketamine treatment produced an increased incidence of hypoplastic skull, phalanges, and sternebrae in the pups. Pregnant rabbits were treated intramuscularly with 20 mg/kg ketamine (0.6 times the human dose of 10 mg/kg IM based on body surface area) on either Gestation Days 6 to 10 or Gestation Days 11 to 15. An increase in resorptions and skeletal hypoplasia of the fetuses were noted. Additional pregnant rabbits were treated intramuscularly with a single dose 60 mg/kg (1.9 times the human dose of 10 mg/kg IM based on body surface area) on Gestation Day 6 only. Skeletal hypoplasia was reported in the fetuses. In a study where pregnant rats were treated intramuscularly with 20 mg/kg ketamine (0.3 times the human dose of 10 mg/kg IM based on body surface area) from Gestation Day 18 to 21. There was a slight increase in incidence of delayed parturition by one day in treated dams of this group. No adverse effects on the litters or pups were noted; however, learning and memory assessments were not completed. Three (3) pregnant beagle dogs were treated intramuscularly with 25 mg/kg ketamine (1.3 times the human dose of 10 mg/kg IM based on body surface area) twice weekly for the three weeks of the first, second, and third trimesters of pregnancy, respectively, without the development of adverse effects in the pups. In a published study in primates, administration of an anesthetic dose of ketamine for 24 hours on Gestation Day 122 increased neuronal apoptosis in the developing brain of the fetus. In other published studies, administration of either isoflurane or propofol for 5 hours on Gestation Day 120 resulted in increased neuronal and oligodendrocyte apoptosis in the developing brain of the offspring. With respect to brain development, this time period corresponds to the third trimester of gestation in the human. The clinical significance of these findings is not clear; however, studies in juvenile animals suggest neuroapoptosis correlates with long-term cognitive deficits [see Warnings and Precautions ( 5.5 ), Use in Specific Populations ( 8.4 ), and Nonclinical Toxicology ( 13.2 )] .

8.2 Lactation Risk Summary Published literature describe the presence of ketamine and its metabolite in human milk. There are no data on the effects on the breastfed infants; however, infants should be monitored for sedation, respiratory depression, and increased muscle tone and spasms. There are no data on the effects of ketamine on milk production. Due to the potential for developmental neurotoxicity of ketamine in newborns and infants [ see subsection ( 8.4 )] , KETALAR treatment in lactating women should be limited to anesthesia. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for ketamine and any potential adverse effects on the breastfed child from ketamine or from the underlying maternal condition.

8.4 Pediatric Use Safety and effectiveness in pediatric patients below the age of 16 have not been established. Published juvenile animal studies demonstrate that the administration of anesthetic and sedation drugs, such as KETALAR, that either block NMDA receptors or potentiate the activity of GABA during the period of rapid brain growth or synaptogenesis, results in widespread neuronal and oligodendrocyte cell loss in the developing brain and alterations in synaptic morphology and neurogenesis. Based on comparisons across species, the window of vulnerability to these changes is believed to correlate with exposures in the third trimester of gestation through the first several months of life but may extend out to approximately 3 years of age in humans. In primates, exposure to 3 hours of ketamine that produced a light surgical plane of anesthesia did not increase neuronal cell loss, however, treatment regimens of 5 hours or longer of isoflurane increased neuronal cell loss. Data from isoflurane-treated rodents and ketamine-treated primates suggest that the neuronal and oligodendrocyte cell losses are associated with prolonged cognitive deficits in learning and memory. The clinical significance of these nonclinical findings is not known, and healthcare providers should balance the benefits of appropriate anesthesia in neonates and young children who require procedures with the potential risks suggested by the nonclinical data [see Warnings and Precautions ( 5.5 ), Use in Specific Populations ( 8.1 ), and Nonclinical Toxicology ( 13.2 )] .

8.5 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.

KETALAR, 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.