Pregnancy

Pregnancy Risk Summary There are no adequate and well-controlled studies of ketamine 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. 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 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. Clinical Considerations 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 ). Data Animal Data Pregnant rats were treated intramuscularly with 20 mg/kg ketamine (0.3 times the human intramuscular dose of 10 mg/kg 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 intramuscular dose of 10 mg/kg 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 intramuscular dose of 10 mg/kg 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 intramuscular dose of 10 mg/kg 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 pregnant beagle dogs were treated intramuscularly with 25 mg/kg ketamine (1.3 times the human intramuscular dose of 10 mg/kg 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/Pediatric Neurotoxicity , Pediatric Use , and ANIMAL TOXICOLOGY AND PHARMACOLOGY ).

Drug Interactions

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.

Indications And Usage

INDICATIONS AND USAGE Ketamine hydrochloride injection is indicated as the sole anesthetic agent for diagnostic and surgical procedures that do not require skeletal muscle relaxation. Ketamine hydrochloride injection 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.

Overdosage

Adverse Reactions

Contraindications