KETALAR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for KETALAR (KETALAR).
Noncompetitive NMDA receptor antagonist; inhibits glutamate activity, modulates opioid receptors, and interacts with other neurotransmitter systems.
| Metabolism | Primarily hepatic via N-demethylation by CYP3A4 and CYP2B6 to norketamine, then further metabolized via hydroxylation and conjugation. |
| Excretion | Renal: 90% as metabolites (norketamine, dehydronorketamine); unchanged: 2-4%. Fecal: <3%. |
| Half-life | Terminal elimination half-life: 2.5-3 hours (ketamine); norketamine: 12 hours. Clinical context: Short half-life facilitates rapid recovery, but context-sensitive half-life increases with infusion duration. |
| Protein binding | 12-50% primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 1-2 L/kg (large, indicating extensive tissue distribution). Highly lipophilic, crosses blood-brain barrier rapidly. |
| Bioavailability | Oral: 16-24% (extensive first-pass metabolism); Intranasal: 45-50%; IM: 93%; Subcutaneous: 100%. |
| Onset of Action | IV: 30-60 seconds; IM: 1-5 minutes; Oral: 15-30 minutes; Intranasal: 5-15 minutes. |
| Duration of Action | IV/IM: 5-15 minutes (anesthetic), 30-60 minutes (analgesic); Oral: 1-2 hours; Intranasal: 15-30 minutes. Context: Subanesthetic doses produce prolonged analgesia. |
| Action Class | General anaesthetic agents |
| Brand Substitutes | Ketam 10mg Injection, Ketamax 10mg Injection, Aneket 10mg Injection, Ketmin 10mg Injection |
1-4.5 mg/kg IV or 6.5-13 mg/kg IM for induction of anesthesia; 0.1-0.5 mg/kg/min IV infusion for maintenance.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for GFR >10 mL/min; for GFR <10 mL/min, consider dose reduction by 50% due to accumulation of active metabolite norketamine. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use or use with extreme caution, reduce dose by 75%. |
| Pediatric use | Induction: 1-2 mg/kg IV or 4-6 mg/kg IM; maintenance: 0.5-1 mg/kg IV boluses or 10-50 mcg/kg/min IV infusion. Titrate to effect. |
| Geriatric use | Reduce initial dose by 50% (e.g., 0.5-2 mg/kg IV) and titrate slowly due to increased sensitivity and risk of delirium; consider lower infusion rates (0.1-0.3 mg/kg/min). |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for KETALAR (KETALAR).
| Breastfeeding | Excreted into breast milk in low amounts; M/P ratio unknown. Use caution, especially with repeated doses or in neonates with hepatic impairment. |
| Teratogenic Risk | First trimester: Limited human data; animal studies show no teratogenicity. Second/third trimester: Use only if clearly needed; may cause neonatal respiratory depression, hypotonia, and altered neurobehavior if used near delivery. |
| Fetal Monitoring |
■ FDA Black Box Warning
Hemodynamic instability (hypertension, tachycardia) and increased intracranial pressure; risk of emergent reactions (hallucinations, delirium); potential for abuse and dependence.
| Serious Effects |
Hypersensitivity to ketamine; conditions where elevated blood pressure or intracranial pressure would be dangerous (e.g., severe hypertension, cerebral hemorrhage); severe coronary artery disease; history of psychotic disorders.
| Precautions | Monitor blood pressure and cardiac function; use with caution in patients with hypertension, heart failure, or increased intracranial pressure; emergence reactions may occur; laryngospasm risk; respiratory depression. |
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| Monitor maternal vital signs (BP, HR, respiratory rate), oxygen saturation, and depth of anesthesia. Fetal heart rate monitoring during prolonged use. Assess neonatal respiratory status and Apgar scores if used near delivery. |
| Fertility Effects | No significant adverse effects on fertility reported in animal studies; human data lacking. |