Dosing and uses of Ketalar (ketamine)
Adult dosage forms and strengths
injectable solution: Schedule III
- 10mg/mL
- 50mg/mL
- 100mg/mL
Anesthesia Induction
Load
- IV: 1-4.5 mg/kg slow IV once
- Alternatively (off-label): 0.5-2 mg/kg slow IV if adjuvant drugs (eg, midazolam) are used, OR
- IM: 6.5-13 mg/kg IM once
- Alternatively (off-label): 4-10 mg/kg IM once if adjuvant drugs (eg, midazolam) are used
Maintenance
- 50% of IV ketamine induction dose administered PRN, OR
- 0.1-0.5 mg/min IV continuous infusion
Pediatric dosage forms and strengths
injectable solution: Schedule III
- 10mg/mL
- 50mg/mL
- 100mg/mL
Sedation/Analgesia (Off-label)
ACEP recommends as safe in children
3 months or older
Im
- 4-5 mg/kg IM once, ACEP Clinical Guidelines (Green 2004); may give a repeat dose (range 2-5 mg/kg) if sedation inadequate after 5-10 min or if additional doses are required
IV
- Various recommendations
- 1.5-2 mg/kg over 30-60 sec; may administer incremental doses of 0.5-2 mg/kg IV q5-15min PRN if initial sedation inadequate (Mace et al., Ann Emerg Med, 44: 342-377 [2004]), OR
- 0.25-0.5 mg/kg (Harriet Lane)
OraL
- 6-10 mg/kg PO once; mix with 0.2-0.3 mL/kg of a beverage; give 30 min before procedure
16 years or older
Load
- IV: 1-4.5 mg/kg slow IV once
- Alternatively (off-label): 0.5-2 mg/kg slow IV if adjuvant drugs (eg, midazolam) are used, OR
- IM: 6.5-13 mg/kg IM once
- Alternatively (off-label): 4-10 mg/kg IM once if adjuvant drugs (eg, midazolam) are used
Maintenance
- 50% of IV ketamine induction dose administered PRN, OR
- 0.1-0.5 mg/min IV continuous infusion
Ketalar (ketamine) adverse (side) effects
>10%
Emergence rxns
HTn
Increased cardiac output
Increased ICp
Tachycardia
Tonic-clonic movements
Visual hallucinations
Vivid dreams
1-10%
Bradycardia
Diplopia
Hypotension
Increased IOp
Injection-site pain
Nystagmus
<1%
Anaphylaxis
Cardiac arrhythmia
Depressed cough reflex
Fasciculations
Hypersalivation
Increased IOp
Increased metabolic rate
Hypertonia
Laryngospasm
Respiratory depression or apnea with large doses or rapid infusions
Warnings
Contraindications
Hypersensitivity
Conditions in which an increase in blood pressrue would be hazardous
Cautions
Increases ICP (head raising may alleviate); causes hypersalivation (may be controlled with atropine/glycopyrrolate)
Not for use alone in surgery or diagnostic procedures of the pharynx, or bronchial tree, mechanical stimulation of the pharynx, larynx, or bronchial tree; avoid mechanical stimulation of the pharynx if ketamine used alone
May cause CNS depression; use caution when operating heavy machinery; do not engage in hazardous activities or operate hazardous machinery for at least 24 hr after anesthesia
May cause dependence and tolerance with prolonged use; discontinuation of long term use has been associated with a withdrawal syndrome with psychotic features
Treat CNS abnormalities, CNS masses, or hydrocephalus as a relative contraindication, due to increased intracranial pressure produced by ketamine
Therapy may increase intraocular pressure, use with caution in patients with increased intraocular pressure; avoid use in patients with eye injury or other ophthalmic disorder
Glaucoma or acute globe injury may be considered a relative contraindication
Therapy may enhance sympathomimetic effect; use caution in patients with porphyria or a thyroid disorder; may consider porphyria and thyroid disorder or thyroid therapy a relative contraindication
Use caution in patients with coronary artery disease, catecholamine depletion, hypertension and tachycardia; monitor cardiac function continuously in patients with increased blood pressure, heart rate, and cardiac output, thereby increasing myocardial oxygen demand
Use caution in patients with cerebrospinal fluid pressure elevation; increase in cerebrospinal fluid pressure may be associated with use
Use with cautioin in chronic alcoholic patients or acutely intoxicated
Use requires patient monitoring, to be administered only by experienced personnel who are not actively engaged in the procedure or surgery; in nonintubated and/or nonmechanically ventilated patients, appropriate equipment and qualified personnel should be immediately available to use appropriate equipment for rapid institution of respiratory and/or cardiovascular support
Too rapid administration will cause respiratory depression
Do NOT put diazepam or barbiturates in same syringe/bag
Safety for obstetric procedures not established
Children may require head positioning, supplemental oxygen, occasional bad-valve-mask ventilatory support and measures top address laryngospasm
Use caution in patients with significant LV dysfunction, as the sympathetic stimulation may not be adequate to overcome the negative inotropic effects, resulting in deterioration
Emergence reactions
- Postanesthetic emergence reactions, manifested as dreamlike state, vivid imagery, hallucinations, and/or delirium reported in ~12%
- Least common in children younger than 15 yr, elderly older than 65 yr, or when administered IM
- May occur up to 24 hr postoperatively
- Occurrence may be decreased by using lower recommended dose in conjunction with a benzodiazepine for anesthesia induction
Pregnancy and lactation
Pregnancy category: C
Lactation: Not known if excreted in breast milk; effect on nursing infant unknown
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Ketalar (ketamine)
Mechanism of action
Produces dissociative anesthesia
Blocks NMDA receptor
Overdose may lead to panic attacks and aggressive behavior; rarely seizures, increased ICP, and cardiac arrest
Very similar in chemical makeup to PCP (phencyclidine), but it is shorter acting and less toxic
Absorption
Onset: 30 sec (IV); 3-4 min (IM)
Duration: 5-10 min (IV); 12-25 min (IM): dissociative state may last >20 min
Peak plasma concentration: 0.75 pg/mL
Metabolism
Liver
Elimination
Excretion: Urine (91%), feces (3%)
Administration
IV Incompatibilities
Additive: Barbiturates, diazepam
Syringe: Barbiturates, diazepam, doxapram
IV Compatibilities
Additive: Morphine sulfate
Syringe: Bupivacaine with fentanyl, clonidine with tetracaine, lidocaine with morphine sulfate, meperidine, morphine tartrate
Y-site: Ceftazidime, propofoL
IV Preparation
IV infusion: Prepare 1 or 2 mg/mL solution by adding 50 mg to 500 mL or to 250 mL, respectively, of D5W or Ns
IV/IM Administration
Administer IM, Or
By slow IV injection over at least 60 sec
Do not give 100 mg/mL preparation undiluted
Storage
Store at controlled room temperature
Colorless to slightly yellow solution; may darken upon prolonged exposure to light but this does not affect potency
Do not use if precipitate is present
Protect from light
