Thiopental (Pentothal)

Category:

  • General anesthetic

Description:

  • Barbiturate general anesthetic

Indications:

  • General anesthesia

  • Increased intracranial pressure

  • Narcoanalysis

  • Sedation induction

  • Status epilepticus

Contraindications:

  • Acute porphyria

  • Porphyria history

Precautions:

  • Pregnancy category C; do not breast feed

  • Hepatic disease

  • Preexisting respiratory depression

Adverse Reactions (Side Effects):

  • CV: cardiac disease, hypertension, hypotension, myxedema, peripheral vascular disease

  • MISC: respiratory insufficiency, anemia, adrenal insufficiency, shock, uremia

Dosage:

Administered intravenously, rectally

  • General anesthesia induction and maintenance:

    • Adult: 

      • IV 50-100mg initially, intermittent dose 20-40 seconds intervals, or 3-5 mg/kg IV as single dose. 

      • May give additional doses up to 500mg max. 

      • Once anesthesia established, 25-50mg each time patient moves.  

      • Alternatively, a 0.2%-0.4% solution can be used as continuous drip; adjust drip rate as necessary.

    • Child 1-12 years: 

      • IV 5-6 mg/kg over 10-60 minutes, followed by maintenance dose 1 mg/kg as needed

    • Infants: 

      • IV 5-8 mg/kg over 10-60 minutes

    • Neonates: 

      • IV 3-4 mg/kg over 10-60 minutes

  • Preanesthetic induction: 

    • Adult: 30 mg/kg PR prior to anesthesia

  • Basal narcosis: 

    • Adult: 9 mg/kg PR, max 3-4g for adult > 90 kg

  • Child: 

    • 9 mg/kg PR, max 1-1.5g for child > 34 kg

  • Treatment of increased intracranial pressure: 

    • Adult: 

      • IV bolus 1.5-3.5 mg/kg, ventilation must be provided

  • Treatment of status epilepticus: 

    • Adult: 

      • IV 50-125mg as soon as possible after onset of seizures,  

      • Seizures caused by local anesthetics may require up to 250mg IV over 10 minutes

  • Narcoanalysis: 

    • Adult: IV slow injection 100 mg/min (4ml/min of a 2.5% solution) with patient counting backwards from 100.  

    • Stop infusion after patient becomes confused, but before sleep.  

    • All patients to return to semidrowsy state where conversation is coherent.  

    • Alternatively, a 0.2% solution in D5W may be given by rapid IV drip not greater than 50 ml/min

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