Brevital (Methohexital) Administration Rate
No, Brevital does not need to be injected over a full minute—the FDA-approved administration rate for induction is approximately 1 mL of 1% solution every 5 seconds, which translates to roughly 10-15 seconds for a typical induction dose of 50-120 mg. 1
FDA-Approved Administration Guidelines
Induction Dosing and Rate
- Administer 1% solution (10 mg/mL) at a rate of approximately 1 mL per 5 seconds for induction of anesthesia 1
- The typical induction dose of 70 mg (7 mL of 1% solution) would therefore be administered over approximately 35 seconds 1
- The dose range of 50-120 mg (1-1.5 mg/kg in adults) provides anesthesia for 5-7 minutes 1
Critical Safety Requirements
- Use only 1% concentration or lower for intravenous administration—higher concentrations markedly increase the incidence of muscular movements and irregularities in respiration and blood pressure 1
- Facilities for assisting ventilation and administering oxygen must be immediately available 1
- Age- and size-appropriate resuscitative equipment (intubation equipment, cardioversion equipment, oxygen, suction, and secure IV line) must be immediately available 1
- Personnel qualified in resuscitation must be present, as cardiorespiratory arrest may occur 1
Clinical Context and Duration of Action
Pharmacokinetics
- Maximal brain concentrations are achieved within 30 seconds after IV injection 2
- Duration of action after a single dose is 4-7 minutes due to rapid redistribution to other tissues 2
- Recovery times are short and uneventful, with patients typically cleared for discharge in under 35 minutes 3
Maintenance Dosing
- Intermittent boluses: 20-40 mg (2-4 mL of 1% solution) every 4-7 minutes as required 1
- Continuous infusion: 0.2% solution at approximately 3 mL/minute (1 drop/second), with rate individualized for each patient 1
- For conscious sedation via infusion, start at 50 mcg/kg/min and increase as needed to 75 mcg/kg/min 3
Common Pitfalls to Avoid
Administration Errors
- Never use concentrations higher than 1% for IV induction—this significantly increases adverse effects 1
- Do not mix Brevital with acid solutions (atropine sulfate, metocurine iodide, succinylcholine chloride) in the same syringe, as precipitation may occur 1
- Do not confuse the rapid administration rate (1 mL/5 seconds) with slower rates used for other sedatives 1
Monitoring Requirements
- Observe patients carefully during and after administration for cardiorespiratory depression 1
- Be prepared for potential adverse effects including apnea, cardiovascular depression, laryngospasm, hiccough (noted in 4 of 20 patients in one study), and shivering 2, 3
- Monitor for mild increases in heart rate (<15% increase) 3