Drug reference

methohexital

Barbiturate · Anesthetic

BarbiturateAnesthetic

CDSCO approved

EXCRETION

—

not curated

INTERACTIONS

7 major

SEVERE in our sources

PREGNANCY

—

not curated

Top interactionssee all 7 →

EthanolSevereDatabaseDDInter
IsocarboxazidSevereDatabaseDDInter
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SelegilineSevereDatabaseDDInter

Mechanism

Barbiturates enhance GABA-mediated inhibitory transmission throughout the CNS. They bind to an allosteric site on the GABAA receptor, increasing the mean open time of the GABA-activated Cl– channel. At higher concentrations, barbiturates directly activate channel opening.

Indications

Induction and maintenance of anesthesiaanesthesia for electroconvulsive therapy

Dosing

Adult: 1.0–1.5 mg/kg for induction

Pharmacokinetics

Onset

rapid

Duration

5–7 min of anesthesia

Half-life

3–5

Metabolism

primarily eliminated by hepatic metabolism

Contraindications

patients with acute intermittent or variegate porphyria

Side effects

Common

pain on injectionexcitatory symptoms on induction (cough, hiccup, muscle tremors, twitching, hypertonus)hiccupsdose-dependent decrease in blood pressureincreased heart rate (compensatory)responsive depressionwheezing (higher incidence in asthmatics, attributed to histamine release)

Serious