Alfentanil
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Drug reference
barbiturates
Barbiturate · Anxiolytic
BarbiturateAnxiolytic
CDSCO approved
EXCRETION
—
not curated
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
—
not curated
Top interactionssee all 12 →
- AlfentanilSevereTextbookKDT 7e · p401
- AntihistaminesSevereTextbookKDT 7e · p401
- BuprenorphineSevereTextbookKDT 7e · p401
- Cns DepressantsSevereTextbookG&G 14e
Mechanism
Barbiturates facilitate the activity of GABAA receptors at allosteric sites that are distinct from the benzodiazepine binding site.
Indications
AnxiolyticsAnticonvulsantsHypnoticsAnti-migraine drugsAnesthetics in surgical settings
Pharmacokinetics
Metabolism
Barbiturates are oxidized by microsomal enzymes and induce CYP3A isoenzymes and CYP2B1.
Contraindications
- Combined with other CNS depressants
Side effects
Serious
- Overdose death
- Increased fatality when combined with other CNS depressants
- acute intermittent porphyria
- increased brain sensitivity in cirrhotics (can produce coma at normal doses)
Drug interactions
Antihistamines
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Buprenorphine
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Cns Depressants
Severe
Textbook
Increased fatality.
Avoid combination.
Source: G&G 14e
Codeine
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Disulfiram
Severe
Textbook
Increased barbiturate levels, potentially leading to increased CNS depression or toxicity.
Monitor for increased CNS depression. Dose adjustment of barbiturates may be necessary.
Source: G&G 14e · p528
Fentanyl
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Hydrocodone
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Methadone
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Methylnaltrexone
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Morphine
Severe
Textbook
Exaggerated CNS depression.
Source: KDT 7e · p401
Muscle Relaxants
Severe
Textbook
Precipitation, potentially blocking the intravenous line.
Barbiturates should be allowed to clear from the intravenous line prior to injection of a muscle relaxant.
Source: G&G 14e · p481
Related guidelines
Other Barbiturate drugs
Ask House about barbiturates
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e·Verified: 2026-05-10 · House clinical team