Thiopen

• Induction of General Anesthesia: Used to rapidly induce anesthesia before maintenance with other agents.
• Procedural Sedation: Short diagnostic or surgical procedures requiring hypnosis.
• Emergency Treatment of Status Epilepticus: When benzodiazepines are ineffective or unavailable.
• Reduction of Increased Intracranial Pressure: In severe brain injury or cerebral edema, to decrease cerebral metabolic demand.
• Barbiturate Coma: Induction of coma in patients with refractory increased intracranial pressure or severe traumatic brain injury.

• Route: Intravenous (IV) administration only.
• Adults:
• Anesthesia Induction: 3–5 mg/kg IV bolus over 10–30 seconds.
• Status Epilepticus: 3–5 mg/kg IV bolus; may repeat or initiate continuous infusion titrated to effect.
• Barbiturate Coma: Loading dose 3–5 mg/kg IV; maintenance by continuous infusion.
• Pediatrics: Same dosing as adults (3–5 mg/kg IV).
• Elderly: Start at lower doses due to increased sensitivity and slower metabolism.
• Hepatic Impairment: Use cautiously; dose reduction may be necessary.
• Renal Impairment: No specific adjustments, but monitor clinical response.

Thiopental sodium is an ultra-short-acting barbiturate that enhances the inhibitory effects of gamma-aminobutyric acid (GABA) at the GABA_A receptor. It prolongs the opening of chloride ion channels, causing hyperpolarization of neuronal membranes and resultant CNS depression. This leads to rapid induction of hypnosis, sedation, and anticonvulsant effects by depressing neuronal excitability.

• Absorption: Administered IV with immediate onset (within 30 seconds).
• Distribution: Rapidly distributes to highly perfused tissues, especially the brain.
• Metabolism: Extensively metabolized in the liver by CYP450 enzymes.
• Half-life: Redistribution half-life 5–15 minutes; elimination half-life 3–8 hours.
• Excretion: Metabolites eliminated primarily via the kidneys.

• Pregnancy: FDA Category C — Animal studies have shown adverse effects; use only if benefits justify risks.
• Lactation: Excreted in breast milk in small amounts; caution advised.

• Primary Class: Barbiturate
• Subclass: Ultra-short-acting intravenous anesthetic

• Hypersensitivity to barbiturates.
• Acute intermittent porphyria.
• Severe respiratory depression without ventilatory support.
• Shock or severe hypotension.
• Status asthmaticus.

• May cause profound respiratory depression and apnea; resuscitation equipment must be immediately available.
• Risk of cardiovascular depression and hypotension, especially in hypovolemic or elderly patients.
• Caution in patients with increased intracranial pressure, hepatic or renal impairment.
• Potential for dependence and abuse; use only in controlled settings.
• Monitor for rare anaphylactic reactions during administration.

• Common: Respiratory depression, hypotension, drowsiness, injection site pain.
• Serious/Rare: Anaphylaxis, bronchospasm, cardiac arrhythmias, prolonged sedation.

• Additive CNS and respiratory depression with other depressants (opioids, benzodiazepines, alcohol).
• CYP450 inducers (e.g., rifampin, phenytoin) may reduce thiopental effectiveness.
• CYP450 inhibitors (e.g., cimetidine) may increase toxicity risk.
• May alter anticoagulant effects of warfarin.

• Use is decreasing in favor of agents with improved safety profiles.
• Emphasis on airway management and monitoring during use.
• No major changes in dosing guidelines; safety protocols stressed.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from light and moisture.
• Do not freeze.
• Use aseptic technique; discard any unused solution after opening.