Home Drug Guide Pentobarbital

Drug Guide

Generic Name

Pentobarbital

Brand Names Nembutal

Classification

Therapeutic: Sedative-Hypnotic, Anticonvulsant

Pharmacological: Barbiturate

FDA Approved Indications

  • Short-term treatment of insomnia
  • Preoperative sedation
  • Control of convulsive seizures

Mechanism of Action

Pentobarbital enhances the activity of gamma-aminobutyric acid (GABA) at GABA_A receptors, increasing chloride ion influx and causing hyperpolarization of neurons, leading to sedative, hypnotic, and anticonvulsant effects.

Dosage and Administration

Adult: Dosage varies based on indication; for sedation, typically 160-200 mg at bedtime. For preoperative sedation, 60-100 mg IV or IM or as directed by medical protocol.

Pediatric: Use and dosing must be individualized; start with lower doses, typically 1-3 mg/kg for sedation.

Geriatric: Lower doses are recommended due to increased sensitivity and decreased metabolism.

Renal Impairment: Use with caution; monitor for increased sedative effects.

Hepatic Impairment: Use with caution; metabolism may be decreased, requiring dose adjustments.

Pharmacokinetics

Absorption: Well absorbed after oral and parenteral administration.

Distribution: Widely distributed in body tissues including the brain.

Metabolism: Primarily hepatic metabolism via oxidation to inactive metabolites.

Excretion: Renal excretion of unchanged drug and metabolites.

Half Life: About 15-50 hours in adults; may be prolonged in the elderly and those with hepatic impairment.

Contraindications

  • Hypersensitivity to barbiturates or other components.
  • Porphyria.

Precautions

  • Use with caution in patients with respiratory impairment, liver disease, or a history of substance abuse.
  • Risks of dependence, overdose, and respiratory depression. Life-threatening respiratory and cardiovascular depression can occur.

Adverse Reactions - Common

  • Drowsiness (Common)
  • Dizziness (Common)
  • Gastrointestinal upset (Uncommon)

Adverse Reactions - Serious

  • Respiratory depression (Serious)
  • Hypersensitivity reactions including Stevens-Johnson syndrome (Serious)
  • Dependence and withdrawal syndrome (Serious)

Drug-Drug Interactions

  • Other CNS depressants (e.g., opioids, benzodiazepines, alcohol) increasing sedative effects and risk of respiratory depression.
  • CYP450 enzyme inducers or inhibitors affecting metabolism.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor respiratory and cardiovascular status, level of consciousness, and signs of dependence.

Diagnoses:

  • Impaired gas exchange
  • Risk for dependence
  • Risk for injury related to sedation.

Implementation: Administer as prescribed, monitor vitals and mental status, and educate about dependence and overdose risks.

Evaluation: Assess for therapeutic effect, side effects, and signs of toxicity.

Patient/Family Teaching

  • Do not operate machinery or drive until effects are known.
  • Avoid alcohol and other CNS depressants.
  • Report signs of respiratory depression, excessive sedation, or allergic reactions.
  • Do not suddenly stop medication to avoid withdrawal.

Special Considerations

Black Box Warnings:

  • Risks of respiratory depression, somnolence, coma, and death when used with other CNS depressants or in overdose.

Genetic Factors: Patients with a history of porphyria should avoid.

Lab Test Interference: May interfere with certain laboratory tests, monitor accordingly.

Overdose Management

Signs/Symptoms: Confusion, ataxia, nystagmus, respiratory depression, coma, hypotension.

Treatment: Supportive care including airway management, monitor vital signs, activated charcoal if within an hour of ingestion, and hemodialysis in severe cases.

Storage and Handling

Storage: Store in a tightly closed container at room temperature away from light and moisture.

Stability: Stable under recommended storage conditions for the duration of the expiration date.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.