Home Drug Guide Metharbital

Drug Guide

Generic Name

Metharbital

Brand Names Gemonil

Classification

Therapeutic: Anticonvulsant, Antiepileptic

Pharmacological: Barbiturate

FDA Approved Indications

  • Epilepsy

Mechanism of Action

Enhances GABA-mediated inhibitory neurotransmission by increasing the duration of chloride channel opening at GABA-A receptors, producing sedative and anticonvulsant effects.

Dosage and Administration

Adult: Initial dose: 100-150 mg daily, divided into 2-4 doses. Adjust based on response and tolerability.

Pediatric: Doses vary; typically started with 5-8 mg/kg/day, divided into 2-4 doses, titrated based on clinical response.

Geriatric: Begin at lower end of dosing range, monitor closely for sedation and respiratory depression.

Renal Impairment: Use with caution; dose adjustments may be necessary.

Hepatic Impairment: Use with caution; hepatic metabolism may be impaired, affecting dosing.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed, crosses the blood-brain barrier.

Metabolism: Metabolized in the liver via hepatic enzymes.

Excretion: Excreted primarily in urine.

Half Life: Approximately 6-12 hours, variable depending on individual factors.

Contraindications

  • Hypersensitivity to barbiturates.
  • Porphyria.

Precautions

  • Use with caution in respiratory insufficiency, hepatic impairment, and in pregnancy (category D).
  • Risk of dependence and abuse.

Adverse Reactions - Common

  • Sedation, drowsiness (Common)
  • Impaired cognition, ataxia (Common)

Adverse Reactions - Serious

  • Respiratory depression (Rare)
  • CNS depression leading to coma (Rare)
  • Hypersensitivity reactions (Rare)

Drug-Drug Interactions

  • Other CNS depressants (additive sedative effects).
  • Bone marrow suppressants.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor anticonvulsant effectiveness, signs of toxicity, liver function, respiratory function.

Diagnoses:

  • Risk for injury due to sedation or ataxia.
  • Impaired breathing.

Implementation: Administer with meals if GI upset occurs; monitor serum levels if applicable.

Evaluation: Assess for seizure control, adverse reactions, and toxicity.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Avoid alcohol and CNS depressants.
  • Report signs of toxicity or allergic reactions.
  • Use caution to prevent falls and injuries.

Special Considerations

Black Box Warnings:

  • Potential for respiratory depression, dependence, and abuse.

Genetic Factors: Poor metabolism in some populations may affect drug levels.

Lab Test Interference: May alter liver function tests.

Overdose Management

Signs/Symptoms: Confusion, coma, respiratory depression, pin-point pupils.

Treatment: Supportive care, airway management, activated charcoal if recent ingestion, and potentially dialysis in severe cases.

Storage and Handling

Storage: Store at room temperature away from moisture and heat.

Stability: Stable for 2-3 years under proper conditions.

🛡️ 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.