Home Drug Guide Vigabatrin

Drug Guide

Generic Name

Vigabatrin

Brand Names Sabril, Vigadrone, Vigpoder, Vigafyde

Classification

Therapeutic: Anticonvulsant, Glutamate Antagonist

Pharmacological: GABA Transaminase Inhibitor

FDA Approved Indications

  • Partial onset seizures in adults and children ≥1 month with epilepsy
  • Infantile spasms in children aged 1 month and older

Mechanism of Action

Vigabatrin irreversibly inhibits gamma-aminobutyric acid (GABA) transaminase, leading to increased levels of GABA in the brain, which enhances inhibitory neurotransmission and suppresses seizure activity.

Dosage and Administration

Adult: Typically, 1 gram twice daily. Dose adjustments based on response and tolerability.

Pediatric: Starting dose usually 50-100 mg/kg/day divided twice daily, titrated up based on efficacy and tolerability.

Geriatric: Dose adjustment may be necessary; start at lower doses and titrate carefully.

Renal Impairment: Dose reduction is recommended in renal impairment; specific adjustments depend on degree of impairment.

Hepatic Impairment: No specific adjustment; caution advised as data are limited.

Pharmacokinetics

Absorption: Well absorbed orally with peak plasma concentrations in 1-2 hours.

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

Metabolism: Minimal hepatic metabolism; most is excreted unchanged by the kidneys.

Excretion: Primarily excreted unchanged in urine.

Half Life: Approximately 26 hours, allowing for twice daily dosing.

Contraindications

  • Hypersensitivity to vigabatrin or its components

Precautions

  • History of psychosis or depression; risk of visual field loss; monitor mental health; cautious use in renal impairment.

Adverse Reactions - Common

  • Somnolence (Common)
  • Dizziness (Common)
  • Fatigue (Common)

Adverse Reactions - Serious

  • Visual field constriction (Serious (can be permanent))
  • Psychiatric effects (depression, psychosis) (Serious)
  • Peripheral vision loss (Serious)

Drug-Drug Interactions

  • Other CNS depressants (additive sedative effects)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Baseline visual fields, mental health status, renal function.

Diagnoses:

  • Risk for visual impairment related to visual field constriction.
  • Risk for depression or psychiatric disturbance.

Implementation: Monitor visual fields regularly (e.g., every 3 months).

Evaluation: Assess for visual changes, mental health status, and seizure control.

Patient/Family Teaching

  • Report new visual disturbances immediately.
  • Do not stop medication abruptly.
  • Avoid driving or operating machinery if visual changes occur.
  • Discuss mental health status regularly.

Special Considerations

Black Box Warnings:

  • Persistent vision loss due to bilateral visual field constriction.
  • Potential for severe mental health disturbances, including psychosis and depression.

Genetic Factors: Genetic testing is not routinely required but consider in patients with family history.

Lab Test Interference: No known interference.

Overdose Management

Signs/Symptoms: Excessive sedation, hypotension, coma (rare).

Treatment: Supportive care; no specific antidote. Hemodialysis may be considered in severe cases to enhance elimination.

Storage and Handling

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

Stability: Stable for the duration of the expiry date provided.

🛡️ 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.