Nurses Compass
Drug Guide
Ezogabine
Classification
Therapeutic: Anticonvulsant, Adjunctive therapy in seizures
Pharmacological: Potassium channel opener
FDA Approved Indications
- Partial-onset seizures in adults
Mechanism of Action
Ezogabine selectively opens neuronal voltage-gated potassium channels (KCNQ2-5), stabilizing neuronal membrane potential and reducing neural hyperexcitability, thereby decreasing seizure activity.
Dosage and Administration
Adult: Start with 600 mg per day in divided doses, titrating up to a maximum of 2,400 mg per day based on response and tolerability.
Pediatric: Not approved for pediatric use.
Geriatric: Monitor closely due to increased sensitivity to side effects; dose adjustments based on response.
Renal Impairment: Adjust dose according to renal function; specific guidelines recommend caution and dose adjustments in renal impairment.
Hepatic Impairment: Use with caution; no specific dose adjustment established.
Pharmacokinetics
Absorption: Well-absorbed orally.
Distribution: Varies; extensively bound to plasma proteins.
Metabolism: Partially metabolized in the liver; primary pathway involves glucuronidation.
Excretion: Excreted mainly in urine as metabolites.
Half Life: Approximately 7-11 hours.
Contraindications
- Known hypersensitivity to ezogabine or any component of the formulation.
Precautions
- History of QT prolongation, suicidal ideation or behavior, vision disturbances, or urinary retention. Regular ophthalmologic and urinary assessments recommended.
Adverse Reactions - Common
- Dizziness (Common)
- Somnolence (Common)
- Fatigue (Common)
- Diplopia or blurred vision (Common)
Adverse Reactions - Serious
- QT prolongation leading to arrhythmias (Serious (rare))
- Red-orange coloration of the skin and urine, which is harmless but can be alarming (Common)
- Psychosis or hallucinations (Uncommon)
- Suicidal thoughts or behavior (Uncommon)
Drug-Drug Interactions
- CYP3A4 inhibitors or inducers may affect ezogabine levels
Drug-Food Interactions
- No significant food interactions reported
Drug-Herb Interactions
- Limited data; caution with herbal products affecting CNS or QT interval
Nursing Implications
Assessment: Monitor seizure frequency, mental status, vision, and urinary function.
Diagnoses:
- Risk for injury related to dizziness or vision impairment.
- Risk for altered mental status.
Implementation: Administer as prescribed, monitor for adverse effects, educate on potential signs of toxicity.
Evaluation: Assess seizure control, adverse reactions, and adherence.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report any vision changes, mood alterations, or urinary issues immediately.
- Be aware of potential discoloration of skin and urine.
- Avoid sudden discontinuation.
- Follow-up appointments for eye and urinary assessments.
Special Considerations
Black Box Warnings:
- Potential for retinal abnormalities leading to vision loss; requires baseline and periodic eye examinations.
Genetic Factors: No specific genetic considerations documented.
Lab Test Interference: May affect urine color assessments; no significant interference with laboratory tests.
Overdose Management
Signs/Symptoms: Dizziness, drowsiness, hallucinations, QT prolongation, seizures.
Treatment: Supportive care; manage seizures with standard protocols; monitor cardiac status; activated charcoal if within appropriate time window.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F).
Stability: Stable under recommended storage conditions.