Home Drug Guide Gabapentin Enacarbil

Drug Guide

Generic Name

Gabapentin Enacarbil

Brand Names Horizant

Classification

Therapeutic: Nerve Pain Agent, Anticonvulsant

Pharmacological: Prodrug of Gabapentin, Calcium Channel Alpha-2-Delta Ligand

FDA Approved Indications

Postherpetic Neuralgia
Restless Legs Syndrome

Mechanism of Action

Gabapentin Enacarbil is a prodrug that is converted to gabapentin, which binds to the alpha-2-delta subunit of voltage-gated calcium channels in the central nervous system, decreasing excitatory neurotransmitter release and calming nerve overactivity.

Dosage and Administration

Adult: Initially 600 mg once daily at bedtime or in the morning, titrating as needed up to 1200-2400 mg daily in divided doses.

Pediatric: Not approved for pediatric use.

Geriatric: Start at lower end of dosing range; monitor renal function closely.

Renal Impairment: Dose adjustment needed based on creatinine clearance, typically starting at lower doses and titrating carefully.

Hepatic Impairment: No specific adjustment recommended.

Pharmacokinetics

Absorption: Absorbed rapidly with high bioavailability (~68%).

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

Metabolism: Converted to gabapentin via hydrolysis; minimal metabolism of gabapentin itself.

Excretion: Excreted unchanged in urine.

Half Life: Approximately 7 hours.

Contraindications

Hypersensitivity to gabapentin or related compounds.

Precautions

Renal impairment (dose adjustment necessary).
Use with caution in patients with depression or suicidal ideation.
Potential for CNS depression, caution when operating machinery.

Adverse Reactions - Common

Dizziness (Common)
Somnolence (Common)
Headache (Common)

Adverse Reactions - Serious

Angioedema (Rare)
Suicidal thoughts or behavior (Monitor due to as with other anticonvulsants)

Drug-Drug Interactions

Opioids (enhanced CNS depression)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for signs of CNS depression, suicidal ideation, and effectiveness in reducing neuralgia or restless legs symptoms.

Diagnoses:

Risk for injury related to dizziness or somnolence.
Risk for suicidal ideation.

Implementation: Administer with food to reduce dizziness and gastrointestinal upset. Monitor renal function regularly.

Evaluation: Assess pain relief or alleviation of restless legs symptoms, and monitor for adverse effects.

Patient/Family Teaching

Take medication exactly as prescribed.
Notify healthcare provider of any mood changes or suicidal thoughts.
Report any swelling, difficulty breathing, or severe allergic reactions.

Special Considerations

Black Box Warnings:

Potential for mood or behavior changes leading to suicidal thoughts and behaviors.

Genetic Factors: None established.

Lab Test Interference: None known.

Overdose Management

Signs/Symptoms: Dizziness, somnolence, nystagmus, slurred speech.

Treatment: Supportive care, airway management, hemodialysis may be considered as gabapentin is excreted renally.

Storage and Handling

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

Stability: Stable until expiration date printed on package.