Home Drug Guide Cannabidiol

Drug Guide

Generic Name

Cannabidiol

Brand Names Epidiolex

Classification

Therapeutic: Anticonvulsant, Neurological disorder treatment

Pharmacological: Cannabinoid

FDA Approved Indications

Lennox-Gastaut syndrome in patients age 2 years and older
Dravet syndrome in patients age 1 year and older

Mechanism of Action

Cannabidiol modulates several non-cannabinoid receptors and ion channels, leading to anticonvulsant effects, though its exact mechanism in seizure control is not fully understood.

Dosage and Administration

Adult: Start at 2.5 mg/kg twice daily, titrate up to 10-20 mg/kg twice daily based on response and tolerability.

Pediatric: Initial dose generally 2.5 mg/kg twice daily; titrate gradually.

Geriatric: Data limited; use with caution, start at lower doses, monitor closely.

Renal Impairment: Adjust dosing based on clinical response; no specific guidelines, but cautious titration recommended.

Hepatic Impairment: Liver function should be monitored; dose adjustments may be necessary, especially with concomitant hepatic impairment.

Pharmacokinetics

Absorption: Well absorbed orally, with food increasing bioavailability.

Distribution: Widely distributed; crosses blood-brain barrier.

Metabolism: Primarily metabolized in the liver via CYP2C19, CYP3A4 enzymes.

Excretion: Mainly via feces, minor renal excretion.

Half Life: Approximately 11-20 hours.

Contraindications

Hypersensitivity to cannabidiol or any component of the formulation.

Precautions

Liver function abnormalities; monitor ALT and AST, especially at initiation and dose escalation.
Use with caution in patients with a history of suicidal ideation or behavior.
Potential for drug interactions, especially with CYP450 substrate drugs.

Adverse Reactions - Common

Somnolence (Most common, dose-related)
Decreased appetite (Common)
Diarrhea (Common)
Transaminase elevations (Less common, but significant)
Fatigue (Common)

Adverse Reactions - Serious

Liver enzyme elevation leading to hepatitis (Rare, but serious)
Allergic reactions including rash, or hypersensitivity (Rare)

Drug-Drug Interactions

CYP450 inhibitors or inducers (e.g., ketoconazole, rifampin) can affect cannabidiol levels.
Other sedatives or CNS depressants may have additive effects.

Drug-Food Interactions

High-fat meals increase absorption.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor liver function tests (ALT, AST) before and during treatment; assess seizure frequency.

Diagnoses:

Risk for injury related to seizure activity, sedation.
Impaired liver function.

Implementation: Start at low dose, titrate slowly. Educate patients on potential side effects and interactions.

Evaluation: Monitor seizure frequency, adverse reactions, and liver function to assess drug efficacy and safety.

Patient/Family Teaching

Take medication exactly as prescribed, with or without food.
Report side effects such as mood changes, dizziness, or signs of liver issues.
Avoid operating machinery until you know how cannabidiol affects you.
Inform healthcare provider about all other medications being taken.

Special Considerations

Black Box Warnings:

Hepatotoxicity, including elevations in liver enzymes and potential liver injury.
Summary of product characteristics emphasizes caution in use, especially in patients with existing liver disease.

Genetic Factors: Metabolism via CYP2C19 may influence drug levels; genetic polymorphisms may affect response.

Lab Test Interference: May elevate liver enzymes; monitor accordingly.

Overdose Management

Signs/Symptoms: Drowsiness, sedation, hypotension, diarrhea.

Treatment: Supportive care; activated charcoal if ingestion is recent; monitoring and symptomatic treatment.

Storage and Handling

Storage: Store at 68°F to 77°F (20°C to 25°C), away from heat, moisture, and light.

Stability: Stable when stored properly, check manufacturer recommendations.