Epilepsy & Seizure Disorders

Cannabis-Based Treatment Guide

Epilepsy represents the strongest evidence base for cannabis medicine. CBD (cannabidiol) received FDA approval in 2018 as Epidiolex for Dravet syndrome and Lennox-Gastaut syndrome — the first plant-derived cannabis medicine approved by the FDA. Multiple RCTs demonstrate significant seizure reduction in treatment-resistant epilepsy.

FDA Status: Epidiolex approved 2018
Primary Cannabinoid: CBD only (no THC)
Evidence Level: Strong (RCT data)
Key Caution: Multiple drug interactions

Critical Warning: Epilepsy treatment must be managed by a neurologist. Never stop antiepileptic medications without medical supervision. CBD has significant drug interactions with common AEDs requiring dose adjustments and monitoring.

Anticonvulsant Mechanisms of CBD

GPR55 Antagonism

CBD blocks GPR55 receptors, which when activated increase neuronal excitability. GPR55 antagonism reduces the hyperexcitability that drives seizures.

TRPV1 Desensitization

CBD activates and then desensitizes TRPV1 channels, reducing neuronal firing rates. TRPV1 overactivation contributes to seizure generation in several epilepsy syndromes.

Sodium Channel Modulation

CBD inhibits voltage-gated sodium channels (Nav1.1, Nav1.2), reducing the rapid firing of action potentials that characterizes seizure activity.

GABAergic Enhancement

CBD positively modulates GABA-A receptors, enhancing inhibitory neurotransmission and raising the seizure threshold.

Adenosine Reuptake Inhibition

CBD inhibits adenosine reuptake, increasing adenosine levels. Adenosine is a potent endogenous anticonvulsant that suppresses neuronal excitability.

FDA-Approved Indications

Epidiolex (CBD oral solution) is FDA-approved for:

  • Dravet Syndrome — ages 1 and older
  • Lennox-Gastaut Syndrome — ages 1 and older
  • Tuberous Sclerosis Complex — ages 1 and older

Epidiolex is the only FDA-approved cannabis-derived medication. It is a Schedule V controlled substance.

Epilepsy Types with Evidence
  • Dravet Syndrome
    FDA-approved (Epidiolex)
  • Lennox-Gastaut Syndrome
    FDA-approved (Epidiolex)
  • Tuberous Sclerosis Complex
    FDA-approved (Epidiolex)
  • CDKL5 Deficiency Disorder
    Strong — open-label trials
  • Aicardi Syndrome
    Moderate — case series
  • Treatment-resistant focal epilepsy
    Moderate — open-label data
Last Reviewed: April 2026

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