Epilepsy is a neurological disorder marked by recurrent, unprovoked seizures—sudden bursts of abnormal electrical activity in the brain. These episodes vary, from brief lapses of awareness to prolonged convulsions. Public interest in cannabis (marijuana) has grown due to its potential in managing chronic conditions, including epilepsy. This interest stems from the plant’s diverse compounds and their interactions with the body.
Understanding Cannabis Compounds and the Endocannabinoid System
Cannabis contains numerous compounds, primarily cannabidiol (CBD) and tetrahydrocannabinol (THC). THC is psychoactive, producing the “high” associated with cannabis use. CBD is non-psychoactive, meaning it does not induce intoxicating effects.
These cannabinoids interact with the human endocannabinoid system (ECS), a complex cell-signaling network found throughout the body. The ECS plays a role in regulating various bodily functions, including neurological activity, mood, appetite, and memory. It consists of endocannabinoids (molecules produced by the body), cannabinoid receptors (CB1 and CB2), and enzymes that synthesize and break down endocannabinoids.
CB1 receptors are predominantly located in the central nervous system, while CB2 receptors are found mainly in the peripheral nervous system and immune cells. While THC directly binds to both CB1 and CB2 receptors, CBD interacts with the ECS in a more indirect manner, potentially by preventing the breakdown of the body’s natural endocannabinoids or by influencing other receptors.
Therapeutic Potential for Seizure Management
Cannabidiol shows promise in managing certain forms of epilepsy, especially those resistant to conventional treatments. Clinical trials and anecdotal reports suggest CBD may reduce seizure frequency and severity.
Specifically, CBD has demonstrated effectiveness in rare and severe childhood epilepsies like Dravet syndrome and Lennox-Gastaut syndrome. The Food and Drug Administration (FDA) approved Epidiolex, a purified, plant-derived CBD oral solution, for treating seizures associated with these syndromes, and later for tuberous sclerosis complex.
The proposed mechanisms by which CBD exerts its anti-seizure effects are still being investigated but involve multiple pathways. CBD may modulate neurotransmitter activity and reduce neuronal excitability.
Research indicates that CBD can antagonize GPR55 at excitatory synapses, decreasing intracellular calcium release and reducing excitatory currents and seizure activity. Additionally, CBD may desensitize TRPV1 channels and inhibit adenosine reuptake, contributing to its anticonvulsant properties. These actions help restore the balance between excitatory and inhibitory signals in the brain, often disrupted in epilepsy.
Risks and Side Effects for Individuals with Epilepsy
Despite the therapeutic potential of cannabis compounds, individuals with epilepsy should be aware of risks and side effects. Common side effects include fatigue, drowsiness, diarrhea, and changes in appetite. For individuals managing epilepsy, concerns also arise regarding interactions with existing anti-epileptic medications (AEDs).
CBD can influence the metabolism of other drugs, potentially leading to increased or decreased levels of AEDs in the bloodstream. For instance, studies have shown that CBD can significantly interact with AEDs such as clobazam, valproate, topiramate, rufinamide, zonisamide, and eslicarbazepine. This can necessitate dosage adjustments of AEDs to maintain effectiveness and minimize side effects. Concomitant use of CBD and valproate, for example, has been associated with elevated liver enzymes, requiring careful monitoring of liver function.
Another concern is paradoxical seizure worsening, especially with unregulated products or those high in THC. Unregulated or homemade cannabis products vary significantly in composition, often containing undisclosed and inconsistent cannabinoid levels, including elevated THC. This variability, along with potential contaminants, poses health risks and can complicate seizure management.
The Role of Medical Supervision
Given the complexities of cannabis use for epilepsy, medical supervision is important. Consulting a healthcare professional before considering cannabis is advised. A doctor can provide personalized medical advice, considering an individual’s seizure type, current medications, and overall health.
Healthcare providers can help weigh benefits against risks, including drug interactions and side effects. They can also guide patients toward appropriate, regulated products. Self-medication with cannabis is discouraged due to the variable potency and purity of unregulated options, which can lead to unpredictable effects and harm. Close medical monitoring ensures safe and effective treatment, with adjustments as necessary.