CBD for epilepsy and seizures: what medicine says and why CBD is legal

Among all areas of CBD application, epilepsy has the strongest clinical support. In 2018, the FDA approved Epidiolex — a pure CBD-based drug — for the treatment of two rare, severe forms of epilepsy: Dravet syndrome and Lennox-Gastaut syndrome. This is a historic moment: the first cannabis-derived drug registered by an American regulator in history. In Poland, the path to Epidiolex is possible, though not easy. This article explains the clinical application of CBD in epilepsy, what key studies say, how access works in Poland, and how Epidiolex differs from CBD supplements available in stores.

KEY INFORMATION
• Devinsky et al. (NEJM, 2017) demonstrated a 38.9% reduction in seizures vs 13.3% placebo in a randomized CBD study in Dravet syndrome.
• The FDA approved Epidiolex (100 mg CBD/ml) in June 2018; the EMA — in 2019 for the EU, including Poland.
• CBD in epilepsy works by blocking sodium channels, GPR55 receptors, and modulating glutamate release — mechanisms different from typical anticonvulsants.
• Supplemental CBD oils are not medications and do not have documented clinical efficacy in epilepsy — they do not replace neurological treatment.

Epidiolex i FDA 2018 – co to zmienia dla CBD globalnie?

June 2018 was a groundbreaking moment in the history of cannabis medicine. The FDA (Food and Drug Administration) approved Epidiolex — a preparation containing 100 mg/ml of purified cannabidiol — as a first-line treatment for seizures in Dravet syndrome and Lennox-Gastaut syndrome in patients from 2 years of age. A year later, in 2019, the EMA (European Medicines Agency) issued a positive opinion for Epidiolex — paving the way for its use in EU countries, including Poland.

Why is this decision historic? For the first time, a top-tier regulator recognized a cannabis-derived drug as medically justified, safe, and effective for a specific indication. At the same time, it deconstructed the narrative that "cannabis is just a drug" — the FDA does not approve substances without solid clinical data confirming safety and efficacy.

An important note for Polish readers: Epidiolex is not identical to CBD supplements available in stores. It is a pharmaceutical preparation with strictly controlled purity (>98% CBD, no THC), standardized dosage, and rigorously studied pharmacokinetics. CBD oils available as supplements have different concentrations, different compositions, and have not undergone clinical trials appropriate for medications — they cannot be used as a substitute for Epidiolex in the treatment of epilepsy.

Key studies – Devinsky 2017 and what has really been proven.

Study Devinsky i wsp. opublikowane w New England Journal of Medicine (2017) This is one of the most important clinical studies regarding CBD in medicine. It was a randomized, double-blind, placebo-controlled phase III study involving 120 patients with Dravet syndrome — treatment-resistant childhood epilepsy.

The results were clear: in patients receiving CBD (20 mg/kg body weight/day for 14 weeks), the median reduction in seizure frequency was 38.9% compared to 13.3% in the placebo group (p=0.01). 5% of patients in the CBD group achieved complete seizure freedom, while none in the placebo group did. The effect was statistically significant and clinically meaningful — a 38.9% reduction in seizures for children with previously intractable epilepsy represents a substantial improvement in quality of life.

A parallel study on patients with Lennox-Gastaut syndrome — Thiele i wsp. (Lancet, 2018) — showed a reduction in atonic seizures (drop attacks) of 43.9% with CBD compared to 21.8% with placebo. Together, both studies formed the basis for the registration of Epidiolex by the FDA.

For completeness: CBD did not completely eliminate seizures in most patients — the reduction was significant but did not mean a cure. Epilepsy in Dravet and Lennox-Gastaut syndromes is a chronic condition requiring long-term treatment. However, even a 30–40% reduction in seizures for a child who previously had several seizures a week is a change that can radically improve the patient's functioning and safety.

The mechanism of action of CBD in epilepsy – why it is not a 'typical' medication

Most antiepileptic drugs work through one of several well-known mechanisms: blocking sodium channels (phenytoin, carbamazepine, lamotrigine), enhancing GABA signaling (benzodiazepines, phenobarbital, valproate), blocking calcium channels, or modulating SV2A (levetiracetam). CBD has a unique, multi-faceted mechanism that distinguishes it from these classes.

The first mechanism is the blockade of voltage-dependent sodium channels — similar to phenytoin, but with different specificity for subunits. These channels are responsible for the rapid depolarization of neurons during a seizure; their blockade stabilizes the membrane and hinders the propagation of discharges.

The second mechanism: antagonism of GPR55 receptors. GPR55 is an orphan receptor that, when activated by LPS, stimulates neuronal excitotoxicity. CBD blocks GPR55, reducing the susceptibility of neurons to excessive activation. This mechanism may be particularly important in inflammatory epilepsy.

The third mechanism: modulation of TRPV1 (vanilloid) receptors. Activation of TRPV1 by CBD leads to desensitization of the channels, which reduces the release of glutamate — the main excitatory neurotransmitter in a seizure. The fourth mechanism: an indirect effect through the endocannabinoid system — CBD inhibits the breakdown of anandamide, which may enhance endogenous anticonvulsant mechanisms via CB1. Szaflarski i wsp. (Epilepsy Behavior, 2018) They reviewed these mechanisms and emphasized that CBD is "pluripharmacological" — its action through multiple parallel pathways may explain its effectiveness in drug-resistant epilepsies.

Dravet and Lennox-Gastaut Syndromes – what are these diseases?

It is worth explaining why these two syndromes were the target of the first registrations of Epidiolex. Not because CBD does not work on other epilepsies — but because they are diseases with the greatest medical need and the most dramatic course.

Dravet Syndrome (formerly severe myoclonic epilepsy of infancy) is a rare genetic disorder resulting from a mutation in the SCN1A gene coding for the sodium channel. Seizures begin in the first year of life — often febrile — and gradually become polymorphic, occurring even a dozen times a day. Classic antiepileptic drugs are often ineffective or paradoxically exacerbate seizures. Mortality in Dravet is elevated (SUDEP — sudden unexpected death in epilepsy). It is estimated that several hundred children with this diagnosis live in Poland.

Lennox-Gastaut Syndrome is a severe epileptic encephalopathy characterized by polymorphic seizures (atonic, tonic, absence), intellectual disability, and a characteristic EEG pattern. Atonic seizures (drop attacks) cause sudden falls and are particularly dangerous. Treatment is challenging — most patients require polytherapy and still do not achieve full seizure control.

Both syndromes are classic examples of "drug-resistant epilepsy" — clinically defined as a lack of seizure control after at least two appropriately chosen and dosed antiepileptic drugs. For these patients, Epidiolex has opened a new therapeutic option after decades of lack of significant progress.

Targeted import of Epidiolex in Poland – what does the access pathway look like?

Epidiolex is not routinely available in Polish pharmacies — it has not yet received reimbursement from the NFZ. However, since 2019, it can be used in Poland through the targeted import procedure (based on Article 4 of the Pharmaceutical Law), which allows for the import of drugs registered by the EMA but not commercially available in Poland.

What does this pathway look like in practice? A parent or legal guardian of a child diagnosed with Dravet or Lennox-Gastaut approaches a neurologist specializing in pediatric epilepsy. The neurologist issues a request for targeted import, which is sent to the Ministry of Health or the Chief Pharmaceutical Inspector. After obtaining approval, a specialized pharmacy or pharmaceutical wholesaler imports the product from abroad (usually from the UK or Germany). The cost of therapy with Epidiolex ranges from several to several thousand zlotys per month — which means that for most families without support, it is inaccessible. Patient associations (e.g., Fundacja Mam Epilepsję, Fundacja Gajusz) run support programs. Some neurologists may also indicate other channels — it is worth asking.

Dlaczego CBD jest legalne? Historia prawna kannabidiolu w Polsce i UE

CBD (cannabidiol) is a legal substance in Poland and throughout the European Union. To understand this, one must distinguish CBD from THC (tetrahydrocannabinol). THC is a psychoactive substance, covered by the UN Convention on Psychotropic Substances and the Polish Act on Counteracting Drug Addiction — its possession and trade are strictly regulated. CBD, on the other hand, does not exhibit psychoactive or addictive effects.

Key legal event: in 2019, WHO (World Health Organization) issued a recommendation to remove CBD from Schedule IV of the UN Convention on Psychotropic Substances, confirming that CBD does not meet the criteria for a controlled substance. The UN Commission on Narcotic Drugs approved this recommendation in December 2020.

In Poland, CBD comes from industrial hemp (Cannabis sativa L.) with a THC content below 0.2% — which is legally permitted. CBD supplements from such hemp are legal for both sale and possession. The registration of Epidiolex by the EMA in 2019 completed this picture: the EU effectively recognized CBD as a substance with therapeutic use, which strengthened its legal status.

An important boundary: "CBD is legal" does not mean that all CBD products are identical or equivalent. Epidiolex is a pharmaceutical drug under the supervision of a neurologist. CBD supplements are consumer products — there are no regulations regarding clinical efficacy. When purchasing CBD oil as a supplement, you are not buying a drug for epilepsy. This understanding is fundamental for the safe use of CBD.

Interactions of CBD with antiepileptic drugs – what do we know from clinical studies

Clinical studies on Epidiolex have revealed important pharmacokinetic interactions that must be known to any neurologist treating a patient with CBD. Two interactions deserve special attention.

Walproinian sodu: CBD inhibits the enzymes CYP3A4 and UGT1A9, which metabolize valproic acid. In clinical studies of Epidiolex, a 25–50% increase in valproate concentration was observed with concurrent use of CBD. Elevated valproate increases the risk of hepatotoxicity (liver damage) — which was an observed adverse effect in studies, requiring monitoring of liver enzymes. In patients on valproate therapy combined with CBD, regular monitoring of ALT/AST is necessary.

Klobazam: CBD inhibits the CYP2C19 enzymes responsible for metabolizing clobazam to N-desmethylclobazam (norKLOB) — its active metabolite. The increase in norKLOB concentration may be responsible for part of the anticonvulsant effect observed when combining CBD with clobazam, but also for intensified adverse effects (excessive sedation). This interaction has been thoroughly analyzed in studies. Szaflarski i wsp. (2018).

Implications for practice: any combination of CBD (both Epidiolex and higher-dose CBD supplements) with antiepileptic drugs should occur under the supervision of a neurologist with standard monitoring of drug and liver enzyme levels. Self-administration of CBD supplements by individuals with epilepsy without consulting a neurologist is risky.

Inne formy padaczki – czy CBD ma zastosowanie poza Dravetem i Lennox-Gastaut?

The registration of Epidiolex pertains to Dravet and Lennox-Gastaut — but studies suggest potential applications of CBD in other forms of epilepsy. Tuberous sclerosis complex (TSC) is another indication: in 2020, the FDA approved Epidiolex for the treatment of seizures in TSC. Research is ongoing regarding CBD in epilepsy with SCN8A mutation, focal epilepsy, and other syndromes.

Outside of controlled studies: case series and observational studies suggest improvement with the use of CBD (both Epidiolex and full-spectrum preparations) in children with various forms of refractory epilepsy. Tzadok i wsp. (Seizure, 2016) They retrospectively described a series of 74 children with drug-resistant epilepsy treated with CBD — a reduction in seizure frequency was observed in 89%, with 18% experiencing a reduction exceeding 75%. These are strong observational data that require confirmation in RCT.

A perspective that is missing in the press: The debate about "CBD for epilepsy" is often flattened into a binary choice: "CBD supplement = epilepsy medication" vs "CBD is just a supplement, it doesn’t cure." The reality is more complex. There is a spectrum: from supplemental CBD oils with limited evidence, through full-spectrum extracts used by parents in "Charlotte’s Web" protocols (a historical case), to the pharmaceutical Epidiolex with a full set of clinical studies. Effects in epilepsy have been observed with very different CBD preparations, and it cannot be claimed that only Epidiolex works, nor that every CBD supplement can replace a neurologist. A neurologist and a pharmaceutical preparation are essential in epilepsy — but the history of CBD in this field began with parents who dared to try before science confirmed it.

Practical tips for parents of children with drug-resistant epilepsy

If your child has drug-resistant epilepsy and you've heard about CBD, a few specific steps can help navigate this complex situation.

The first step is to talk to the neurologist in charge — not from the internet, not from support groups, but with a doctor who knows your child's history. Some neurologists in Poland have experience with Epidiolex through targeted import and can explain whether it is indicated in a specific case. The neurologist can also assess what interactions are possible with your child's current medications.

Patient associations are a valuable resource: The Foundation I Have Epilepsy, the Epilepsy Fighting Association, and local support groups have experience with the targeted import procedure and can help navigate the system. Do not start with CBD supplements without the neurologist's consent — the risk of interactions with antiepileptic drugs is real and can be serious.

If the neurologist deems the targeted import of Epidiolex justified, the site gov.pl/web/zdrowie/import-docelowy contains current information about the administrative procedure. You can also check the details of accessing CBD in the legal context in Poland in the article CBD a prawo i testy narkotykowe.

Frequently Asked Questions

Does CBD treat epilepsy?

CBD w postaci leku Epidiolex jest zarejestrowanym lekiem przeciwpadaczkowym, zatwierdzonym przez FDA w 2018 roku i EMA w 2019 roku. Devinsky i wsp. (NEJM, 2017) showed a reduction in seizure frequency of 38.9% vs 13.3% placebo in Dravet syndrome. CBD supplements from stores are not medications and do not have the same therapeutic power.

What is Epidiolex and is it available in Poland?

Epidiolex is a medication containing purified CBD 100 mg/ml, approved by the EMA. In Poland, it is available through targeted import after the neurologist's decision and the consent of GIF/MZ. The cost of therapy ranges from several to several thousand zlotys per month. Organizational and financial assistance is available through patient associations.

Do CBD supplements help with epilepsy?

Supplemental CBD oils contain significantly lower doses than Epidiolex (10–20 mg/kg body weight/day). They do not have clinically documented efficacy in epilepsy. Using them without the neurologist's knowledge is risky due to possible interactions with antiepileptic drugs.

Dlaczego CBD jest legalne, skoro pochodzi z konopi?

CBD comes from industrial hemp with THC below 0.2% and is not a controlled substance. The WHO removed CBD from the list of psychoactive substances in 2019. The registration of Epidiolex by the EMA confirmed the status of CBD as a medicinal substance, not a narcotic.

What are the interactions of CBD with anticonvulsants?

CBD may increase the concentration of valproate (risk of hepatotoxicity) and the active metabolite of clobazam (risk of sedation). Any combination of CBD with antiepileptic drugs requires supervision by a neurologist and monitoring of drug and liver enzyme levels.

Can CBD cause seizures?

There is no data indicating that CBD triggers seizures in healthy individuals. In studies of Epidiolex, CBD reduced seizures. However, sudden withdrawal of CBD in a patient with epilepsy who has been using it regularly can — like any antiepileptic drug — lead to rebound phenomena. Always taper off gradually under the supervision of a neurologist.

This article is for informational and educational purposes only and does not constitute medical advice. Before starting to use cannabis or CBD for therapeutic purposes, consult with a physician, especially if you are taking other medications, are pregnant, or breastfeeding.

Author: Michał Waluk · Published: 2026-05-04 · Updated: 2026-05-04