Cannabidiol (Epidyolex): Epilepsy Uses, Safety and Interactions

Which cannabidiol product is covered?

This summary concerns prescription Epidyolex 100 mg/ml oral solution under its UK label. Its concentration and supplied measuring device matter; it is not a general treatment for anxiety, insomnia or pain.

Approved epilepsy use and monitoring

The UK label covers additional treatment for Lennox-Gastaut or Dravet seizures with clobazam from age two, and tuberous-sclerosis-complex seizures from age two. Treatment needs specialist supervision. Food changes exposure, so the relationship to meals should be consistent.

Sleepiness, diarrhoea and reduced appetite are common. Liver injury is an important risk: liver blood tests are needed before and during treatment. New yellowing of the skin or eyes, dark urine or persistent vomiting warrants prompt assessment.

Interactions and reproductive safety

Clobazam can increase sedation, while valproate increases the likelihood of raised liver enzymes. Rifampicin and other strong enzyme inducers can lower cannabidiol exposure. Alcohol and sedating medicines can add impairment. These combinations need a medicine-list review, not a self-directed dose change.

The UK label advises pregnancy use only when maternal benefit clearly outweighs fetal risk, and discontinuation of breastfeeding during treatment. Discuss either situation with the treating team.

Why retail CBD is not an equivalent

The FDA distinguishes its approved prescription cannabidiol medicine from other CBD products marketed with unproven treatment claims. Approval of one pharmaceutical product does not establish that a different oil, supplement or internet product has the same quality, concentration or clinical effect. CBD is a single compound; cannabis contains many compounds, including THC, which causes the characteristic high. A description such as hemp or CBD alone does not establish the composition of a finished product.

FDA consumer information also warns that liver damage and medicine interactions can occur without an obvious early warning. Mixing CBD with alcohol or medicines that slow brain activity can increase sedation and injuries. A product described as natural therefore still belongs on the medicine list. Keep the actual packaging available so a clinician or pharmacist can identify what was taken.

Sources and scope

• Epidyolex 100 mg/ml oral solution: UK SmPC — Jazz Pharmaceuticals; text revised 8 June 2026
• FDA consumer update: CBD product safety — FDA consumer information; consulted 30 October 2026

Sources checked: 30 October 2026. This records a source check, not a clinical review by a doctor or pharmacist. The current leaflet for the actual product and professional assessment guide personal treatment.