Epidyolex is generally well tolerated1



Overall population



The full adverse event profile, as reported in the Epidyolex Summary of Product Characteristics (SmPC), is presented below*. 


System Organ Class Frequency Adverse reactions from clinical trials
Infections and infestations Common Pneumonia, Bronchitis, Nasopharyngitis, Urinary tract infection
Metabolism and nutrition disorders

Very common Decreased appetite


Increased appetite
Psychiatric disorders Common Irritability, Insomnia, Aggression, Abnormal behaviour, Agitation
Nervous system disorders

Very common Somnolence


Lethargy, Drooling, Tremor
Respiratory, thoracic and mediastinal disorders Common Cough
Gastrointestinal disorders Very common Diarrhoea, Vomiting
Hepatobiliary disorders Common AST increased, ALT increased, GGT increased, Liver function test abnormal
Skin and subcutaneous tissue disorders Common Rash
General disorders and administration site conditions Very common Pyrexia, Fatigue
Investigations Common Weight decreased

*The frequencies are defined as follows: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100).


†Grouped Terms: Pneumonia: Pneumonia, Pneumonia RSV, Pneumonia mycoplasmal, Pneumonia adenoviral, Pneumonia viral, Aspiration pneumonia; Somnolence: Somnolence, Sedation.


Overall population is presented in-line with data provided in the SmPC. Epidyolex should only be prescribed as per the licensed indication.


At the request of the regulatory agency and in line with the licensed indication, a subgroup analysis has also ben carried out to assess tolerability in patients taking Epidyolex and clobazam concomitantly.

Heptocellular injury

Epidyolex is contraindicated in patients with transaminase elevations >3 times the ULN and bilirubin > 2 times the ULN1


Epidyolex can cause dose-related elevations of liver transaminases. Elevations typically occur in the first two months of treatment initiation. However, there were cases observed up to 18 months after initiation of treatment, particularly in patients taking concomitant valproate.


Resolution of transaminase elevations occurred with the discontinuation of Epidyolex or reduction Epidyolex and/or concomitant valproate in about two-thirds of the cases. In about one-third of the cases, transaminase elevations resolved during continued treatment with Epidyolex, without dose reduction.


Epidyolex should be discontinued with patients with sustained transaminase elevations of greater than 5 times the ULN. Dose adjustments of any co-administered medicinal product that is known to affect the liver should also be considered.

Risk factors

Concomitant valproate
Concomitant clobazam
Dose of Epidyolex
Baseline transaminase elevations

ULN, upper limit of normal

Sign up and stay up to date

Receive promotional communications and notifications about open-label extension data, our latest conference activity, key opinions from leading researchers and prescribers in cannabinoid therapy.



1. Epidyolex SmPC (Date accessed: April 2021).


2. GW Pharmaceuticals. Data on File: VV-MED-06864 (v1). 2019.