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Epidiolex Side Effects

Generic Name: cannabidiol

Note: This document contains side effect information about cannabidiol. Some of the dosage forms listed on this page may not apply to the brand name Epidiolex.

For the Consumer

Applies to cannabidiol: oral solution

Side effects requiring immediate medical attention

Along with its needed effects, cannabidiol (the active ingredient contained in Epidiolex) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking cannabidiol:

More common

  • Agitation
  • chills
  • cough
  • fever
  • hoarseness
  • irritability
  • lower back or side pain
  • painful or difficult urination
  • unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness

Less common

  • Aggression
  • anger
  • blue lips, fingernails, or skin
  • confusion
  • diarrhea
  • difficult or troubled breathing
  • dizziness
  • fast heartbeat
  • irregular, fast or slow, or shallow breathing
  • loss of appetite
  • nausea
  • stomach pain

Side effects not requiring immediate medical attention

Some side effects of cannabidiol may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Decreased appetite
  • lack or loss of strength
  • rash
  • trouble sleeping

Less common

  • Change in walking and balance
  • clumsiness or unsteadiness
  • decreased weight
  • drooling
  • increased saliva

For Healthcare Professionals

Applies to cannabidiol: oral liquid


The more commonly reported adverse reactions have included somnolence, decreased appetite, diarrhea, transaminase elevations, rash, and insomnia[Ref]


In clinical trials, 13% of drug-treated patients experienced hepatic transaminase elevations of greater than 3 times the upper limit of normal (3 x ULN) compared to 1% in placebo patients. Less than 1% had elevations greater than 20 x ULN. Most ALT elevations occurred in patients concomitantly taking valproate and/or clobazam (30% taking both concomitant valproate and clobazam; 21% taking concomitant valproate; 4% concomitant clobazam). Just 3% of transaminase elevations occurred in patients taking neither valproate or clobazam.

Transaminase elevations were dose related. ALT elevations greater than 3 x ULN occurred in 17% of patients taking 20 mg/kg/day compared to 1% in patients taking 10 mg/kg/day.

Patients with baseline transaminase elevations above the ULN had higher rates of treatment emergent ALT elevations. For patients taking 20 mg/kg/day, ALT elevations to greater than 3 x ULN occurred in 30% of patients who had baseline ALT elevations compared to 12% in patients whose ALT levels were within the normal range at baseline.

Very common (10% or more): Elevated hepatic transaminases (up to 16%)


Common (1% to 10%): Insomnia, sleep disorder, poor quality sleep, irritability, agitation, aggression, anger[Ref]

Nervous system

Somnolence and sedation (including lethargy) occurred in 32% of patients compared with 11% of those on placebo. Occurrences were higher among patients on higher doses (34% vs 27% for doses of 20 mg/kg/day and 10 mg/kg/day, respectively). Occurrences were even higher in patients on concomitant clobazam (46% vs 16%).[Ref]

Very common (10% or more): Somnolence (up to 25%)

Common (1% to 10%): Sedation, lethargy, gait disturbance[Ref]


Frequency not reported: Hypersensitivity reaction (pruritus, erythema, angioedema)[Ref]


Common (1% to 10%): Decreased weight[Ref]


Very common (10% or more): Laboratory-defined anemia (30%)[Ref]

Mean decreases in hemoglobin (-0.42 g/dL) and hematocrit of (-1.5%) occurred in patients receiving this drug. Thirty percent of patients developed a new laboratory-defined anemia during the clinical trial defined as a normal hemoglobin at baseline and a reported value less than the lower limit of normal at a subsequent time. This is compared to 13% percent of placebo patients.[Ref]


Very common (10% or more): Viral infection (up to 11%), other infection (up to 21%)

Common (1% to 10%): Fungal infection[Ref]


Common (1% to 10%): Pneumonia, hypoxia, respiratory failure[Ref]


Very common (10% or more): Fatigue, malaise, and asthenia (up to 12%)[Ref]


Frequency not reported: Increases in creatinine[Ref]

This drug increased serum creatinine in healthy adults and in patients with Lennox-Gastaut syndrome or Dravet Syndrome. An increase of about 10% has been observed within 2 weeks of initiating therapy. In healthy adults, this increase was reversible. Reversibility was not assessed in patients with Lennox-Gastaut syndrome or Dravet Syndrome. The mechanism for this increase is unknown.[Ref]


Very common (10% or more): Rash (up to 13%)[Ref]


Very common (10% or more): Decreased appetite (up to 22%), diarrhea (up to 20%)

Common (1% to 10%): Drooling, salivary hypersecretion, gastroenteritis, abdominal pain[Ref]


1. "Product Information. Epidiolex (cannabidiol)." Greenwich Biosciences Inc, Carlsbad, CA.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

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