ObjectiveTo evaluate the safety and preliminary pharmacokinetics of a pharmaceutical formulation of purified cannabidiol (CBD) in children with Dravet syndrome.MethodsPatients aged 4–10 years were randomized 4:1 to CBD (5, 10, or 20 mg/kg/d) or placebo taken twice daily. The double-blind trial comprised 4-week baseline, 3-week treatment (including titration), 10-day taper, and 4-week follow-up periods. Completers could continue in an open-label extension. Multiple pharmacokinetic blood samples were taken on the first day of dosing and at end of treatment for measurement of CBD, its metabolites 6-OH-CBD, 7-OH-CBD, and 7-COOH-CBD, and antiepileptic drugs (AEDs; clobazam and metabolite N-desmethylclobazam [N-CLB], valproate, levetiracetam, topiramate, and stiripentol). Safety assessments were clinical laboratory tests, physical examinations, vital signs, ECGs, adverse events (AEs), seizure frequency, and suicidality.ResultsThirty-four patients were randomized (10, 8, and 9 to the 5, 10, and 20 mg/kg/d CBD groups, and 7 to placebo); 32 (94%) completed treatment. Exposure to CBD and its metabolites was dose-proportional (AUC0–t). CBD did not affect concomitant AED levels, apart from an increase in N-CLB (except in patients taking stiripentol). The most common AEs on CBD were pyrexia, somnolence, decreased appetite, sedation, vomiting, ataxia, and abnormal behavior. Six patients taking CBD and valproate developed elevated transaminases; none met criteria for drug-induced liver injury and all recovered. No other clinically relevant safety signals were observed.ConclusionsExposure to CBD and its metabolites increased proportionally with dose. An interaction with N-CLB was observed, likely related to CBD inhibition of cytochrome P450 subtype 2C19. CBD resulted in more AEs than placebo but was generally well-tolerated.Classification of evidenceThis study provides Class I evidence that for children with Dravet syndrome, CBD resulted in more AEs than placebo but was generally well-tolerated.

BackgroundA formal single ascending and multiple dose pharmacokinetic (PK) trial of cannabidiol (CBD) oral solution was required to determine the safety and tolerability of CBD, the maximum tolerated dose, and to examine the effect of food on CBD PK parameters.ObjectiveThis trial assessed the safety, tolerability and PK of CBD oral solution in healthy adult volunteers, as well as the effect of food on CBD PK parameters.MethodsThe study consisted of three arms: single ascending dose (1500, 3000, 4500 or 6000 mg CBD [n = 6 per group]/placebo [n = 8; 2 per CBD dose group]), multiple dose (750 or 1500 mg CBD [n = 9 per group]/placebo [n = 6; 3 per CBD dose group] twice daily), and food effect (1500 mg CBD single dose [n = 12]). All subjects completed all trial arms and were analyzed as planned.ResultsCBD was generally well tolerated. Diarrhea, nausea, headache, and somnolence were the most common adverse events (AEs) across all trial arms, with an increased incidence of some gastrointestinal and nervous system disorder AEs (most notably diarrhea and headache) apparent in subjects taking CBD compared with placebo. All AEs were of mild or moderate severity; none were severe or serious. There were no deaths or discontinuations in the trial. After single oral doses, CBD appeared rapidly in plasma; time to maximum plasma concentration (tmax) was approximately 4–5 h. The major circulating metabolite was 7-carboxy-CBD, then parent CBD, 7-hydroxy-CBD (active metabolite), and 6-hydroxy-CBD (a relatively minor metabolite). Plasma exposure to CBD [maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from time zero to time t (AUCt)] increased in a less than dose-proportional manner (Cmax slope 0.73; AUCt slope 0.64). Oral clearance of CBD was high (1111–1909 L/h) and apparent volume of distribution was large (20,963–42,849 L). CBD reached steady state after approximately 2 days, with moderate accumulation (1.8- to 2.6-fold) after 750 and 1500 mg CBD twice daily. After 7 days, a twofold increase in CBD dose resulted in 1.6- and 1.9-fold increases in geometric mean Cmax and area under the plasma concentration-time curve over a dosing interval (AUCτ), respectively. CBD elimination was multiphasic; the terminal elimination half-life was approximately 60 h after 750 and 1500 mg CBD twice daily; and effective half-life estimates ranged from 10 to 17 h. Cmax was 541.2 ng/mL and AUCτ was 3236 ng·h/mL after 1500 mg CBD twice daily. A high-fat meal increased CBD plasma exposure (Cmax and AUCt) by 4.85- and 4.2-fold, respectively; there was no effect of food on tmax or terminal half-life.ConclusionCBD was generally well tolerated. Most AEs were mild in severity; none were severe or serious. The safety and PK profile support twice-daily administration of CBD.

GW Pharmaceuticals’ formulation of highly purified cannabidiol oral solution is approved in the United States for seizures associated with Lennox‐Gastaut and Dravet syndromes in patients aged ≥2 years, for which clobazam, stiripentol, and valproate are commonly used antiepileptic drugs. This open‐label, fixed‐sequence, drug‐drug interaction, healthy volunteer trial investigated the impact of cannabidiol on steady‐state pharmacokinetics of clobazam (and N‐desmethylclobazam), stiripentol, and valproate; the reciprocal effect of clobazam, stiripentol, and valproate on cannabidiol and its major metabolites (7‐hydroxy‐cannabidiol [7‐OH‐CBD] and 7‐carboxy‐cannabidiol [7‐COOH‐CBD]); and cannabidiol safety and tolerability when coadministered with each antiepileptic drug. Concomitant cannabidiol had little effect on clobazam exposure (maximum concentration [Cmax] and area under the concentration‐time curve [AUC], 1.2‐fold), N‐desmethylclobazam exposure increased (Cmax and AUC, 3.4‐fold), stiripentol exposure increased slightly (Cmax, 1.3‐fold; AUC, 1.6‐fold), while no clinically relevant effect on valproate exposure was observed. Concomitant clobazam with cannabidiol increased 7‐OH‐CBD exposure (Cmax, 1.7‐fold; AUC, 1.5‐fold), without notable 7‐COOH‐CBD or cannabidiol increases. Stiripentol decreased 7‐OH‐CBD exposure by 29% and 7‐COOH‐CBD exposure by 13%. There was no effect of valproate on cannabidiol or its metabolites. Cannabidiol was moderately well tolerated, with similar incidences of adverse events reported when coadministered with clobazam, stiripentol, or valproate. There were no deaths, serious adverse events, pregnancies, or other clinically significant safety findings.

The pharmacokinetics and safety of a single oral dose of 200‐mg plant‐derived pharmaceutical formulation of highly purified cannabidiol (CBD) in oral solution (Epidiolex in the United States; 100 mg/mL) were assessed in subjects with mild to severe hepatic impairment (n =  8 each for mild and moderate, n = 6 for severe) relative to matched subjects with normal hepatic function (n = 8). Blood samples were collected until 48 hours after dosing and evaluated by liquid chromatography and tandem mass spectrometry. Pharmacokinetic parameters (primarily maximum measured plasma concentration, area under the plasma concentration–time curve from time zero to time t, area under the concentration‐time curve from time zero to infinity, time to maximum plasma concentration, and terminal half‐life) of CBD and its major metabolites were derived using non‐compartmental analysis. CBD was rapidly absorbed in all groups independent of hepatic function (median time to maximum plasma concentration, 2‐2.8 hours). Exposure (area under the concentration–time curve from time zero to infinity) to total CBD slightly increased in subjects with mild hepatic impairment (geometric mean ratio [GMR], 1.48; 90% confidence interval [CI], 0.90‐2.41). However, there were clinically relevant increases in subjects with moderate (GMR, 2.45; 90%CI, 1.50‐4.01) and severe (GMR, 5.15; 90%CI, 2.94‐9.00) hepatic impairment, relative to subjects with normal hepatic function. Exposure to the CBD metabolites (6‐hydroxy‐CBD and 7‐hydroxy‐CBD) also increased in subjects with moderate and severe hepatic impairment, but to a lesser extent than the parent drug. The 7‐carboxy‐CBD metabolite exposure was lower in subjects with severe hepatic impairment when compared with subjects with normal liver function. These findings indicate that dose modification is necessary in patients with moderate and severe hepatic impairment, and a lower starting dose and slower titration are necessary based on benefit‐risk. CBD was well tolerated, and there were no serious adverse events reported during the trial.

Objective The pharmacokinetics (PK) and safety of single oral 750‐mg doses of a plant‐derived pharmaceutical formulation of highly purified cannabidiol (CBD; Epidiolex in the USA and Epidyolex in Europe; 100‐mg/mL oral solution) were assessed in healthy adults following a high‐fat/calorie meal (n = 15), a low‐fat/calorie meal (n = 14), whole milk (n = 15), or alcohol (n = 14), relative to the fasted state (n = 29). Methods Blood samples were collected until 96 hours postdose in each period and evaluated by liquid chromatography and tandem mass spectrometry. PK parameters (maximum observed plasma concentration [Cmax], area under the plasma concentration‐time curve from time zero to the last observed quantifiable concentration, area under the concentration‐time curve from time zero to infinity [AUC0‐∞], and time to maximum plasma concentration [tmax]) of CBD and its major metabolites were derived using noncompartmental analysis. Results CBD exposure increased by 3.8‐fold for AUC0‐∞ and 5.2‐fold for Cmax when CBD was administered with a high‐fat/calorie meal versus fasted. To a lesser extent, a low‐fat/calorie meal enhanced CBD exposure versus fasted with a 2.7‐fold increase in AUC0‐∞ and a 3.8‐fold increase in Cmax. Similarly, when dosed with whole milk, CBD exposure increased versus fasted by 2.4‐fold for AUC0‐∞ and 3.1‐fold for Cmax. Modest elevations in CBD exposure occurred when it was dosed with alcohol: 1.6‐fold for AUC0‐∞ and 1.9‐fold for Cmax. No clinically relevant effect of any test condition on CBD tmax or t½ versus the fasted state was apparent. The same trend was seen for the CBD metabolites, except that 7‐carboxy‐cannabidiol tmax was considerably longer when CBD was administered with alcohol (14 vs 4 hours fasted). Inter‐ and intrasubject variability in PK parameters was moderate to high during the trial. Significance CBD and metabolite exposures were most affected by a high‐fat/calorie meal. CBD exposures also increased with a low‐fat/calorie meal, whole milk, or alcohol, but to a lesser extent. CBD was tolerated, and there were no severe or serious adverse events during the trial.