Study register · detailMeta-Analyse · Epilepsy · 2014
Cannabinoids for epilepsy
Gloss et al.·Cochrane Database of Systematic ReviewsImpact 6.6
UnclearGRADEModerate229 citations
Samplek = 4 Studien n = 48 Pat.
Durationunclear
ControlPlacebo or control group
EndpointSeizure freedom
Blindingunklar
DesignMeta-Analyse
Cannabinoidcbd
Max. dose300.0 mg
Routeoral
”Key finding
No reliable conclusions on the efficacy of cannabinoids in epilepsy possible; only safety data available.
Summary
Cochrane SR (2014 update) of k=4 RCTs (n=48), all with cannabidiol as add-on therapy; antiepileptic drugs were continued. All studies of low quality without sufficient randomisation details. Primary endpoint (seizure freedom ≥1 year) not reported. Secondary endpoint adverse effects: no adverse events documented in the treatment groups. No reliable conclusions on the efficacy of cannabinoids in epilepsy possible.
P
PopulationPersons with epilepsy (mono- or add-on therapy), pooled n=48
I
InterventionCannabidiol (CBD) 200–300 mg/day orally, as mono- or add-on therapy
C
ControlPlacebo or control group (details unclear)
O
OutcomeNo reliable conclusions on efficacy possible; no adverse effects reported in the treatment groups
Confidence in the evidence
Very lowLowModerateHigh
Moderate
The third of four GRADE levels, the effect estimate is probably reliable.
Background: Cannabis appears to have anti-epileptic effects in animals. It is not currently known if it is effective in patients with epilepsy. Some states in the United States of America have explicitly approved its use for epilepsy.
Objectives: To assess the efficacy and safety of cannabinoids when used as monotherapy or add-on treatment for people with epilepsy.
Search Methods: We searched the Cochrane Epilepsy Group Specialized Register (9 September 2013), Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 8), MEDLINE (Ovid) (9 September 2013), ISI Web of Knowledge (9 September 2013), CINAHL (EBSCOhost) (9 September 2013), and ClinicalTrials.gov (9 September 2013). In addition, we included studies we personally knew about that were not found by the searches, as well as searched the references in the identified studies.
Selection Criteria: Randomized controlled trials (RCTs) whether blinded or not.
Data Collection And Analysis: Two authors independently selected trials for inclusion and extracted the data. The primary outcome investigated was seizure freedom at one year or more, or three times the longest interseizure interval. Secondary outcomes included responder rate at six months or more, objective quality of life data, and adverse events.
Main Results: We found four randomized trial reports that included a total of 48 patients, each of which used cannabidiol as the treatment agent. One report was an abstract and another was a letter to the editor. Anti-epileptic drugs were continued in all studies. Details of randomisation were not included in any study report. There was no investigation of whether the control and treatment participant groups were the same or different. All the reports were low quality.The four reports only answered the secondary outcome about adverse effects. None of the patients in the treatment groups suffered adverse effects.
Authors' Conclusions: No reliable conclusions can be drawn at present regarding the efficacy of cannabinoids as a treatment for epilepsy. The dose of 200 to 300 mg daily of cannabidiol was safely administered to small numbers of patients generally for short periods of time, and so the safety of long term cannabidiol treatment cannot be reliably assessed.