Study register · detailMeta-Analyse · Epilepsy · 2012
Cannabinoids for epilepsy.
Gloss et al.·The Cochrane database of systematic reviewsImpact 6.6
UnclearGRADEModerate41 citations
Samplek = 4 Studien n = 48 Pat.
Durationgenerally short periods of time
ControlControl 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 adverse event data available (no adverse events reported in treatment groups).
Summary
Cochrane SR of k=4 RCTs (n=48 patients), all with cannabidiol as add-on to existing antiepileptic drugs; all studies of low quality without detailed information on randomisation. Primary endpoint (seizure freedom after ≥1 year) was not reported. Secondary endpoint adverse events: no adverse events in the treatment groups. No reliable conclusions on efficacy possible.
P
PopulationPatients with epilepsy, pooled n=48
I
InterventionCannabidiol (200–300 mg/day, oral), cannabinoids in general
C
ControlControl group (details unclear, no adequate description of randomisation)
O
OutcomeNo evaluable data on the primary endpoint (seizure freedom); only adverse event data: no adverse events in 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 of Cannabis, or one of Cannabis's constituents in the treatment of people with epilepsy.
Search Methods: We searched the Cochrane Epilepsy Group Specialized Register (May 15, 2012), the Cochrane Central Register of Controlled Trials (CENTRAL issue 4 of 12, The Cochrane Library 2012),MEDLINE (PubMed, searched on May 15, 2012), ISI Web of Knowledge (May 15, 2012), CINAHL (EBSCOhost, May 15, 2012), and ClinicalTrials.gov (May 15, 2012). In addition, we included studies we personally knew about that were not found by the searches, as well as 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 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 reports which 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. Details of randomisation were not included in any study. There was no investigation of whether control and treatment 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, for generally short periods of time, and so the safety of long term cannabidiol treatment cannot be reliably assessed.