Cannabidiol beneficial for long-term use in patients with refractory epilepsy

Cannabidiol (CBD) helps control seizures in patients with refractory epilepsy, with the effect lasting for up to 5 years of treatment, a study has found.

The retrospective study used data from the Massachusetts General Hospital's open-label expanded access programme for CBD as a new treatment for epilepsy. A total of 54 patients used CBD for up to 60 months (median 45.5 months).

CBD led to a reduction in the frequency of seizures, and this benefit persisted from the first year of treatment to the most recent study visit. Throughout the follow-up period, the number of seizure responders remained similar (41.7–42.6 percent), as was the seizure response rate (p=0.12).

Efficacy was also observed across a broad range of dose, up to 50 mg/kg/day. The seizure-control benefit of CBD was more prominent in the setting of tuberous sclerosis complex and in patients with epileptic spasms and absence seizures.

CBD, while falling short of reducing requirement for concomitant antiepileptic drug (AED) use, led to most patients lowering their AED use to at least one relative to baseline.

In terms of safety, CBD was generally well tolerated. The most common adverse reactions were drowsiness and diarrhoea.

Overall, the present data show that CBD is effective and safe for use in the long-term treatment of refractory epilepsies.