The present invention relates to the use of cannabidiol (CBD) in combination with an agonist of 5-HT2B receptors. Such a combination provides protection against the adverse effects caused by agonists of 5-HT2B receptors. The invention further relates to the use of CBD in combination5 with an amphetamine or amphetamine derivative in the treatment of epilepsy. In one embodiment the CBD is used in combination with the amphetamine derivative fenfluramine to produce a significant reduction in seizures. Preferably the CBD used is in the form of a highly purified extract of cannabis such that the CBD is present at greater than 98% of the total extract (w/w) and the other components of the extract are characterised. In particular the cannabinoid10 tetrahydrocannabinol (THC) has been substantially removed, to a level of not more than 0.15% (w/w) and the propyl analogue of CBD, cannabidivarin, (CBDV) is present in amounts of up to 1%. Alternatively, the CBD may be a synthetically produced CBD. In use the CBD in combination with an agonist of 5-HT2B receptors, amphetamine or amphetamine derivative may be formulated for administration separately, sequentially or simultaneously with the15 amphetamine or amphetamine derivative or the combination may be provided in a single dosage form. Where the CBD is formulated for administration separately, sequentially or simultaneously it may be provided as a kit or together with instructions to administer the one or more components in the manner indicated.
