Table 2 Summary of the pharmacological and clinical profile of antiseizure medications (ASMs) introduced in the market after 2015
From: The pharmacological treatment of epilepsy: recent advances and future perspectives
| Â | Brivaracetam | Cannabidiol | Cenobamate | Everolimus | Fenfluramine |
|---|---|---|---|---|---|
Chemical structure | Levetiracetam derivative | Cannabinoid | Carbamate derivative | Rapamycin derivative | Amphetamine derivative |
Approved epilepsy indications (United States) | Treatment of focal seizures in patients aged 1 month and older | Treatment of seizures associated with LGS, DS or TSC in patients 1 year of age and older | Treatment of focal seizures in adults | Add-on treatment of focal seizures associated with TSC in patients aged 2 years and older | Treatment of seizures associated with DS in patients 2 years of age and older. |
Main mechanisms of action | SV2A modulator | Several, including GPR55 antagonism, desensitization of TRPV1channels, enhanced adenosine-mediated signaling, and GABAergic effects. | Blockade of persistent sodium currents and increase of phasic and tonic GABA inhibition. | mTOR inhibition | Several, including indirect stimulation of 5-HT2C and 5-HT1D receptors as well as interactions with σ1-receptors |
Oral bioavailability | Complete (100%) | About 6% in the fasting state. About 25% when taken with a high-fat meal | About 90% | Variable | About 80% |
Main route of elimination | CYP2C19-mediated hydroxylation and hydrolysis | CYP2C19 and CYP3A4-mediated oxidation, and other metabolic pathways | UGT2B7- and UGT2B4-mediated glucuronidation and CYP-mediated oxidation | CYP3A4-mediated metabolism | CYP-mediated metabolism, involving conversion to the active metabolite norfenfluramine |
Half-life | About 9 h | About 15 h after a single dose, and about 60 h after multiple dosing | About 50–60 h | About 30 h | Fenfluramine = about 20 h. Norfenfluramine = about 24 to 48 h |
Most common adverse effects | Sommnolence, fatigue, dizziness, coordination disturbances, mood and behavioural disturbances | Somnolence, anorexia, diarrhea, fatigue, sleep disorders, behavioral disturbances | Dizziness, fatigue, somnolence, ataxia, dysarthria, visual disturbances, gastrointestinal disturbances | Stomatitis, pyrexia, pneumonia, diarrhea, hypercholesterolemia | Anorexia, decreased weight, diarrhea, constipation, somnolence, fatigue, coordination disturbances, behavioral disturbances |
Other adverse effects of potential concern | Hypersensitivity reactions | Hypersensitivity reactions, increased liver enzymes, pneumonia | Hypersensitivity reactions | Hypersensitivity reactions, infections, renal failure, myelosuppression | Cardiac valvulopathy, pulmonary hypertension, serotonin syndrome |
Main drug interactions | Serum brivaracetam levels can be increased by cannabidiol, and moderately reduced by enzyme inducing ASMs. Brivaracetam increases serum levels of carbama-zepine-10,11-epoxide | Cannabidiol inhibits the metabolism of several drugs. In particular, it increases markedly the serum levels of norclobazam, the active metabolite of clobazam | Serum cenobamate levels are decreased by phenytoin. Cenobamate increases serum phenytoin levels, and can modify the serum levels of several other drugs | Serum everolimus levels can be increased by inhibitors of P-gp and by CYP3A4 inhibitors, and decreased by inducers of P-gp / CYP3A4 | Serum fenfluramine levels are increased by the combination of stiripentol with clobazam. Use together with other serotoninergic drugs may involve a risk of precipitating a serotonin syndrome |