Antiepileptic drug agent | Bioavailability (PO formulation) | Protein binding | Half-life | Metabolism | Elimination |
---|---|---|---|---|---|
Brivaracetam | Almost completely absorbed | ≤ 20% | ~  9 h | Hydrolysis (primary route) CYP2C19 | ≥ 95% renally |
Carbamazepine | 75–85% Total daily intravenous dose should be equivalent to 70% of previous total daily oral dose | 75–95% | Range: 30–60 h After autoinduction: 12–17 h | > 90% by CYP3A4 | 72% renally |
Clobazam | 87% | 80–90% | 36 to 42 h | Hepatic via CYP3A4 and to a lesser extent via CYP2C19 | 82% renally |
Clonazapam | ~ 90% | ~ 85% | 17–60 h | Glucuronide and sulfate conjugation | < 2% renally as unchanged drug |
Diazepam | > 90% | 98% | Parent drug: ~ 60 to 72 h; metabolite ~ 152 to 174 h | CYP3A4 and 2C19 | Renally |
Eslicarbazepine | > 90% | < 40% | 13–20 h | Hydrolytic first-pass metabolism | 90% renally |
Fosphenytoin | 100% (intramuscular formulation) | 95–99% | 12–28.9 h | CYP2C9 CYP2C19 | Renally |
Lacosamide | 100% | < 15% | 13 h | CYP3A4, CYP2C9, CYP2C19 | 95% renally |
Lamotrigine | 98% | 55% | 25–70 h | Conjugation | 94% renally |
Levetiracetam | 100% | < 10% | 6–8 h | Hydrolysis | 66% renally |
Lorazepam | 90% | ~ 91% | 12–18 h | Conjugation | 88% renally |
Midazolam | Â | Â | Â | Â | Â |
Oxcarbazepine | Readily absorbed | 40% | Active metabolite: 9–11 h | Glucoronidation | 95% renally |
Pentobarbital | – | 45% to 70% | 15–50 h | Hydroxylation and glucuronidation | < 1% renally as unchanged drug |
Perampanel | Completely and rapidly absorbed | 95% | ~ 105 h | CYP 3A4/5 primary; lesser extent CYP 1A2/2B6 | 22% renally |
Phenytoin | 20–90% | 90–95% | 7–42 h | CYP2C9, 2C19 (major) and 3A4 (minor) | < 5% renally as unchanged drug |
Phenobarbital | ~ 95–100% | 50% | Longest half-life 46–136 h | CYP450 and UGT mediated | 25–50% renally |
Topiramate | 80% | 15–41% | IR: 21 h ER: 31–56 h | No extensive metabolism | 70% renally |
Valproic acid | 90% | 80–90% | 9–16 h | CYPs 2C9, 2C19, 2A6, UGT-glucuronidation | 70–80% renally |
Zonisamide | Rapid and complete absorption | 40% | 50–68 h | CYP 3A4 | 60% renally |