. 2010 Aug 20;3(8):2709–2732. doi: 10.3390/ph3082709

Table 1.

Pharmacokinetic characteristics of antiepileptic drugs.

AED	Oral bioavailability	t_1/2 (hour)	Clearance	Active metabolites	Enzymes involved in the metabolism of the compound
Carbamazepine	75–85%	12–24	>95% Hepatic	Carbamazepine-10,11-epoxide	CYP3A4/5, CYP2C8, mEH, UGTs
Clobazam	87%	22–30	>95% Hepatic	N-desmethylclobazam	CYP3A4 and CYP2C19
Clonazepam	>80%	19–60	>95% Hepatic	—	CYP3A4
Ethosuximide	<100%	36–60	65% Hepatic	—	CYP3A4
Ethosuximide	<100%	36–60	35% Renal	—	CYP3A4
Felbamate	90%	14–23	50% Hepatic	—	CYP2C19?, UGTs
Felbamate	90%	14–23	50% Renal	—	CYP2C19?, UGTs
Gabapentin	45–70%	5–7	100% Renal	—	None
Lamotrigine	<100%	24–36	90% Hepatic	—	UGTs
Lamotrigine	<100%	24–36	10% Renal	—	UGTs
Levetiracetam	<100%	6–8	66% Renal	—	Nonhepatic hydrolysis (in blood)
Levetiracetam	<100%	6–8	34% Hepatic	—	Nonhepatic hydrolysis (in blood)
Oxcarbazepine	> 95%	1–2	45% Hepatic	MHD	UGTs
Oxcarbazepine	> 95%	1–2	65% Renal	MHD	UGTs
Phenobarbital	80–100%	72–96	75% Hepatic	—	CYP2C19, CYP2C9
Phenobarbital	80–100%	72–96	25% Renal	—	CYP2C19, CYP2C9
Phenytoin	95%	20–50	>90% Hepatic	—	CYP2C9, CYP2C19
Primidone	<100%	10–20	50% Hepatic	Phenobarbital	CYP2C9 (for phenobarbital)
Primidone	<100%	10–20	50% Renal	Phenylethylmalonamide	CYP2C9 (for phenobarbital)
Topiramate	80%	20–30	30–50% Hepatic	—	CYP3A4, UGTs
Topiramate	80%	20–30	50–70% Renal	—	CYP3A4, UGTs
Valproic acid	<100%	8–16	>95% Hepatic	—	UGTs, CYP2C9, CYP2C19
Zonisamide	<100%	50–70	>90% Hepatic	—	CYP3A4, CYP2C19, UGTs

This table is prepared based on the previous review articles [7,22,25,26] with modifications. AED, antiepileptic drug; t_1/2, elimination half-life; CYP, cytochrome P450; mEH, microsomal epoxide hydrolase; UGTs, UDP-glucuronosyltransferases; MHD, monohydroxylated active metabolite of oxycarbazepin.