Table 4.

Commonly Used Anti-seizure Medications (ASMs), Their Primary Mechanisms of Action, Their Typically Prescribed Dosage Range in Milligrams (mg) Per Day, Indications for Drug Level Monitoring and Common Adverse Effects Associated with These Medications

Anti-seizure medications
ASM	Primary mechanism of action	Typical dosage in adults (in mg per day)	Drug level monitoring	Adverse effects
Levetiracetam	Binding to synaptic vesicle Protein 249	1000–300040	No current indication	Asthenia (15%), somnolence (15%), headache (14%)50
Valproate	GABA-receptor agonist Sodium-channel blocker41	500–250041	Initial therapeutic level Instances of suspected toxicity41	Nausea (48%), headache (31%), somnolence (27%), dizziness (25%), flu syndrome (12%), alopecia (6%)51
Phenobarbital	GABA-receptor agonist41	30–18041	Serum peak levels 2–8 h after initial intake and with dose increase41	Sedation (74%), dizziness (60%), memory difficulty (46%)52
Carbamazepine	Sodium-channel blocker41	400–160041	At short intervals (such as every 3 weeks) following initiation and can gradually increase to longer intervals (such as every 3 months) Soon after beginning a medication that interacts with cytochrome P45042	Drowsiness (36%), nausea (32%), weight gain (8%), tremor (8%), rash (4%)53
Phenytoin	Sodium-channel blocker41	150–40041	Initial therapeutic level (24 h after last oral dose)41	Hypotension (1–10%), nausea (13%), bruising (1–10%), nystagmus (59%), dizziness (31%)54
Lacosamide	Slow sodium-channel blocker 55	200–40055	No current indication	Dizziness (23%), somnolence (17%), headache (14%), nausea (10%)56
Lamotrigine	Sodium-channel blocker41	200–60044	No current indication	Headache (29%), nausea (19%), dizziness (38%), diplopia (28%), rash (10%)57
Topiramate	Sodium-channel blocker GABA-receptor agonist41	100–50045	Concurrent use of another medication that interacts with cytochrome P45045	Fatigue (15%), dizziness (25%), ataxia (16%), nausea (10%), somnolence (29%)58