Specific Antiseizure Medications

Medication Name	Indications	Adverse Effects
	Refractory absence seizures	Renal calculi, dehydration, metabolic acidosis
	Adjunctive therapy for seizures in Lennox-Gastaut syndrome and Dravet syndrome in patients ≥ 2 years	Somnolence, hepatocellular injury with elevated aminotransferases, anorexia, fatigue, insomnia, diarrhea
	Focal-onset, generalized-onset tonic-clonic, and mixed seizures (but not absence, myoclonic, or atonic seizures)	Diplopia, dizziness, nystagmus, gastrointestinal (GI) upset, dysarthria, lethargy, low white blood cell (WBC) count (3000 to 4000/mcL), hyponatremia, severe rash, including Stevens-Johnson syndrome (in 5%) Idiosyncratic adverse effects: granulocytopenia, thrombocytopenia, liver toxicity, aplastic anemia
	Adjunctive therapy for focal-onset seizures with or without focal-to-bilateral tonic-clonic generalization Contraindicated in patients with familial short QT syndrome	Dizziness, diplopia, somnolence, fatigue Rarely, medication reaction with eosinophilia and systemic symptoms (DRESS), shortening of QT interval, suicidal ideation
	Absence seizures Adjunctive therapy for tonic or atonic seizures in Lennox-Gastaut syndrome and for refractory focal-onset seizures with or without focal-to-bilateral tonic-clonic generalization	Somnolence, sedation, constipation, ataxia, suicidal thoughts, medication dependency, irritability, dysphagia
	Atypical absence seizures in Lennox-Gastaut syndrome, atonic and myoclonic seizures, epileptic spasms	Drowsiness, ataxia, behavioral abnormalities, partial or complete tolerance to beneficial effects, usually in 1 to 6 months*
Divalproex	Same indications as valproate: Absence seizures (typical and atypical), focal-onset seizures, tonic-clonic seizures, myoclonic seizures, juvenile myoclonic epilepsy, epileptic spasms, neonatal or febrile seizures, tonic or atonic seizures in Lennox-Gastaut syndrome	Nausea, vomiting, GI intolerance, weight gain, reversible alopecia, transient drowsiness, transient neutropenia, tremor Idiosyncratically, hyperammonemic encephalopathy Rarely, fatal hepatic necrosis, particularly in young neurologically impaired children treated with multiple antiseizure medications
	Focal-onset seizures as monotherapy or adjunctive therapy Not recommended for use in patients with severe hepatic impairment	Dizziness, diplopia, somnolence, hyponatremia, suicidal ideation, dermatologic reactions (including Stevens-Johnson syndrome); significant medication reactions possible
	Absence seizures	Nausea, lethargy, dizziness, headache Idiosyncratically, leukocytopenia or pancytopenia, dermatitis, systemic lupus erythematosus
	Refractory focal-onset seizures, atypical absence seizures in Lennox-Gastaut syndrome	Headache, fatigue, liver failure; rarely, aplastic anemia
	Status epilepticus	Ataxia, dizziness, somnolence, headache, pruritus, paresthesias
	Adjunctive therapy for focal-onset seizures in patients aged 3 to 12 years and as adjunctive therapy for focal-onset seizures with or without focal-to-bilateral tonic-clonic seizures in patients aged ≥ 12 years	Drowsiness, dizziness, weight gain, headache In patients aged 3 to 12 years, somnolence, aggressive behavior, mood lability, hyperactivity
	Second-line monotherapy or adjunctive therapy for focal-onset seizures in patients ≥ 17 years Adjunctive therapy for primary generalized tonic-clonic seizures in patients ≥ 4 years	Dizziness, diplopia, suicidal thoughts
	Adjunctive therapy for focal-onset seizures in patients ≥ 2 years, generalized-onset seizures in Lennox-Gastaut syndrome, generalized-onset tonic-clonic seizures	Headache, dizziness, drowsiness, insomnia, fatigue, nausea, vomiting, diplopia, ataxia, tremor, menstrual abnormalities, rash (in 2 to 3%), which progresses to Stevens-Johnson syndrome in 1/50 to 100 children and 1/1000 adults Exacerbation of myoclonic seizures in adults
	Status epilepticus Adjunctive therapy for focal-onset seizures in patients ≥ 4 years, generalized-onset tonic-clonic seizures in patients > 6 years, myoclonic seizures in patients > 12 years, and juvenile myoclonic epilepsy	Fatigue, weakness, ataxia, mood and behavioral changes
	Focal-onset seizures in patients aged 4 to 16 years as adjunctive therapy and for focal-onset seizures in adults	Fatigue, nausea, abdominal pain, headache, dizziness, somnolence, leukopenia, diplopia, hyponatremia (in 2.5%).
	Adjunctive therapy for focal-onset seizures and generalized-onset tonic-clonic seizures in people who have epilepsy and are ≥ 12 years Not indicated for use in children < 4 years	Aggressiveness, mood and behavioral changes, suicidal ideation, dizziness, somnolence, fatigue, irritability, falls, headache, nausea, vomiting, abdominal pain, weight gain, gait disturbances
	Generalized-onset tonic-clonic seizures, focal-onset seizures, status epilepticus, neonatal seizures	Drowsiness, nystagmus, ataxia, In children, learning difficulties, paradoxical hyperactivity Idiosyncratically, anemia, rash
	Focal-to-bilateral tonic-clonic seizures, focal impaired-awareness seizures, convulsive status epilepticus Prevention of seizures secondary to head trauma	Megaloblastic anemia, gingival hyperplasia, hirsutism, adenopathy, loss of bone density Idiosyncratically, rash, exfoliative dermatitis Rarely, exacerbation of seizures
	Adjunctive therapy for focal-onset seizures	Dizziness, somnolence, ataxia, blurred vision, diplopia, tremor, weight gain Exacerbation of myoclonic seizures
	Adjunctive therapy for focal-onset seizures in patients ≥ 12 years	Dizziness, light-headedness, confusion, slowed thinking, fatigue, tremor, sedation, nausea, abdominal pain
	Focal-onset seizures in patients ≥ 2 years, atypical absence seizures Second-line monotherapy or adjunctive therapy for primarily generalized tonic-clonic seizures	Decreased concentration, paresthesias, fatigue, speech dysfunction, confusion, anorexia, weight loss, reduced sweating, metabolic acidosis, nephrolithiasis (in 1 to 5%), psychosis (in 1%)
Valproate	Absence seizures (typical and atypical), focal-onset seizures, tonic-clonic seizures, myoclonic seizures, juvenile myoclonic epilepsy, epileptic spasms, neonatal or febrile seizures, tonic or atonic seizures in Lennox-Gastaut syndrome Status epilepticus Not generally recommended for women of childbearing age	Nausea, vomiting, GI intolerance, weight gain, reversible alopecia (in 5%), transient drowsiness, transient neutropenia, tremor Idiosyncratically, hyperammonemic encephalopathy Rarely, fatal hepatic necrosis, particularly in young neurologically impaired children treated with multiple antiseizure medications
	Adjunctive therapy for focal-onset seizures Epileptic spasms	Drowsiness, dizziness, headache, fatigue, irreversible visual field defects (requires regular visual field evaluations)
	Adjunctive therapy for focal-onset seizures in patients ≥ 16 years, alternative or adjunctive therapy for tonic or atonic seizures in Lennox-Gastaut syndrome	Depression, psychosis, urinary calculi, oligohidrosis

Medication Name

Indications

Adverse Effects

Refractory absence seizures

Renal calculi, dehydration, metabolic acidosis

Adjunctive therapy for seizures in Lennox-Gastaut syndrome and Dravet syndrome in patients ≥ 2 years

Somnolence, hepatocellular injury with elevated aminotransferases, anorexia, fatigue, insomnia, diarrhea

Focal-onset, generalized-onset tonic-clonic, and mixed seizures (but not absence, myoclonic, or atonic seizures)

Diplopia, dizziness, nystagmus, gastrointestinal (GI) upset, dysarthria, lethargy, low white blood cell (WBC) count (3000 to 4000/mcL), hyponatremia, severe rash, including Stevens-Johnson syndrome (in 5%)

Idiosyncratic adverse effects: granulocytopenia, thrombocytopenia, liver toxicity, aplastic anemia

Adjunctive therapy for focal-onset seizures with or without focal-to-bilateral tonic-clonic generalization

Contraindicated in patients with familial short QT syndrome

Dizziness, diplopia, somnolence, fatigue

Rarely, medication reaction with eosinophilia and systemic symptoms (DRESS), shortening of QT interval, suicidal ideation

Absence seizures

Adjunctive therapy for tonic or atonic seizures in Lennox-Gastaut syndrome and for refractory focal-onset seizures with or without focal-to-bilateral tonic-clonic generalization

Somnolence, sedation, constipation, ataxia, suicidal thoughts, medication dependency, irritability, dysphagia

Atypical absence seizures in Lennox-Gastaut syndrome, atonic and myoclonic seizures, epileptic spasms

Drowsiness, ataxia, behavioral abnormalities, partial or complete tolerance to beneficial effects, usually in 1 to 6 months*

Divalproex

Same indications as valproate: Absence seizures (typical and atypical), focal-onset seizures, tonic-clonic seizures, myoclonic seizures, juvenile myoclonic epilepsy, epileptic spasms, neonatal or febrile seizures, tonic or atonic seizures in Lennox-Gastaut syndrome

Nausea, vomiting, GI intolerance, weight gain, reversible alopecia, transient drowsiness, transient neutropenia, tremor

Idiosyncratically, hyperammonemic encephalopathy

Rarely, fatal hepatic necrosis, particularly in young neurologically impaired children treated with multiple antiseizure medications

Focal-onset seizures as monotherapy or adjunctive therapy

Not recommended for use in patients with severe hepatic impairment

Dizziness, diplopia, somnolence, hyponatremia, suicidal ideation, dermatologic reactions (including Stevens-Johnson syndrome); significant medication reactions possible

Absence seizures

Nausea, lethargy, dizziness, headache

Idiosyncratically, leukocytopenia or pancytopenia, dermatitis, systemic lupus erythematosus

Refractory focal-onset seizures, atypical absence seizures in Lennox-Gastaut syndrome

Headache, fatigue, liver failure; rarely, aplastic anemia

Status epilepticus

Ataxia, dizziness, somnolence, headache, pruritus, paresthesias

Adjunctive therapy for focal-onset seizures in patients aged 3 to 12 years and as adjunctive therapy for focal-onset seizures with or without focal-to-bilateral tonic-clonic seizures in patients aged ≥ 12 years

Drowsiness, dizziness, weight gain, headache

In patients aged 3 to 12 years, somnolence, aggressive behavior, mood lability, hyperactivity

Second-line monotherapy or adjunctive therapy for focal-onset seizures in patients ≥ 17 years

Adjunctive therapy for primary generalized tonic-clonic seizures in patients ≥ 4 years

Dizziness, diplopia, suicidal thoughts

Adjunctive therapy for focal-onset seizures in patients ≥ 2 years, generalized-onset seizures in Lennox-Gastaut syndrome, generalized-onset tonic-clonic seizures

Headache, dizziness, drowsiness, insomnia, fatigue, nausea, vomiting, diplopia, ataxia, tremor, menstrual abnormalities, rash (in 2 to 3%), which progresses to Stevens-Johnson syndrome in 1/50 to 100 children and 1/1000 adults

Exacerbation of myoclonic seizures in adults

Status epilepticus

Adjunctive therapy for focal-onset seizures in patients ≥ 4 years, generalized-onset tonic-clonic seizures in patients > 6 years, myoclonic seizures in patients > 12 years, and juvenile myoclonic epilepsy

Fatigue, weakness, ataxia, mood and behavioral changes

Focal-onset seizures in patients aged 4 to 16 years as adjunctive therapy and for focal-onset seizures in adults

Fatigue, nausea, abdominal pain, headache, dizziness, somnolence, leukopenia, diplopia, hyponatremia (in 2.5%).

Adjunctive therapy for focal-onset seizures and generalized-onset tonic-clonic seizures in people who have epilepsy and are ≥ 12 years

Not indicated for use in children < 4 years

Aggressiveness, mood and behavioral changes, suicidal ideation, dizziness, somnolence, fatigue, irritability, falls, headache, nausea, vomiting, abdominal pain, weight gain, gait disturbances

Generalized-onset tonic-clonic seizures, focal-onset seizures, status epilepticus, neonatal seizures

Drowsiness, nystagmus, ataxia,

In children, learning difficulties, paradoxical hyperactivity

Idiosyncratically, anemia, rash

Focal-to-bilateral tonic-clonic seizures, focal impaired-awareness seizures, convulsive status epilepticus

Prevention of seizures secondary to head trauma

Megaloblastic anemia, gingival hyperplasia, hirsutism, adenopathy, loss of bone density

Idiosyncratically, rash, exfoliative dermatitis

Rarely, exacerbation of seizures

Adjunctive therapy for focal-onset seizures

Dizziness, somnolence, ataxia, blurred vision, diplopia, tremor, weight gain

Exacerbation of myoclonic seizures

Adjunctive therapy for focal-onset seizures in patients ≥ 12 years

Dizziness, light-headedness, confusion, slowed thinking, fatigue, tremor, sedation, nausea, abdominal pain

Focal-onset seizures in patients ≥ 2 years, atypical absence seizures

Second-line monotherapy or adjunctive therapy for primarily generalized tonic-clonic seizures

Decreased concentration, paresthesias, fatigue, speech dysfunction, confusion, anorexia, weight loss, reduced sweating, metabolic acidosis, nephrolithiasis (in 1 to 5%), psychosis (in 1%)

Valproate

Absence seizures (typical and atypical), focal-onset seizures, tonic-clonic seizures, myoclonic seizures, juvenile myoclonic epilepsy, epileptic spasms, neonatal or febrile seizures, tonic or atonic seizures in Lennox-Gastaut syndrome

Status epilepticus

Not generally recommended for women of childbearing age

Nausea, vomiting, GI intolerance, weight gain, reversible alopecia (in 5%), transient drowsiness, transient neutropenia, tremor

Idiosyncratically, hyperammonemic encephalopathy

Rarely, fatal hepatic necrosis, particularly in young neurologically impaired children treated with multiple antiseizure medications

Adjunctive therapy for focal-onset seizures

Epileptic spasms

Drowsiness, dizziness, headache, fatigue, irreversible visual field defects (requires regular visual field evaluations)

Adjunctive therapy for focal-onset seizures in patients ≥ 16 years, alternative or adjunctive therapy for tonic or atonic seizures in Lennox-Gastaut syndrome

Depression, psychosis, urinary calculi, oligohidrosis

In these topics

Antiseizure Medications