Ethosuximide
Commercial names and formulations:
Brand name: Zarontin
Formulations: Syrup, capsule
How to store it?
Store at room temperature
What does the body do to the medication?
Can I take it with food?
Yes
How long does it take to get to the blood after I take it?
3-5 hours
How long does it take to start having a steady effect?
4-10 days
Can this medication be started at a high dose or it has to be started gradually?
Gradually
How long does it stay in the body?
About 1-2 days
How is it eliminated?
Liver
What does the medication do to the body?
Type of epilepsy that helps:
Absence, sometimes myoclonic seizures and Lennox-Gastaut Syndrome, epileptic negative myoclonus
FDA approved for:
Absence epilepsy (petit mal)
Common side effects:
• Skin: hives, rash, abnormal hair growth
• Bones: none
• Blood: decreased white blood cells, decrease in red blood cells
• Liver: none
• Kidneys: none
• Stomach and intestines: weight loss, upset stomach, nausea, vomiting, cramps, abdominal pain, diarrhea
• Heart: none
• Brain: drowsiness, headache, dizziness, lethargy, difficulty with coordination, disturbances of sleep, night terrors, inability to concentrate
• Mood: paranoid psychosis, increased state of depression, euphoria, irritability, hyperactivity, aggressiveness
• Others: allergic reaction, blurred vision, increased libido
Serious side effects:
Abnormal blood conditions
Abnormal liver and kidney function
Systemic lupus erythematosus
Risk of suicidal thoughts or behavior
What happens if I get too much of it (intoxication)?
Acute overdoses may produce nausea, vomiting, and possibly coma with respiratory depression.
What happens if I stop it suddenly (withdrawal)?
Abrupt withdrawal of ethosuximide may cause an increase in seizure activity.
Who should not take this medication?
You should not take this medication if you know that you are allergic to any of the ingredients.
What is the average dose and how many times a day should be given?
Children: age 3-6, 250 mg/day; age 6+, 500mg/day (average dose 20mg/kg/day)
Adults: 20 mg/kg/day
Does the body get used to the medication?
Yes
Medications to be careful with:
Other AEDs that may increase the blood level of ethosuximide:
Valproic Acid will increase it slightly
Other AEDs that may decrease the blood level of ethosuximide:
Phenobarbital, Phenytoin, Primidone, Carbamazepine
Other drug interactions:
Rifampin will decrease level, and isoniazid will increase the level
Blood work required?
CBC and CPM?
Yes
How often?
1-3 months, then less often
Are medication levels in blood useful?
Yes
Normal range
40-100 mcg/mL
Women’s health
Affects contraceptives?
No
Affect fertility?
No
Are safe in pregnancy?
Cases of birth defects have been reported with ethosuximide. Discuss this with your doctor if you are pregnant or plan to become pregnant while taking ethosuximide.
Category
Pregnancy Category D
Can breastfeed?
Ethosuximide is excreted in human breast milk, therefore it should be used with caution in breast-feeding mothers. Behavioral changes in breast-feeding infants have been reported.
Affect bones (osteoporosis)?
No
Men’s health
Affects sexual performance?
No
Affects fertility?
No
Use other than epilepsy:
None