Anti-epileptics: Side Effects
- All probably have some effect on behavior and school performance
- phenobarbital causes
cognitive impairment and behavioral side effects most
frequently (in up to 50% of children).
intelligence quotient, decreased attention, depression, or hyperactivity has
been reported in
50% or more of patients receiving phenobarbital. Sedation is dose-related, but
cognitive impairment can be idiosyncratic.
Primidone is metabolized to
phenobarbital and may result in similar effects, especially aggressive
behavior or personality changes.
- least likely to affect behavior and cognitive performance adversely.
acid does not produce rage attacks; in fact, it has been used for their
- can be associated with weight
hepatic failure, particularly in children younger than age 3 years
who are receiving
multiple antiepileptic medications.
- rarely causes significant
leukopenia or hepatotoxicity
and seldom produces hyponatremia.
- Macrolides such as
erythromycin and azithromycin should be
used very cautiously or, if
possible, avoided in children receiving carbamazepine because these
drugs compete for hepatic metabolism, leading to increasing carbamazepine
levels and acute toxicity.
- Phenytoin is similar to
carbamazepine in efficacy for seizures, but it is used less commonly in
children because of significant
cosmetic adverse effects, including
- hirsutism, gingival hyperplasia, and facial coarsening.
- Phenytoin is poorly absorbed from the gastrointestinal tracts of infants
and metabolized at a variable rate in the liver.
- Lamotrigine is used in a
number of refractory seizure disorders and generally is well tolerated
- occasional drowsiness, headache, and blurred vision.
- associated with the development of maculopapular rash that may progress
to Stevens-Johnson syndrome during the early months of use, especially when
administered with valproate. The development of such a rash should prompt
immediate drug discontinuation.
- In an attempt to avoid these reactions, lamotrigine is administered
initially at a low dose and very gradually increased over months,
particularly if valproate also is being administered.
- Gabapentin, a second or
add-on drug for partial seizures, usually is well tolerated.
- not metabolized by the liver and is excreted unchanged by the
kidneys, it has no significant drug interactions.
- Adverse effects include very occasional fatigue, dizziness, headache,
and weight gain.
Benzodiazepines, such as
clonazepam or clorazepate, can produce significant behavioral abnormalities as
well as drowsiness and irritability.
- inhibits carbonic anhydrase, thereby increasing renal excretion of bicarb,
so watch out for metabolic acidosis. Decreases in serum bicarb are mild to
moderate, rarely severe. Acute metabolic acidosis can cause
hyperventilation, fatigue, anorexia, cardiac arrythmias, and stupor.
- monitor serum bicarb when starting therapy or increasing dose. Reduce dose or
dc topamax if metabolic acidosis develops.
Freeman JM, Vining EP, Pillas DJ, eds. Seizures and Epilepsy in Childhood: A
Guide for Parents. 2nd ed. Baltimore, Md: Johns Hopkins University Press; 1997
Freeman JM, Vining EP. Decision making and the child with afebrile
seizures. Pediatr Rev. 1992;13:305-310 Haslam RH. Nonfebrile seizures. Pediatr
Rev. 1997;18:39-49 Haslam RH. Seizures in childhood. In: Behrman RE, Kliegman RM,
Jenson HB, eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia, Pa: WB
Saunders Co; 2000:1813-1829