Chromosomal investigations in epileptic children during long-term therapy with phenytoin or primidone.

In epileptic children the long-term therapy with anticonvulsant drugs is absolutely necessary. However, anticonvulsant drugs have been suspected to be mutagenic and teratogenic. To investigate this problem metaphase chromosome observations were performed using short-time culture of peripheral blood lymphocytes from twenty children. Ten of the children had been treated with phenytoin and the other ten with primidone on monotherapy. The long-term administration of anticonvulsant drugs was monitored by measurement of the serum concentrations of phenytoin and primidone, by seizure anamnesis, and by repeated EEG investigations. Analyzing 100 mitoses from each proband, we found no increase of structural or numerical aberrations in our patients compared with six controls. In adults, however, anticonvulsant drugs have been found to cause structural aberrations and chromosomal damage. The absence of these lesions in children may reflect the higher efficiency of DNA-repair in local DNA-damage.