Chromosomal studies of peripheral blood from epileptic patients treated with phenobarbital and/or diphenylhydantoin.

Chromosome studies were carried out on the peripheral blood of 26 epilepsy patients treated with phenobarbital and/or diphenylhydantoin, on ten healthy controls and on eight untreated epileptic controls. There was a significant increase in the individual numbers of sister chromatid exchanges per metaphase for all the patients treated with drugs compared with the mean of the pooled values from all the controls. There was no significant increase in the number of chromosome aberrations in the treated patients compared with the controls. There were very few structural aberrations in either the treated patients or the controls.