Summary: The carbamazepine (CBZ) concentration of breast milk was determined in 19 epileptic patients of whom 13 were receiving CBZ monotherapy. Two lactation periods under CBZ monotherapy were followed in 2 of these 13 patients. The CBZ concentration of the breast milk was 36.4% of the maternal CBZ serum level (mean value). The correlation coefficient was 0.44; the regression line follows the equation y = 0.12x + 1.63. The CBZ concentration was measured in a total of 50 milk samples during the lactation period (cases of monotherapy plus combination therapy). The CBZ concentration ranged from 1 to 4.8 μg/ml (mean 2.5 μg/ml). The free CBZ concentration in the maternal serum was measured in four patients. The correlation between CBZ in the breast milk and free CBZ levels was 1.6 to 1.8. The ratio of carbam-azepine-epoxide (ECBZ) in the milk to ECBZ determined in serum was 0.53. Continuing galactorrhea after delivery was observed in one patient. The CBZ and ECBZ levels determined 3.5 years after delivery were higher in the milk than in the serum. The observations of breast-fed and non-breast-fed children whose mothers were on CBZ monotherapy disclosed poor suckling in only 1 of 15 infants.

A generalization of the effective stiffness theory of Sun, Achenbach and Herrmann is used to derive a set of approximate equations describing the propagation of a stress wave in a non-linear, geometrically dispersive composite material. The equations which are derived are singular perturbation equations having two kinds of singularities, one caused by dispersion and one caused by the non-linearity. A non-linear dispersion equation which describes the propagation of a periodic wave is derived using an averaged Lagrangian technique developed by Whitham. It is shown that the resulting solution is a simple wave system. With this technique, the singularity associated with the non-linearity may be eliminated and a solution which is convergent beyond the time of shock formation found. Application of this solution to a stress pulse and the group velocity for this system are discussed.