[Disturbances of calcium-phosphate-metabolism by anticonvulsant drugs in relation to their serum concentration (author's transl)].

25.6% of 254 epileptic children receiving anticonvulsant drugs more than 3 years showed disturbances of Calcium-phosphate-metabolism and of ossification respectively. These disturbances are divided into 4 degrees of severity: 1. Raised alkaline phosphatase in serum alone 21 patients); 2. Metaphysial osteodystrophia (22 Pat.); 3. Generalised osteoporosis (16 Pat.) and 4. Vitamin-D sensitive rickets (6 Pat.). These abnormalities were found at most in long term-treatment with hydantoins or primidone. The measurement of serum concentration of these anticonvulsant drugs yielded significantly higher amounts in patients with abnormalities in Calcium-Phosphate-metabolism than in those patients without such ones. This result permits us to conclude that disturbances of Calcium-Phosphate-metabolism are serum-concentration-dependent side-effects of anticonvulsant drugs.