The frequency of bone abnormality in patients on anticonvulsant therapy.

Biochemical and bone morphometric measurements were evaluated in 12 patients who were on long-term anticonvulsant therapy with barbiturates. Half of the patients had no symptomatic bone disease, and half presented with bone disease and pain. Serum biochemical values were normal except for a few patients who had an elevated serum level of parathyroid hormone; the concentration of serum 25-hydroxy vitamin D was decreased in the majority of patients in whom it was measured. Bone absorptiometric values were normal but proved to be misleading: the Singh Index and videodensitometric measurements indicated that bone mass was below normal in all patients. Bone morphometric data indicated that bone resorption was 3 times greater than normal, and there was no evidence of osteomalacia. Vitamin D and possibly calcium have been suggested as potentially useful agents in the treatment of the bone disease associated with chronic anticonvulsant therapy.