Of all the anticonvulsants, the drug that should be monitored most carefully, or that should be considered “high priority” is . may accumulate in the cerebral cortex with chronic use and can cause atrophy of the cerebellum when administered at high doses. It inhibits the monoglutamate enzyme, thereby causing folate deficiency and predisposing patients to megaloblastic anemia, agranulocytosis, and thrombocytopenia.