Carbamazepine and Lithium Carbonate Synergism in Mania

To the Editor.— Moss and James1presented an interesting case of an acute but unsustained antimanic response to the combination of carbamazepine and lithium carbonate. Several points raised in their letter deserve comment and further discussion. There are many potential reasons for the lack of a continued response to carbamazepine in combination with lithium carbonate in their case. One is dosage. The 800-mg/day dosage they employed was slightly below the average dosage in our series, with many patients being able to tolerate a higher dosage without evidence of side effects and achieving more impressive clinical responses.2,3The authors noted that increases in dosage were postponed because of a trend indicating slight suppression of bone marrow activity. Mild to moderate decreases in WBC count are evident in the majority of patients treated with carbamazepine; this appears to be, in part, dose related but is not thought to be related