Lithium is an ineffective therapy for human cyclic hematopoiesis.

Cyclic hematopoiesis is a rare disease in man in which severe neutropenia recurs at 21-day intervals with associated illness. Because lithium carbonate therapy has been shown to eliminate cyclic hematopoiesis in grey collie dogs, we examined the effects of lithium treatment on five patients with this disease. With lithium levels maintained between 0.5 and 1.0 meq/liter, these patients showed no change in the fluctuations of their neutrophil counts. We conclude that lithium carbonate is not a simple cure for human cyclic hematopoiesis.