Mechanism of Captopril-Induced Agranulocytosis

Abstract

A case of reversible agranulocytosis in a young captopril treated patient with renovascular hypertension who was otherwise in good health is reported. Captopril was the only drug administered. Coculturing the patient’s bone-marrow with captopril in concentrations up to 10⁴ M did not influence colony nor cluster growth at 11 days of culture. This result suggests that captopril exerts its myelotoxic effect via an indirect mechanism. The associated serum-sickness-like syndrome, the transient development of antinuclear antibodies, and the finding of circulating immune complexes support the hypothesis of a captopril induced immunodysregulation, leading to agranulocytosis.