Eosinophilia in D-penicillamine therapy.

Cross-sectional and longitudinal studies have been carried out to determine the incidence and clinical significance of eosinophilia in patients taking penicillamine for rheumatoid arthritis. In a cross-sectional study of 204 patients eosinophilia was found with equal frequency during treatment with penicillamine, gold, and nonsteroidal anti-inflammatory drugs. A longitudinal study of 89 patients treated with penicillamine showed no consistent relationship between eosinophilia and adverse reactions to the drug. It is concluded that routine monitoring of eosinophil counts is unlikely to be of value in the management of patients taking penicillamine.