Quinidine induced lupus syndrome.

Five patients with a lupus-like syndrome secondary to quinidine are described. Eleven other cases have previously been reported. The quinidine induced lupus syndrome is similar to that seen with procainamide and hydralazine treatment but occurs less frequently. The lower incidence may reflect a difference in the metabolism of quinidine. Quinidine should be considered as potentially responsible when multisystem disease appears in patients receiving this drug.