What medications used to treat hyperthyroidism can cause rheumatic syndromes?
• Propylthiouracil—can cause a systemic vasculitis (perinuclear antineutrophil cytoplasmic antibody [ANCA]-positive) and/or drug-induced lupus syndrome. Similar to other drug-induced autoimmune syndromes, the prevalence of autoantibodies is substantially higher than development of clinical signs of autoimmunity.
• Methimazole—can cause a lupus-like syndrome. ANCA antibodies can develop in 10% to 15%, but rarely vasculitis. Reports of developing DM due to anti-insulin antibodies.
