 to see patients receiving the thiocarbamides at least monthly during the initiation of therapy and every two to three months during the entire program. Neutropenia can develop gradually but often comes on so suddenly that a routine white cell count offers only partial protection. A white cell count must be taken whenever there is any suggestion of a reaction, and especially if the patient reports malaise or a sore throat. A white cell count taken at each visit will detect the gradually developing neutropenia that may occur. While many physicians do not routinely monitor these levels, the value of monitoring is suggested by the study of Tajiri et al . Fifty-five of 15398 patients treated with antithyroid drugs developed agranulocytosis, and 4/5 of these were detected by routine WBC at office visits. Low total leukocyte counts are common in Graves’ disease because of relative neutropenia, and for this reason a baseline WBC and differential should be performed before starting anti-thyroid drugs. However, total polymorphonuclear counts below 2,000 cells/mm3 should be carefully monitored; below 1,200 cells/mm3 it is unsafe to continue using the drugs.
In the event of severe neutropenia or agranulocytosis, the patient should be monitored closely, given antibiotics if infection develops, and possibly adrenal steroids. There is no consensus on the use of glucocorticoids, since they have not been shown to definitely shorten the period to recovery. Administration of recombinant human granulocyte colony stimulating factor (75 µg/day given IM) appears to hasten neutrophile recovery in most patients who start with neutrophile counts > 0.1 X 109/L . Antithymocyte globulin and cyclosporin are also used [153.1]. Care must be taken to ensure against exposure to infectious agents, and some physicians prefer not to hospitalize their patients for this reason. If the patient is hospitalized, he or she should be placed in a special-care room with full bacteriologic precautions.
Patients may develop antineutrophil cytoplasmic antibodies, either pericytoplasmic or cytoplasmic, during treatment, with or without vasculitis. Most cases appear to be associated with the use of propylthiouracil, and therapy includes cessation of the drug, sometimes treatment with steroids or cyclophosphamide for renal involvement, and rarely plasmapheresis. The commonest cutaneous lesion associated is leukocytoclastic vasculitis associated with purpuric lesions. Symptoms may include fever, myalgia, arthralgia, and lesions in the kidneys and lungs. Prognosis is usually good if the medication is discontinued, although death has occurred. ANCA positivity (pericytoplasmic, cytoplasmic, directed to myeloperoxidase, proteinase3, or human leukocyte elastase) can occur in patients on antithyroid drugs associated with vasculitis. It is also found without clinical evidence of vasculitis, and the significance of this finding is unclear [149.1]. Guma et al recently reported that, in a series of patients with Graves’ disease, 67% were found to be ANCA positive before medical treatment, and that 19% remained positive after one year of antithyroid treatment. This data suggests that ANCA antibodies reflect in some way the autoimmunity associated with Graves’ hyperthyroidism, rather than simply being a manifestation due to the treatment with antithyroid drugs (149.2). In addition to suppression of hematopoiesis and agranulocytosis, methimazole has been associated in one patient with massive plasmocytosis, in which 98% of the cells in the bone marrow were plasma cells. After discontinuation of the drug, and treatment with dexamethasone and G-CSF, the patient’s marrow recovered to normal (149.1).
Liver damage-Thiocarbamides can also cause liver damage ranging from elevation of enzymes, through jaundice, to fatal hepatic necrosis
Toxic hepatitis (primarily with propylthiouracil) and cholestatic jaundice (primarily with methimazole) are fortunately uncommon .Toxic hepatitis can be severe or fatal, but the incidence of serious liver complications is so low that routine monitoring of func