Читать книгу Blood and Marrow Transplantation Long Term Management - Группа авторов - Страница 139

Cushingoid appearance most often results from prolonged prednisone therapy; cosmetic changes are troubling for patients, and especially for teenagers who are often already dealing with major changes of body image. Counseling may be helpful that these changes are mostly reversible, given enough time off steroids. Divided‐dose prednisone regimens should be avoided for cGVHD due to greater adrenal suppression than daily or alternating‐day regimens. Abrupt withdrawal of steroids may provoke symptoms of secondary adrenal insufficiency, which should be anticipated in any patient treated for more than 3 weeks with daily doses exceeding 7.5 mg of prednisone or equivalent. Blunted cortisol response may be life threatening when stress responses are needed. Because mineralocorticoid deficiency is not present hyperkalemia does not usually occur. Symptoms of adrenal insufficiency are usually dominated by fatigue and weakness but may be difficult to distinguish from a flare of GVHD or, steroid withdrawal syndrome; the latter is dominated by arthralgias and myalgias and tends to stabilize if taper decrements are smaller. Adrenal insufficiency may be confirmed by showing that serum cortisol at 07:00–09:00 hours is <3.6 mcg/dL or the serum cortisol at 30 or 60 minutes after a standard cosyntropin test dose (250 mcg IV) does not increase >19 mcg/dL [108–110]. Hydrocortisone 8 mg/m² to 12 mg/m² per day is the preferred adrenal cortisol replacement therapy. The total dose is usually divided into two to three daily doses, with half to two‐thirds of the daily dose administered at 08:00h to mimic the physiologic cortisol secretion pattern and lower doses at either 12:00h and 17:00h (or just 17:00h). The exact dose regimen is adjusted according to symptoms and signs suggestive of over‐ or under‐replacement. Though prednisone is recommended for the treatment of primary adrenal insufficiency, the longer biologic half‐life of prednisone compared to hydrocortisone makes it more likely to suppress the HPA axis. Therefore, hydrocortisone is preferable for replacement therapy in secondary adrenal insufficiency. Stress‐dose steroids should be considered for illnesses that include fever, vomiting, diarrhea, major surgery, or trauma. Recovery of the HPA axis varies from days to several months which must be considered when a taper of replacement therapy is attempted.