Continue checkpoint inhibitor therapy Endocrine referral Hyperthyroidism may require medical management, if symptoms exist, but with close monitoring as this phase is usually short-lived Onset of hypothyroid phase (generally by week 9 of treatment): Commence thyroxine 50–100 mcg/daily Increase by 50 mcg in 3 weeks if TSH is still high until TSH is within normal range Continue thyroxine maintenance dose
Consider delay of checkpoint inhibitor therapy Prednisolone 1 mg/kg/day Taper glucocorticoid to maintenance oral hydrocortisone (e.g., 10 mg hysone 0600/1500) It will generally require lifelong physiological replacement of steroid Adrenal sick day education Commence thyroxine/gonadal hormone replacement if required
Grade 3-4/severe/life-threatening
Hypophysitis (adrenal crisis: fatigue, headache, dizziness, hypotension, and hypoglycaemia shock)
Delay checkpoint inhibitor therapy Urgent endocrine review Pulse with methylprednisolone 1-2 mg/kg/day if indicated (e.g., headache); or high dose intravenous glucocorticoids (i.e., hydrocortisone 50 mg QID) Manage/exclude sepsis Fluid replacement Taper glucocorticoid to maintenance oral hydrocortisone (e.g., 10 mg hysone 0600/1500) It will generally require lifelong physiological replacement of steroid Adrenal sick day education Commence thyroxine/gonadal hormone replacement if required
Ensure steroid repletion prior to initiation of thyroxine to avoid precipitating adrenal crisis. Gonadal hormone replacement therapy can be initiated nonurgently when hypogonadotropic hypogonadism (secondary to hypophysitis) is confirmed to be persistent.
