30
Treatment
Table 4. Endocrine Toxicities
4.1.2 Thyrotoxicosis
Workup/Evaluation:
• TSH can be checked every 4–6 weeks as part of routine clinical monitoring for
asymptomatic patients on ICPi therapy.
• TSH and FT4 should be used for case detection in symptomatic patients. T3 can be
helpful in highly symptomatic patients with minimal FT4 elevations.
• Low TSH with a low FT4 is consistent with central hypothyroidism. Evaluate as per
hypophysitis (see section 4.3).
• Consider TSH receptor antibody testing if there are clinical features and suspicion of
Graves' disease (e.g., ophthalmopathy, T3 toxicosis).
Grading Management
G1: Asymptomatic or mild
symptoms
• Can continue ICPi.
• Beta-blocker (e.g., atenolol or propranolol) for
symptomatic relief.
• Close monitoring of thyroid function every 2–3
weeks after diagnosis to catch the transition to
hypothyroidism, the most common outcome for
transient subacute thyroiditis.
• Treat transition to elevated TSH and low FT4 as
for primary hypothyroidism (see section 4.1.1).
• For persistent thyrotoxicosis (>6 weeks) consider
endocrine consultation for additional work up.
G2: Moderate symptoms,
able to perform ADL
• Consider holding ICPi until symptoms return to
baseline.
• Consider endocrine consultation.
• Beta-blocker (e.g., atenolol or propranolol) for
symptomatic relief.
• Hydration and supportive care.
• For persistent thyrotoxicosis (>6 weeks) refer to
endocrinolog y for additional work up and possible
medical thyroid suppression.
G3–4: Severe symptoms,
medically significant or life-
threatening consequences,
unable to perform ADL
• Hold ICPi until symptoms resolve to baseline with
appropriate therapy.
• Endocrine consultation for all patients.
• Beta-blocker (e.g., atenolol or propranolol).
• Hydration and supportive care.
• Consider hospitalizing patients in severe cases as
in-patient endocrine consultation can guide the use
of additional medical therapies including steroids,
potassium iodide, or thionamide (methimazole or
propylthiouracil) and possible surgery.
(cont'd)
