This chapter will review the pharmacologic management of adrenal and thyroid dysfunction according to the clinical practice guidelines and expert opinion.
Thyroid storm
Definition
A life-threatening condition caused by an excess of thyroid hormone resulting in cardiovascular and central nervous system dysfunction and hyperpyrexia.
Precipitating factors
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Abrupt discontinuation of antithyroid medications
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Acute illness (sepsis/infection, surgery or trauma)
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Graves’ disease
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Radioiodine therapy
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Parturition
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Drugs (salicylates, amiodarone, anesthetics, pseudoephedrine)
Pharmacologic management ( table 7.1 )
| DRUG | STANDARD DOSING | COMMENTS |
|---|---|---|
| Thionamides: Decrease Thyroid Hormone Synthesis | ||
| Propylthiouracil | PO: 500–1000 mg ×1 then 250 mg q4h | First-line Decrease conversion of T4 to T3 Preferred in pregnant or lactating women ADR: agranulocytosis (rare), bleeding, hepatotoxicity, renal failure, vasculitis |
| Methimazole | PO: 20 mg q6–8h | For allergy or intolerance to propylthiouracil ADR: similar to propylthiouracil, but less hepatotoxicity than propylthiouracil |
| Iodine: Inhibit Thyroid Hormone Release | ||
| Saturated solution of potassium iodide (SSKI) | PO: 5 drops q6h PR: 250–500 mg q6h | Start 1 h after thionamide started to prevent iodine serving as a substrate for new thyroid hormone production and worsening hyperthyroidism Use in conjunction with thionamides |
| Lugol solution | PO: 8 drops q6h PR: 5–10 drops q8–6h | |
| Lithium | PO: 300 mg q6–8h | Reserve for patients with iodine intolerance or CI Goal: 0.6–1 mEq/L Avoid in CrCl <30 |
| β-Blockers: Control Heart Rate | ||
| Propranolol | PO: 60–80 mg q4–6h IV: 0.5–1 mg over 10 min ×1 then 1–2 mg over 10 min PRN | Caution in congestive heart failure Decrease conversion of T4 to T3 at high doses Use with caution in renal/hepatic impairment |
| Esmolol | 250–500 mcg IV ×1 then 50–100 mcg/kg/min | Short-acting Rapid-titration |
| Bile Acid Sequestrants: Decrease Enterohepatic Recycling of Thyroid Hormones | ||
| Cholestyramine | PO: 1–4 g BID | Off-label use. Use with a thionamide and propranolol |
| Glucocorticoids: Decrease Conversion of T4 to T3 | ||
| Hydrocortisone | IV: 300 mg ×1 then 100 mg q8h | Adjunct therapy Alternative: Dexamethasone 1–2 mg q6h |
| ||
Myxedema coma
Definition
Severe hypothyroidism characterized by decreased mental status, hypothermia, cardiovascular instability, hyponatremia, hypoglycemia, and hypoventilation.
Risk factors
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Noncompliance to thyroid replacement therapy
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Chronic hypothyroidism
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Infection
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Myocardial infarction
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Cold exposure
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Surgery
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Drugs (sedatives, opioids, amiodarone, lithium)
Management
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Supportive care
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Treat underlying etiology
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Pharmacologic management ( Table 7.2 )
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