This handout is for acute hf — thyrotoxicosis-induced (high-output). Your care team identified this based on: tsh <0.01 + elevated free t4 or t3 + hf symptoms (dyspnea, edema, orthopnea) → thyrotoxic hf pathway.
Other reasons your team may use this plan: new afib with rapid ventricular response + features of thyrotoxicosis (heat intolerance, weight loss, tremor, lid lag, exophthalmos) — check tsh urgently; recent amiodarone exposure or iodinated contrast within 6-8 weeks + new thyrotoxicosis + hf — jod-basedow / amiodarone-induced thyrotoxicosis; burch-wartofsky ≥45 (fever, ams, gi, severe tachycardia, hf) → thyroid storm — life-threatening decompensation.
Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.
| Medication | Starting dose | How | When | What it does |
|---|---|---|---|---|
| propranolol | 40 mg PO q4-6h (titrate to HR <100); IV 0.5-1 mg q5min in severe tachycardia (max 5 mg) | PO/IV | q4-6h titrate | ATA 2016 — first-line for symptomatic relief + reduces peripheral T4→T3 conversion (unique to nonselective BB at higher doses); PRIMARY benefit even before thionamide takes effect (days-weeks) |
| esmolol | 500 µg/kg IV bolus then 50-200 µg/kg/min infusion | IV | continuous infusion | Titratable IV BB for storm with severe tachycardia or potential decompensation; rapid offset allows reversal if pulmonary edema worsens |
| methimazole | 20-30 mg PO daily (single or divided dose); 60-80 mg/d in storm | PO | daily or BID-TID in storm | ATA 2016 first-line outside pregnancy first trimester due to PTU hepatotoxicity; once-daily dosing improves adherence; longer half-life than PTU |
| propylthiouracil_PTU | 100 mg PO q8h (300 mg/d); 200 mg q4h (1200 mg/d) in storm | PO | q8h or more frequent in storm | PTU PREFERRED in first trimester (lower teratogenicity than methimazole) + in storm (more rapidly blocks peripheral T4→T3 conversion); BLACK BOX for hepatotoxicity outside these indications |
| potassium_iodide_lugol_solution | Lugol solution 5 drops (250 mg iodine) PO q8h OR SSKI 5 drops PO q8h | PO | q8h × 7-10 d | ATA 2016 thyroid storm Class I — Wolff-Chaikoff effect blocks hormone release; MUST give ≥1 h AFTER thionamide to prevent escape (substrate for new synthesis); also pre-op prep for thyroidectomy (reduces gland vascularity) |
| hydrocortisone | 100 mg IV q8h (300 mg/d total) — also dexamethasone 2 mg IV q6h alternative | IV | q8h | ATA 2016 storm Class IIa — reduces peripheral T4→T3 conversion + adrenal support (relative adrenal insufficiency in storm); also primary therapy for amiodarone type 2 thyrotoxicosis (destructive thyroiditis) |
| cholestyramine | 4 g PO QID | PO | QID | Binds enterohepatic T4 to lower circulating hormone; useful in storm with very high T4 levels; safe + cheap adjunct |
| furosemide | 20-40 mg IV (NOT 80-160 — high-output state with often hyperdynamic SVR) titrate to UOP | IV | q8-12h titrate | Standard loop for congestion in HF; gentler dosing in high-output failure (less LV systolic dysfunction; over-diuresis worsens hyperdynamic state) |
| apixaban | 5 mg PO BID (2.5 mg BID if 2 of 3 dose-reduction criteria) | PO | BID | AFib in thyrotoxicosis is independent stroke risk factor; ACC/AHA 2023 (PMID 38033089) — DOAC preferred over warfarin in non-valvular AFib; apixaban favored in elderly per ARISTOTLE |
| digoxin | 0.125-0.25 mg PO daily (renal-adjusted; target serum 0.5-0.9 ng/mL) | PO | daily | Add-on rate control if BB insufficient (thyrotoxicosis often resistant to digoxin alone — increased renal clearance + decreased receptor affinity); narrow therapeutic window |
Plan: Thyrotoxicosis-induced high-output HF — BB + thionamide + iodine + steroid (in storm) + supportive HF (ATA 2016 PMID 27521067; JCEM 2023 storm; Klein NEJM 2001)
Contact your care team if any of the following happen:
Call 911 or go to the nearest emergency room right away if you have:
Endocrinology weekly/biweekly during titration; cardiology for HF management + AFib; definitive therapy planning (RAI vs thyroidectomy vs continued medical for Graves) at 12-18 mo if remission; LFT monitoring weekly × 4 then monthly on PTU; CBC at any infection/sore throat (agranulocytosis); BB withdrawal as euthyroidism achieved + HR normalizes
Guideline: ATA 2016 thyrotoxicosis (Ross PMID 27521067) + JCEM 2023 thyroid storm + 2022 ACC/AHA HF + 2023 ACC/AHA AFib