Levothyroxine toxicity: Difference between revisions
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==Management== | ==Management== | ||
* | *Mirrors the treatment for [[thyroid storm]] with the exception of antithyroid drugs which offer little potential benefit with the exception of [[propranolol]] | ||
===Agitation=== | |||
*Best treated with [[benzodiazepines]] | |||
===Catecholamine Excess=== | |||
*[[Propranolol]] 1 to 2 mg IV every 10 to 15 minutes are recommended | |||
===Hyperthermia=== | |||
*Aspirin, should be avoided because it carries a theoretical risk of thyrotoxicity by displacing T3 and T4 from thyroxine-binding globulin. | |||
*External cooling is the best means to treat severe hyperthermia in addition consideration of intubation with sedation and continued paralysis. | |||
===Drug Removal=== | |||
*[[Plasma exchange]] or [[plasmapheresis]] can be used in the most severe of poisonings<re>Van Huekelom S, et al Plasmapheresis in L-thyroxine intoxication. Vet Hum Toxicol.1979;s21:7</ref> | |||
==Disposition== | ==Disposition== | ||
*Symptomatic patients should be admitted for observation | |||
==See Also== | ==See Also== | ||
*[[Thyroid disease]] | |||
*[[Thyroid storm]] | |||
==External Links== | ==External Links== | ||
Latest revision as of 22:11, 14 January 2022
Background
- Most acute thyroxine overdoses are mild.
- Chronic ingestions are more likely to present with clinical symptoms similar to thyrotoxicosis
- Diet pills such as Singaporean Slim 10[1] and athletic stimulant compounds can contain large amounts of T3/T4
- Thyrotoxicosis factitia - also known as thyroxine addict or metabolic malingerer where large doses of thyroid supplementation is taaking for weight loss or stimulation
Clinical Features
Although most thyroxine ingestions are mild, large acute or chronic ingestions can mirror moderate to severe thyrotoxicosis
Classic Triad
- Hyperthermia
- Often marked (40 - 41C)[2]
- Tachycardia
- Often out of proportion to fever [3]
- Altered mental status (agitation, confusion, delirium stupor, coma, seizure)
May also have:
- Goiter
- Thyrotoxic stare, lid retraction
- Hyperhidrosis
- Thermoregulatory dysfunction
- Central nervous system dysfunction
- Gastrointestinal-hepatic dysfunction
- Diarrhea, nausea and vomiting, abdominal pain
- Unexplained jaundice, hepatomegaly
- Cardiovascular dysfunction
- Tachycardia, palpitations
- Congestive heart failure, dyspnea
- Pedal edema
- A. fib
- Widened pulse pressure
Differential Diagnosis
- Sympathomimetic ingestion
- Atherosclerosis
- Aortic regurgitation
- Thyrotoxicosis
- Fever
- Anemia
- Pregnancy
- Anxiety
- Patent ductus arteriosus
- Heart block
- Aortic dissection
- Endocarditis
- Increased ICP
- Vasodilating drugs
- Beriberi
- Pheochromocytoma
Evaluation
- Workup and diagnosis will follow that for thyrotoxicosis
Management
- Mirrors the treatment for thyroid storm with the exception of antithyroid drugs which offer little potential benefit with the exception of propranolol
Agitation
- Best treated with benzodiazepines
Catecholamine Excess
- Propranolol 1 to 2 mg IV every 10 to 15 minutes are recommended
Hyperthermia
- Aspirin, should be avoided because it carries a theoretical risk of thyrotoxicity by displacing T3 and T4 from thyroxine-binding globulin.
- External cooling is the best means to treat severe hyperthermia in addition consideration of intubation with sedation and continued paralysis.
Drug Removal
- Plasma exchange or plasmapheresis can be used in the most severe of poisonings<re>Van Huekelom S, et al Plasmapheresis in L-thyroxine intoxication. Vet Hum Toxicol.1979;s21:7</ref>
Disposition
- Symptomatic patients should be admitted for observation
See Also
External Links
References
- ↑ Hedberg CW: An outbreak of thyrotoxicosis caused by the consumption of bovine thyroid gland in ground beef. N Engl J Med. 1987;316:993–998.
- ↑ Thiessen, M. (2018). Thyroid and Adrenal Disorders in Rosen's emergency medicine: Concepts and clinical practice (9th ed.). Philadelphia, PA: Elsevier/Saunders.
- ↑ Thiessen, M. (2018). Thyroid and Adrenal Disorders in Rosen's emergency medicine: Concepts and clinical practice (9th ed.). Philadelphia, PA: Elsevier/Saunders.