How does amiodarone cause hypothyroidism and hyperthyroidism?

How does amiodarone cause hypothyroidism and hyperthyroidism?

Amiodarone induces alterations in thyroid hormone levels by actions on thyroidal secretion, on the peripheral tissues, and probably also on the pituitary gland. These actions result in elevations in serum T4 and rT3 concentrations, transient increases in TSH concentrations, and decreases in T3 concentrations.

What is amiodarone induced thyrotoxicosis?

In type 2 AIT, the thyrotoxicosis is a destructive thyroiditis that results in excess release of preformed T4 and T3 into the circulation (11). It typically occurs in patients without underlying thyroid disease, and is caused by a direct toxic effect of amiodarone on thyroid follicular cells.

What is de Quervain’s thyroiditis?

Subacute (DeQuervain’s) thyroiditis is a transient inflammatory thyroid disease usually associated with pain and tenderness of the gland, as well as generalized somatic symptoms, which can cause great discomfort or even complete prostration for weeks or months if left untreated.

Does amiodarone cause hypo or hyperthyroidism?

Amiodarone can lead to both hypothyroidism (amiodarone-induced hypothyroidism) and less commonly hyperthyroidism (amiodarone-induced thyrotoxicosis) and relates to high iodine content within the molecule as well as to several unique intrinsic properties of amiodarone.

Why does amiodarone cause hypotension?

In the acute setting, amiodarone can cause hypotension due to vasodilation and depression of myocardial contractility; this may be partly due to the solvent, polysorbate 80 or benzyl alcohol, used to assist in dissolving the drug [6–8].

Why does amiodarone cause thyroid level dysfunction?

However, amiodarone is associated with a number of side effects, including thyroid dysfunction (both hypo- and hyperthyroidism), which is due to amiodarone’s high iodine content and its direct toxic effect on the thyroid.

Is de Quervain’s thyroiditis hyperthyroidism?

This article will focus on subacute granulomatous thyroiditis, also known as subacute thyroiditis, painful thyroiditis, subacute nonsuppurative thyroiditis, giant cell thyroiditis, or de Quervain thyroiditis. It is an infrequent cause of hyperthyroidism.

What are the serious side effects of amiodarone?

Amiodarone should only be used if you have a life threatening arrhythmia or irregular heart rate. This medication has the risk of serious side effects. These include serious lung problems, liver problems, and a worsening of your irregular heart rate. These problems can be fatal.

Is amiodarone a vasopressor or vasodilator?

Objective: Amiodarone, a class III antiarrhythmic agent, is a potent coronary vasodilator.

Can you give amiodarone with low heart rate?

Intravenous amiodarone therapy should not be used in patients with bradycardia or heart block who do not have a pacemaker. Because phlebitis may occur, the drug should be given through a central venous line when possible.

What class of antiarrhythmic is amiodarone?

Amiodarone is a class III antiarrhythmic, based on the benzofuran structure used in atrial and ventricular fibrillation therapy 12. Amiodarone is a multichannel blocker affecting delayed rectifier IKr, sodium channel and L‐type calcium currents.

What is subclinical hypothyroidism in amiodarone?

In the SAFE-Trial subclinical hypothyroidism, defined as a TSH of 4.5–10 mU/l with normal thyroid hormone levels [Nademanee et al. 1986] was detected in 25.8% of patients taking amiodarone, while overt hypothyroidism (TSH > 10 mU/l) occurred in 5% [Batcher et al.

Is amiodarone an antiarrhythmic?

Amiodarone has widespread clinical applicability as an antiarrhythmic. It is probably the most effective agent at maintaining sinus rhythm in patients with both paroxysmal and persistent atrial fibrillation (AF) and with both preserved and impaired left ventricular systolic function [Singh, 2008; Vassallo and Trohman, 2007].

How many atoms of iodine are in amiodarone?

Amiodarone contains two iodine atoms. It is estimated that amiodarone metabolism in the liver releases approximately 3 mg of inorganic iodine into the systemic circulation per 100 mg of amiodarone ingested. The average iodine content in a typical American diet is approximately 0.3 mg/day.

How is the diagnosis of amiodarone induced thyrotoxicosis confirmed?

To confirm the diagnosis of amiodarone induced thyrotoxicosis, it is necessary to demonstrate a suppressed serum TSH associated with an increase in serum free T3 and free T4 levels in a patient treated with amiodarone ( NCBI – Amiodarone Induced Thyrotoxicosis )