Association between N-desethylamiodarone/amiodarone ratio and amiodarone-induced thyroid dysfunction

Area of Science:

• Pharmacology
• Endocrinology
• Clinical Chemistry

Background:

• Amiodarone (AMD) is an effective antiarrhythmic drug, but its use is associated with thyroid dysfunction.
• N-desethylamiodarone (DEA) is the primary active metabolite of AMD.
• The relationship between AMD and DEA concentrations and thyroid hormone levels requires further investigation.

Purpose of the Study:

• To explore the association between serum amiodarone (AMD) and N-desethylamiodarone (DEA) concentrations and thyroid-related hormone levels.
• To determine if the DEA/AMD ratio can serve as a predictive marker for AMD-induced thyroid dysfunction.

Main Methods:

• Retrospective data mining of laboratory data from January 2012 to April 2016.
• Analysis of serum AMD and DEA concentrations and thyroid function tests (TSH, FT4, FT3) from 330 patients.
• Classification of patients into euthyroidism, hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, and subclinical hypothyroidism groups.

Main Results:

• A total of 1831 clinical laboratory data sets were analyzed.
• The mean DEA/AMD ratio was significantly higher in the hyperthyroidism group (0.95 ± 0.42) compared to the euthyroidism group (0.87 ± 0.28).
• The mean DEA/AMD ratio was significantly lower in the hypothyroidism group (0.77 ± 0.26) compared to the euthyroidism group (0.87 ± 0.28).
• Elevated TSH levels were associated with a lower DEA/AMD ratio, while suppressed TSH and elevated FT4 levels were associated with higher DEA/AMD ratios.

Conclusions:

• High and low DEA/AMD ratios are associated with amiodarone-induced hyperthyroidism and hypothyroidism, respectively.
• The DEA/AMD ratio may serve as a predictive marker for amiodarone-induced thyroid dysfunction.
• Monitoring the DEA/AMD ratio could aid in the early detection and management of thyroid abnormalities in patients treated with amiodarone.