[Amiodarone-associated thyroid dysfunction: prevalence and possibilities of correction]

Area of Science:

• Cardiology
• Endocrinology
• Pharmacology

Background:

• Amiodarone is a potent antiarrhythmic drug with known potential for thyroid dysfunction.
• Thyroid dysfunction, including hypothyroidism and thyrotoxicosis, can complicate amiodarone therapy.
• Understanding the management and impact of amiodarone-associated thyroid dysfunction is crucial for patient care.

Purpose of the Study:

• To investigate the incidence and clinical course of amiodarone-associated thyroid dysfunction.
• To evaluate the efficacy of managing thyroid dysfunction while continuing amiodarone therapy.
• To assess the impact of thyroid status correction on amiodarone's antiarrhythmic efficacy.

Main Methods:

• Prospective observation of patients receiving amiodarone over 1 year.
• Monitoring for development of hypothyroidism and thyrotoxicosis.
• Treatment strategies included L-thyroxine for hypothyroidism and anti-thyroid drugs/prednisolone for thyrotoxicosis.

Main Results:

• 25% of patients developed amiodarone-associated thyroid dysfunction (19.2% hypothyroidism, 5.8% thyrotoxicosis).
• Hypothyroidism did not impair amiodarone's efficacy; L-thyroxine therapy was effective.
• Thyrotoxicosis led to loss of amiodarone efficacy in all cases; treatment allowed continued amiodarone use in 87.5% of patients.

Conclusions:

• Amiodarone-induced hypothyroidism can be managed with L-thyroxine without compromising antiarrhythmic efficacy.
• Correction of amiodarone-associated thyrotoxicosis restores the drug's antiarrhythmic effectiveness.
• Continued amiodarone use is often feasible and necessary, even with thyroid dysfunction, due to life-saving indications.