Endocrine Abstracts

We would like to point out that the incidence of amiodarone induced thyreotoxicosis is considerable. It is essential that both cardiologists and endocrinologists tightly cooperate when treating patients with amiodarone.

Methods: We analysed retrospectively data of 150 pacients (100 male and 50 female), whith average age 63.97±12.13 years, treated with amiodarone, followed-up on arythmologic outpatient clinic from 1.1.2005 till 31.12.2006. All of the patients had TSH a fT4 examined on regular basis.

Results: The average value of TSH of all the patients during the 24 months of follow-up was 4.24±6.6 mIU/l, the average value of fT4 was 22.12±18.38 pmol/l.

Amiodarone induced hypothyroidism was confirmed in 9 (6%) pacients (median TSH:15.43 mUI/l a median fT4 12.2 pmol/l). The average time of treatment by amiodarone in this group was 22 months.

Amiodarone induced thyreotoxicosis was confirmed in 12 (8%) pacients (median fT4 33.6 pmol/l and median TSH 0.015 mIU/l). The average time of treatment by amiodarone in this group was 30 months.

We include two interesting case reports of patients with implanted ICD. The first case presented with oligosymptomatic form of amiodarone induced thyreothoxicosis. The second case presented with thyreotoxic crisis requiring acute total thyreoidectomy.

Conclusions: Despite the new antiarhytmic drugs that have been evolved lately, amiodarone is still a potent antiarhytmic which is in some cases a medicine of choice. One of the feared side effects is amiodarone induced thyreotoxicosis, which is a serious (potentially fatal) condition that requires prompt diagnosis and treatment. Regular checks of TSH and fT4 in pacients using amiodarone are essential.