PURPOSE: Amiodarone hydrochloride is an iodine-rich drug effective in the 
control of various tachyarrhythmias. It is known to cause refractory to 
thyrotoxicosis, which usually does not respond to regular antithyroid drugs. 
Lithium bicarbonate is a medication used to treat psychiatric disorders; it also 
influences thyroid production and release of hormones. We tried it in 
combination with propylthiouracil (PTU) for the treatment of amiodarone-induced 
thyrotoxicosis.
PATIENTS AND METHODS: Twenty-one patients were studied. The first group (n = 5) 
was treated by amiodarone withdrawal only. The second group (n = 7) received PTU 
(300 to 600 mg), and the third (n = 9) PTU (300 mg) and lithium (900 to 1350 mg) 
daily. Patient selection was not randomized. The PTU + lithium group had more 
severe symptoms and signs of thyrotoxicosis, as well as thyroxine levels at 
least 50% above the upper limit of normal. They also had been on a longer course 
of amiodarone treatment (34.3 +/- 11.9 months) than the PTU-only (11.4 +/- 7.5) 
and the no-treatment (7.8 +/- 4.2) groups.
RESULTS: While there was no difference between the first two groups in time 
until recovery (10.6 +/- 4.0 versus 11.6 +/- 0.5 weeks, respectively), the group 
receiving lithium normalized their thyroid function tests in only 4.3 +/- 0.5 
weeks (P < 0.01 versus both other groups). T3 levels normalized even earlier-by 
3 weeks of lithium treatment. No adverse effects of lithium were encountered, 
and the medication was stopped 4 to 6 weeks after achieving a normal clinical 
and biochemical state.
CONCLUSIONS: We conclude that lithium is a useful and safe medication for 
treatment of iodine-induced thyrotoxicosis caused by amiodarone. We would 
reserve this treatment for severe cases only. Further studies are needed to find 
out whether in patients with this troublesome complication lithium therapy could 
permit continuation of amiodarone treatment.