potassium-perchlorate and Arrhythmias--Cardiac

Amiodarone can induce severe hyperthyroidism that justifies its withdrawal and the introduction of antithyroid drugs. Continuing amiodarone use, failure to control hyperthyroidism and poor clinical progress may require thyroidectomy. This study aimed to evaluate patients' post-operative development and mid-term outcome after thyroidectomy for amiodarone-associated thyrotoxicosis.. Prospective case series.. Tertiary care centre.. We prospectively collected cases of amiodarone-associated thyrotoxicosis requiring thyroidectomy due to failure of antithyroid treatment, despite amiodarone discontinuation. Post-thyroidectomy complications were compared immediately, 30 days and one year post-operatively, and also for scheduled versus emergency surgery cases.. Of 11 total cases, nine scheduled thyroidectomy cases had no morbidity after elective surgery. Two cases required emergency surgery for multiple organ failure and cardiac problems. Immediate post-operative complications (mostly haemodynamic) occurred in both cases (emergency vs routine surgery, p = 0.018).. In such cases, pre-operative medical treatment is vital to limit peri- and post-operative complications, but surgery should not be delayed if the haemodynamic status deteriorates. Surgery, with careful anaesthesia, is the cornerstone of the treatment.

Topics: Adult; Aged; Aged, 80 and over; Amiodarone; Anti-Arrhythmia Agents; Antithyroid Agents; Arrhythmias, Cardiac; Drug Therapy, Combination; Female; Glucocorticoids; Humans; Male; Methylprednisolone; Middle Aged; Perchlorates; Postoperative Complications; Potassium Compounds; Preoperative Care; Prospective Studies; Severity of Illness Index; Thyroid Hormones; Thyroidectomy; Thyrotoxicosis; Time Factors; Treatment Outcome

To exploit the antiarrhythmic effect of amiodarone when patients develop the side effect of thyrotoxicosis three patients with hyperthyroidism induced by amiodarone were given simultaneously 1 g potassium perchlorate a day for 40 days and a starting dose of 40 mg methimazole a day while they continued to take amiodarone. As hyperthyroidism might have recurred after potassium perchlorate treatment was stopped the dose of methimazole was not reduced until biochemical hypothyroidism (raised thyroid stimulating hormone concentrations) was achieved. The patients became euthyroid (free triiodothyronine concentration returned to normal values) in two to five weeks and hypothyroid in 10 to 14 weeks. One patient became euthyroid while taking 5 mg methimazole a day and 600 mg amiodarone weekly; the two others required substitution treatment with thyroxine sodium while taking 5 mg methimazole or 50 mg propylthiouracil (because of an allergic reaction to methimazole) and 2100 or 1400 mg amiodarone weekly. Hyperthyroidism induced by amiodarone may be treated with potassium perchlorate and methimazole given simultaneously while treatment with amiodarone is continued.

Topics: Aged; Amiodarone; Arrhythmias, Cardiac; Drug Evaluation; Drug Therapy, Combination; Humans; Hyperthyroidism; Methimazole; Middle Aged; Perchlorates; Potassium; Potassium Compounds; Thyroid Gland