Remission after potassium iodide therapy in patients with Graves' hyperthyroidism exhibiting thionamide-associated side effects.

Abstract

CONTEXT:

Thionamides have various side effects.

OBJECTIVE:

The effectiveness of potassium iodide (KI) was evaluated in hyperthyroid patients who experienced side effects to thionamides.

DESIGN AND SETTING:

An observational study was conducted at an academic medical center.

PATIENTS:

Among 1388 patients with Graves' hyperthyroidism treated with thionamides, 204 (14.7%) exhibited side effects, and 44 were treated with KI and followed for 17.6 (median; range, 8.6-28.4) years.

MAIN OUTCOME MEASURES:

The primary endpoint was the initial response to KI, and the secondary endpoint was the long-term prognosis.

RESULTS:

The conditions of 29 (65.9%) of the 44 patients were well controlled with KI alone (10-400 mg/d) (A group), and 17 (38.6%) patients went into remission after 7.4 (1.9-23.0) years. The conditions of 15 (34.1%) patients were not controlled with KI alone (B group), even at a high dose (100-750 mg/d), but seven patients (15.9%) were controlled with a combination of KI and low-dose thionamides, resulting in remission after 7.2 (2.8-10.8) years. The initial parameters did not predict the response to KI or long-term prognosis. However, remission occurred in 70.8% of the patients treated with less than 200 mg of KI, compared with 35.0% of the patients who required 200 mg or more of KI (P < .05).

CONCLUSIONS:

Among hyperthyroid patients with thionamide-associated side effects, KI therapy was effective in two-thirds of cases, and about 40% of the patients experienced remission after KI therapy alone. The chance of remission was small among the patients refractory to KI.

• Authors: Ken Okamura, Kaori Sato, Megumi Fujikawa, Sachiko Bandai, Hiroshi Ikenoue, Takanari Kitazono
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 99 Issue 11 Pg. 3995-4002 (Nov 2014) ISSN: 1945-7197 [Electronic] United States
• PMID: 25144628 (Publication Type: Journal Article)

Chemical References

• Antithyroid Agents
• Potassium Iodide
• Methimazole
• Propylthiouracil

Topics

• Adolescent
• Adult
• Aged
• Antithyroid Agents (adverse effects, therapeutic use)
• Drug Administration Schedule
• Female
• Graves Disease (drug therapy)
• Humans
• Male
• Methimazole (adverse effects, therapeutic use)
• Middle Aged
• Potassium Iodide (therapeutic use)
• Propylthiouracil (adverse effects, therapeutic use)
• Remission Induction (methods)
• Retreatment
• Treatment Outcome
• Young Adult