Oral Cholecystographic Agents and the Thyroid

Abstract

Oral cholecystographic agents (OCAs) are known to affect thyroid hormone metabolism by acting as potent inhibitors of type I and type II deiodinases, blocking the conversion of T(4) to T(3) and rT(3) to T(2). In addition, iodine released from the drug blocks thyroid gland secretion of thyroid hormone. These properties make OCAs a potentially useful drug therapy in patients with hyperthyroidism and other thyrotoxic disorders. Short-term treatment with OCAs rapidly reduces serum T(3) levels, with a lesser effect on T(4) levels. OCAs are not useful for long-term treatment, which is usually followed by exacerbation of hyperthyroidism with continued use. The lack of significant side effects makes these drugs an excellent short-term option in situations where a rapid clinical improvement is critical.

Amiodarone-Induced Thyrotoxicosis

“…However, mixed forms manifesting features of both type 1 and type 2 disease commonly are found (9). Although prospective data are scarce (10), type 1 disease is usually treated with antithyroid drugs and type 2 disease is usually treated with additional prednisone therapy and/or iopanoic acid (11). Some refractory cases even need thyroidectomy (12).…”

Thyroid Medications During Pregnancy

“…102,103 This rapid effect makes ipodate and iopanoic acid useful in quickly preparing patients for thyroid surgery or in the treatment of severe hyperthyroidism or thyroid storm. They have a rapid action and serum T 3 concentration falls to normal levels by 5 days.…”

“…They have a rapid action and serum T 3 concentration falls to normal levels by 5 days. 102,103 Long-term use of these agents may result in resistant hyperthyroidism and should therefore be avoided. 102 These agents are rarely used as longterm monotherapy for Graves' hyperthyroidism, as they do not provide as effective control as thionamides in this setting.…”

“…102,103 This rapid effect makes ipodate and iopanoic acid useful in quickly preparing patients for thyroid surgery or in the treatment of severe hyperthyroidism or thyroid storm. 102,103 Their short-term rapid effects make these agents effective during the hyperthyroid phase of subacute thyroiditis. They are usually used only for short-term therapy and have high relapse rates after their discontinuation.…”

Successful Treatment of Hyperthyroidism with Amiodarone in a Patient with Propylthiouracil-Induced Acute Hepatic Failure

“…The patient's parents denied ingestion of other drugs or alcohol. Laboratory tests demonstrated high levels of transaminases aspartate transferase (AST) 2157 U/L (normal values, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and alanine transferase (ALT) 3827 U/L (normal values, 7-30), elevated total bilirubin levels 20.4 mg% (normal values, 0-1), and low prothrombin levels (international normalized ratio [INR] 4) ( Table 1). Abdominal ultrasound was normal.…”