Thyroid Replacement Tx

OB/GYN News, June 15, 2001 by Sally Koch Kubetin

A sudden hike in cholesterol level in a patient on thyroid replacement therapy may be due to an interaction between thyroxine and iron that can lead to hypothyroidism, Dr. Douglas S. Paauw said at the annual meeting of the American College of Physicians-American Society of Internal Medicine.

Thyroid hormone also is likely to bind to cholestyramine, sucralfate, and antacids that contain magnesium and aluminum. Case reports have also described an increase in TSH levels among patients who have taken calcium supplementation along with their hormone therapy said Dr. Paauw of the University of Washington, Seattle.

Quinolones also tend to bind to antacids, iron, sucralfate, and older formulations of didanosine that had a built-in antacid. The solution: With both thyroid hormone and quinolones, Dr. Paauw recommended that patients take these drugs 2 hours before or 6 hours after the binding agent.