Dextrothyroxine sodium Disease Interactions

The use of dextrothyroxine sodium is contraindicated in euthyroid patients with one or more of the following conditions: hypertension (other than mild, labile systolic hypertension); known or suspected organic heart disease, especially coronary heart disease; a history of myocardial infarction; cardiac arrhythmias or a demonstrated propensity for arrhythmias; tachycardia; rheumatic heart disease; a history of congestive heart failure; or decompensated or borderline compensated cardiac status. Dextrothyroxine sodium may cause severe cardiotoxicity related to its thyroid hormone activity, occasionally even in patients without apparent underlying cardiac abnormalities. In a large study involving men who had had a myocardial infarction, treatment with dextrothyroxine sodium was associated with a trend toward increased mortality relative to placebo. Therapy with dextrothyroxine sodium should be considered and administered cautiously in patients with risk factors for coronary artery disease, including obesity, a history of smoking, and/or a family history of premature coronary disease.

The use of dextrothyroxine sodium is contraindicated in patients with hyperthyroidism or a history of iodism. Dextrothyroxine sodium possesses thyroid hormone activity and may exacerbate these conditions.

The use of dextrothyroxine sodium is contraindicated in patients with advanced liver disease. The site of action of dextrothyroxine sodium is in the liver, where it stimulates the catabolism and excretion of cholesterol and its degradation products via the biliary route into the feces. Patients with severe hepatic impairment may not tolerate these effects.

The use of dextrothyroxine sodium is contraindicated in patients with advanced kidney disease. The clearance of dextrothyroxine sodium may be reduced when renal function is impaired. Therapy with dextrothyroxine sodium should be administered cautiously in patients with mild to moderate degrees of renal impairment. A more gradual dosage titration may be required to prevent toxicity.

Dextrothyroxine sodium can elevate serum glucose levels and decrease glucose tolerance in diabetic patients. Patients with diabetes mellitus should be monitored more closely during dextrothyroxine therapy, and adjustments made accordingly in their antidiabetic regimen. If an increase in insulin and/or oral hypoglycemic dosage is required, clinicians should be aware that readjustments may likely be necessary whenever dextrothyroxine therapy is withdrawn.