Table 2.

Main drugs potentially affecting thyroid function or thyroid hormone levels in patients with congenital hypothyroidism.

Drugs	More frequent use in children	Effects
Iron	Anaemia	Inhibition of l-T4 absorption
Calcium	Hypocalcaemia	Inhibition of l-T4 absorption
Aluminum/magnesium hydroxide	Gastro-esophageal reflux (antiacid)	Inhibition of l-T4 absorption
Sucralfate	Gastro-esophageal reflux (antiacid), gastritis, ulcers	Inhibition of l-T4 absorption
Colestyramine	Chronic cholestasis/inherited hyperlipidemia	Inhibition of l-T4 absorption
Colestipol	Chronic cholestasis/inherited hyperlipidemia	Inhibition of l-T4 absorption
Carbemazepine/Oxcarbemazepine	Seizures, mood disorders	TSH suppression; Increased hepatic metabolism
Glucocorticoids	Acute respiratory conditions as asthma and croups, inflammatory bowel diseases, nephrotic syndrome, etc	TSH suppression; inhibition of 5’ deiodinase; decreased thyroxine binding globulin levels
Nonsteroidal anti-inflammatory medications	Fever, musculoskeletal pain	Displacement from thyroxine binding globulin (laboratory artifact)
Phenytoin	Seizures	Increased hepatic metabolism; displacement from thyroxine binding globulin (laboratory artifact)
Phenobarbital	Seizures	Increased hepatic metabolism
Lithium	Acute mania and bipolar disorder	Inhibition of T4/T3 secretion
Dopamine agonists	Hyperprolactinemia	TSH suppression
Propranolol	Cardiac dysrhythmias	Inhibition of 5’ deiodinase
Rifampicin	Treatment of several types of bacterial infections	Increased hepatic metabolism
Furosemide	Renal, cardiac and peripheral oedema, ascites, hypertension)	Displacement from thyroxine binding globulin (laboratory artifact)
Iodide	Drugs containing iodide	Inhibition of 5’ deiodinase
Amiodarone	Cardiac arrhythmias	Inhibition of 5’ deiodinase, Thyroiditis
Nicotinic acid	Paediatric lipid disorders?	Decreased thyroxine binding globulin levels
Methadone	Life-Limiting Illness?	Increased thyroxine binding globulin levels