The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drugs’ FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:
If you take these drugs with thyroid, risk of heart complications increases: ADRENALIN, amitriptyline, bee-sting kits, ELAVIL, epinephrine, imipramine, KETALAR, ketamine, LUDIOMIL, maprotiline.
If you take anticoagulants or drugs for diabetes, extra monitoring may be required, especially if you stop, start, or change doses of either thyroid or: acarbose, acetohexamide, ACTOS, AMARYL, AVANDIA, chlorpropamide, COUMADIN, DIABINESE, DIAMICRON, DYMELOR, glicaside, glimepiride, glipizide, GLUCOPHAGE, GLUCOTROL, GLUCOVANCE, glyburide, GLYNASE, insulin, metformin, nateglinide, ORINASE, pioglitazone, PRANDIN, PRECOSE, repalginide, rosiglitazone, STARLIX, tolazamide, tolbutamide, TOLINASE, warfarin.
Many other drugs can interact with thyroid products and may require adjustments in doses. These include: carbamazepine, digoxin, DILANTIN, LANOXIN, LUMINAL, oral contraceptives, oral estrogens, phenobarbital, phenytoin, PREMARIN, PREMPRO, RIFADIN, rifampin, rifapentine, RIMACTANE, ROFACT, TEGRETOL.
Some drugs are more apt to interact with thyroid in high doses. Of particular note are: DECADRON (dexamethasone) over 4 milligrams per day, Inderal (propranolol) over 160 milligrams per day, salicylates, such as aspirin or sodium salicyclate, over 2 grams (2,000 milligrams) per day.
The following drugs may prevent absorption of thyroid drugs. If you take these, take four to five hours apart from thyroid: ALUDROX, aluminum, antacids, calcium carbonate, CARAFATE, cholestyramine, COLESTID, colestipol, FEOSOL, ferrous sulfate, iron preparations, KAYEXALATE, MAALOX, magnesium, MYLICON, QUESTRAN, simethicone, sucralfate, TUMS.
The following proton pump inhibitor drugs used to treat heart burn and other stomach-acid related disorders may decrease levothyroxine effectiveness: ACIPHEX, DEXILANT, dexlansoprazole, esomeprazole, lansoprazole, NEXIUM, NEXIUM 24HR, omeprazole, pantoprazole, PREVACID, PREVACID 24HR, PRILOSEC, PRILOSEC OTC, PROTONIX, rabeprazole, YSOPRALA, ZEGERID
If you take these drugs, it could affect results of thyroid monitoring tests: amiodarone, carbamazepine, CORDARONE, iodine, sertraline, TEGRETOL, ZOLOFT.