Levothyroxine Side Effects and Warnings

What are the precautions when taking this medicine?

• There are different brands of this medicine. One brand cannot safely be exchanged for another. Any change must be directed by healthcare provider.

• If you are 65 or older, use this medicine with caution. You could have more side effects.

• If you have heart disease, talk with healthcare provider.

• If you have osteoporosis, talk with healthcare provider.

• If you are allergic to tartrazine, talk with healthcare provider. Some products contain tartrazine.

• Check medicines with healthcare provider. This medicine may not mix well with other medicines.

• Do not take iron products, aluminum- and magnesium-containing antacids, calcium carbonate, simethicone, sucralfate, Kayexalate®, colestipol, or cholestyramine within 4 hours of this medicine.

• Tell healthcare provider if you are pregnant or plan on getting pregnant.

What are some possible side effects of this medicine?

• Unexplained change in appetite.

• Unexplained change in weight.

• Nervous and excitable.

• Inability to sleep.

• Shakiness.

• Sensitive to heat.

• Excessive sweating.

• Headache.

• Nausea or vomiting. Small frequent meals, frequent mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.

• Diarrhea.

• Irritable.

• Leg cramps.

• Weakened bones with long-term use.

Reasons to call healthcare provider immediately

• If you suspect an overdose, call your local poison control center or emergency department immediately.

• Signs of a life-threatening reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; fits; or swelling of face, lips, tongue, or throat.

• Chest pain or pressure or fast heartbeat.

• Difficulty breathing.

• Very nervous and excitable.

• Significant weight gain.

• Significant weight loss.

• Any rash.

• No improvement in condition or feeling worse.