Levothyroxine / Liothyronine Side Effects
What should I watch for?
Do not switch brands of this medicine unless your health care professional agrees with the change. Ask questions if you are uncertain.
You will need regular exams and occasional blood tests to check the response to treatment. If you are receiving this medicine for an underactive thyroid, it may be several weeks before you notice an improvement. Check with your doctor or health care professional if your symptoms do not improve.
It may be necessary for you to take this medicine for the rest of your life. Do not stop using this medicine unless your doctor or health care professional advises you to.
This medicine can affect blood sugar levels. If you have diabetes, check your blood sugar as directed.
Some brands of this medicine may have a strong odor. This does not mean that the drug is spoiled.
You may lose some of your hair when you first start treatment. With time, this usually corrects itself.
If you are going to have surgery, tell your doctor or health care professional that you are taking this medicine.
Side Effects to watch for
Side effects that you should report to your doctor or health care professional as soon as possible:
- allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
- breathing problems
- changes in menstrual periods
- chest pain
- excessive sweating or intolerance to heat
- fast or irregular heartbeat
- leg cramps
- swelling of ankles, feet, or legs
- trouble sleeping
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
What may interact with this drug?
- anti-thyroid medicines
- calcium supplements
- certain medicines for depression
- certain medicines to treat cancer
- female hormones, like estrogens or progestins and birth control pills, patches, rings, or injections
- iron supplements
- liquid nutrition products like Ensure
- medicines for colds and breathing difficulties
- medicines for diabetes
- medicines or dietary supplements for weight loss
- phenobarbital or other barbiturates
- soy isoflavones
- steroid medicines like prednisone or cortisone