What is this medicine?
LEVOTHYROXINE (lee voe thye ROX een) is a thyroid hormone. This medicine can improve symptoms of thyroid deficiency such as slow speech, lack of energy, weight gain, hair loss, dry skin, and feeling cold. It also helps to treat goiter (an enlarged thyroid gland). It is also used to treat some kinds of thyroid cancer along with surgery and other medicines.
This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.
COMMON BRAND NAME(S): Estre, Euthyrox, Levo-T, Levothroid, Levoxyl, Synthroid, Thyro-Tabs, Unithroid
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
- Addison's disease or other adrenal gland problem
- bone problems
- dieting or on a weight loss program
- fertility problems
- heart disease
- pituitary gland problem
- take medicines that treat or prevent blood clots
- an unusual or allergic reaction to levothyroxine, thyroid hormones, other medicines, foods, dyes, or preservatives
- pregnant or trying to get pregnant
How should I use this medicine?
Take this medicine by mouth with plenty of water. It is best to take on an empty stomach, at least 30 minutes before or 2 hours after food. Follow the directions on the prescription label. Take at the same time each day. Do not take your medicine more often than directed.
Contact your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for children and infants as young as a few days of age for selected conditions, precautions do apply. For infants, you may crush the tablet and place in a small amount of (5-10 ml or 1 to 2 teaspoonfuls) of water, breast milk, or non-soy based infant formula. Do not mix with soy-based infant formula. Give as directed.
Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
What may interact with this medicine?
- 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
This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.
What should I watch for while using this medicine?
Be sure to take this medicine with plenty of fluids. Some tablets may cause choking, gagging, or difficulty swallowing from the tablet getting stuck in your throat. Most of these problems disappear if the medicine is taken with the right amount of water or other fluids.
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.
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.
What side effects may I notice from receiving this medicine?
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):
- changes in appetite
- weight loss
This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Where should I keep my medicine?
Keep out of the reach of children.
Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light and moisture. Keep container tightly closed. Throw away any unused medicine after the expiration date.
NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.