Generic name: Levothyroxine Injection Solution [ lee-voe-thye-ROKS-een ]
Drug class: Thyroid drugs
Medically reviewed by Drugs.com. Last updated on Jun 26, 2023.
- Do not use levothyroxine injection solution to treat obesity or for weight loss. Very bad and sometimes deadly side effects may happen with levothyroxine injection solution if it is taken in large doses or with other drugs for weight loss. Talk with the doctor.
Uses of Levothyroxine Injection Solution:
- It is used to add thyroid hormone to the body.
- It is used to manage thyroid cancer.
- It may be given to you for other reasons. Talk with the doctor.
What do I need to tell my doctor BEFORE I take Levothyroxine Injection Solution?
- If you have an allergy to levothyroxine or any other part of levothyroxine injection solution.
- If you are allergic to levothyroxine injection solution; any part of levothyroxine injection solution; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
- If you have any of these health problems: Overactive thyroid gland or weak adrenal gland.
This is not a list of all drugs or health problems that interact with levothyroxine injection solution.
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take levothyroxine injection solution with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
What are some things I need to know or do while I take Levothyroxine Injection Solution?
For all patients taking levothyroxine injection solution:
- Tell all of your health care providers that you take levothyroxine injection solution. This includes your doctors, nurses, pharmacists, and dentists.
- Do not run out of levothyroxine injection solution.
- It may take several weeks to see the full effects.
- If you have high blood sugar (diabetes), levothyroxine injection solution may sometimes raise blood sugar. Talk with your doctor about how to keep your blood sugar under control.
- Check your blood sugar as you have been told by your doctor.
- Have blood work checked as you have been told by the doctor. Talk with the doctor.
- This medicine may cause weak bones (osteoporosis) with doses that are too high. The risk may be higher in women who have been through menopause. Talk with your doctor to see if you have a higher risk of weak bones or if you have any questions.
- This medicine may affect fertility. Fertility problems may lead to not being able to get pregnant or father a child.
- If you are 65 or older, use levothyroxine injection solution with care. You could have more side effects.
- Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.
- If giving levothyroxine injection solution to your child and your child's weight changes, talk with the doctor. The dose of levothyroxine injection solution may need to be changed.
- This medicine may affect growth in children and teens in some cases. They may need regular growth checks. Talk with the doctor.
How is this medicine (Levothyroxine Injection Solution) best taken?
Use levothyroxine injection solution as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- It is given as a shot into a vein.
What do I do if I miss a dose?
- Call your doctor to find out what to do.
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of high blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
- Chest pain or pressure.
- Fast or abnormal heartbeat.
- Shortness of breath, a big weight gain, or swelling in the arms or legs.
- Feeling tired or weak.
- Feeling more or less hungry.
- A change in weight without trying.
- Stomach cramps.
- Throwing up.
- Feeling irritable.
- Feeling nervous and excitable.
- Emotional ups and downs.
- Trouble sleeping.
- Bothered by heat.
- Sweating a lot.
- Muscle cramps.
- Muscle weakness.
- Bone pain.
- Period (menstrual) changes.
What are some other side effects of Levothyroxine Injection Solution?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Hair loss may happen in some people in the first few months of using levothyroxine injection solution. This most often goes back to normal.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
If OVERDOSE is suspected:
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
How do I store and/or throw out Levothyroxine Injection Solution?
- If you need to store levothyroxine injection solution at home, talk with your doctor, nurse, or pharmacist about how to store it.
Consumer Information Use and Disclaimer
- If your symptoms or health problems do not get better or if they become worse, call your doctor.
- Do not share your drugs with others and do not take anyone else's drugs.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
- Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about levothyroxine injection solution, please talk with your doctor, nurse, pharmacist, or other health care provider.
- If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
Frequently asked questions
- Does levothyroxine cause weight gain or loss?
- What can I eat for breakfast after taking levothyroxine?
- Can I take other medications with levothyroxine?
- Does levothyroxine cause hair loss?
- How long after taking levothyroxine can you drink milk?
- How long does levothyroxine stay in your system?
- How soon after taking levothyroxine can I take omeprazole?
- What happens if you stop taking levothyroxine?
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- Drug class: thyroid drugs
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