Levoxyl, a synthetic thyroid hormone, is a prescription medication used as a replacement or supplemental therapy in hypothyroidism (underactive thyroid). This medication is used to treat a variety of thyroid problems including nodules and goiters, as well as some types of thyroid cancer.
This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.
Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Many medicines affect the absorption and metabolism of Levoxyl and may change the way your body responds to Levoxyl. Additionally, Levoxyl has effects on the way your body responds to other medicines. The following medicines may interact with Levoxyl:
- amphetamines
- anticoagulants (‘blood thinners’) such as warfarin (Coumadin)
- antidepressants or anti-anxiety agents
- arthritis medicine
- aspirin
- beta-blockers such as metoprolol (Lopressor, Toprol), propranolol (Inderal) or timolol (Blocadren, Timoptic)
- cancer chemotherapy agents
- diabetes medications (insulin and tablets)
- digoxin (Lanoxin)
- estrogens
- methadone
- oral contraceptives
- phenytoin (Dilantin)
- steroids
- theophylline (TheoDur)
- vitamins
- antacids
- cholestyramine (Questran)
- colestipol (Colestid)
- iron
- orlistat (Alli, Xenical)
- simethicone (Phazyme, Gas X)
- sodium polystrene sulfonate (Kayexalate)
- sucralfate (Carafate)
Tell your doctor about any side effect that is bothersome or does not go away.
This is not a complete list of Levoxyl drug interactions. Ask your doctor or pharmacist for more information.
WARNING: Thyroid hormones, including LEVOXYL, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects.
Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Levoxyl there are no specific foods that you must exclude from your diet when receiving Levoxyl.
Tell your doctor if you are pregnant or plan to become pregnant.
Studies in women taking Levoxyl during pregnancy have shown it is safe for use during pregnancy. It does not appear to cause harm to the unborn baby. In fact, it is important to treat hypothyroidism (underactive thyroid) during pregnancy, as undertreatment can be dangerous.
Tell your doctor right away if you become pregnant while taking Levoxyl. Pregnant women often require higher doses of Levoxyl.
Levoxyl (generic: levothyroxine) is a prescription medication used to treat underactive thyroid (hypothyroidism) and other thyroid problems. Levoxyl is a synthetic thyroid hormone, which replaces the body’s reduced levels of natural thyroid hormone.
This medication comes in tablet form and is taken once in the morning on an empty stomach, with a glass of water.
Common side effects of Levoxyl include tremors, change in appetite, and irregular heartbeats.
Dosing of Levoxyl must be individualized. Your doctor will determine the best Levoxyl dose for you, which will likely be carefully and slowly adjusted. Regular blood tests will be required to monitor your progress. Follow the directions on your prescription label carefully. Do not take more or less than prescribed. It may take several weeks before you begin to notice a change in your symptoms. Do not stop taking Levoxyl without talking to your doctor.
If you take too much Levoxyl, call your local Poison Control Center or seek emergency medical attention right away.
Too much Levoxyl can cause symptoms of hyperthyroidism, a condition in which you have too much thyroid hormone. If you experience the following symptoms, call your doctor right away as your dosage may need to be reduced:
- rapid or irregular heartbeat or pulse
- heart palpitations
- chest pain
- difficulty breathing
- leg cramps
- headache
- nervousness
- irritability
- sleeplessness
- tremors
- change in appetite
- weight gain or loss
- vomiting
- diarrhea
- excessive sweating
- heat intolerance
- fever
- changes in menstrual periods
- hives or skin rash
- any other unusual medical event
Levoxyl can cause allergic reactions. Symptoms include:
- wheezing
- difficulty breathing
- hives
- itching
- swelling of lips, mouth, throat
Call your doctor right away if you experience symptoms of allergic reaction.
This is not a complete list of Levoxyl side effects. Ask your doctor or pharmacist for more information.
Levoxyl is a tablet that is taken by mouth, usually once a day. It should be taken with a full glass of water. Take Levoxyl in the morning on an empty stomach, at least one-half hour to one hour before eating any food. Iron and calcium supplements and antacids can decrease the absorption of Levoxyl tablets. Take these products at least 4 hours before or 4 hours after you take Levoxyl.
If needed, Levoxyl tablets can be crushed and mixed in 1 to 2 teaspoons of plain water. This mixture must be taken right away.
If you forget a dose of Levoxyl, take the missed dose as soon as you remember it. If it is almost time for your next dose, skip the missed dose. Do not take a double dose of this medication.
Store Levoxyl tablets away from heat, moisture, and light.
Keep this and all medicines out of the reach of children.
Before taking Levoxyl tell your doctor:
- if you are allergic to Levoxyl or any foods or medicines
- if you are pregnant or intend to become pregnant, or if you are breastfeeding
- if you have heart disease, diabetes, clotting disorders, and adrenal or pituitary gland problems. Your dose of medications used to control these other conditions may need to be adjusted while you are taking Levoxyl. If you have diabetes, monitor your blood and/or urinary glucose levels as directed by your doctor and tell your doctor right away if there are any changes. If you are taking anticoagulants (blood thinners), your clotting status should be checked frequently.
Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.
You should not take Levoxyl if you:
- are allergic to any ingredient in the medication
- have hyperthyroidism (overactive thyroid)
- have a low TSH
- have untreated adrenal insufficiency
- have had a heart attack
Use Levoxyl only as prescribed by your physician. Do not discontinue or change the amount you take or how often you take it, unless directed to do so by your physician.
It may take several weeks before you notice an improvement in your symptoms.
Tell your doctor if you become pregnant while taking Levoxyl. It is likely that your dose of Levoxyl will need to be increased while you are pregnant.
Notify your doctor or dentist that you are taking this medicine prior to any surgery.
Partial hair loss may occur rarely during the first few months of Levoxyl therapy, but this is usually temporary.
Levoxyl should not be used as a weight loss medication in people without hypothyroidism.
Iron and calcium supplements and antacids can decrease the absorption of Levoxyl. Therefore, Levoxyl should not be administered within 4 hrs of these products.
Levoxyl may increase your risk of developing osteoporosis, especially if your Levoxyl dose is too high.
Tell your doctor if you are breastfeeding or plan to breastfeed. Small amounts of Levoxyl are excreted in human breast milk, just as natural thyroid hormone passes through breast milk. However, women who don’t have enough thyroid hormone may not be capable of lactation (secretion or formation of milk).
Active ingredient: levothyroxine sodium
Inactive ingredients: microcrystalline cellulose, croscarmellose sodium, magnesium stearate
In addition to the inactive ingredients listed above, each tablet (except the 50 mcg tablet) has additives for color. They are as follows:
25 mcg: FD&C Yellow No. 6
75 mcg: FD&C Blue No. 1, D&C Red No. 30
88 mcg: FD&C Yellow No. 6, FD&C Blue No. 1, D&C Yellow No. 10
100 mcg: FD&C Yellow No. 6, D&C Yellow No. 10
112 mcg: FD&C Yellow No. 6, FD&C Red No. D&C Red No. 30
125 mcg: FD&C Red No. 40, D&C Yellow No. 10
137 mcg: FD&C Blue No. 1
150 mcg: FD&C Blue No. 1, D&C Red No. 30
175 mcg: FD&C Blue No. 1, D&C Yellow No. 10
200 mcg: D&C Red No. 30, D&C Yellow No. 10