Precautions and warnings

People with angina, heart failure, diabetes (both DM and diabetes insipidus), older adults, those with long-term hypothyroidism, adrenal insufficiency, or myxoedema should use caution. Do not use this medication for treating obesity or for weight loss. Be careful during pregnancy and breastfeeding.

Drug Interactions

Levothyroxine may not be absorbed well if you take it with iron, antacids, bile acid-binding drugs (like colestyramine), simethicone, calcium carbonate, sucralfate, or cation exchange resins. The level of active thyroid hormone (T3) in the blood may be lower if you use amiodarone or propranolol. The level of thyroxine (T4) in the blood may be lower if you take carbamazepine, phenytoin, phenobarbital, rifampicin, lithium, estrogen, or sertraline. Androgens may reduce the amount of protein that carries levothyroxine in the blood. Levothyroxine may change how much antidiabetic medication you need. Taking ketamine with levothyroxine can raise the risk of high blood pressure and a fast heartbeat. Drugs that raise metabolism (like epinephrine) can also increase your body's demand for thyroid hormone. Levothyroxine may also make the blood-thinning effect of warfarin stronger.

Contraindications

Untreated hyperthyroidism; uncorrected adrenal failure; recent MI.

Mode of actions

Levothyroxine sodium is a man-made version of thyroxine, a hormone that raises the body’s basic metabolic rate (BMR). It helps the body use and release stored glycogen and encourages the building of proteins. It also plays an important role in normal metabolism, growth, and development. These effects happen in the body’s cells through a substance called tri-iodothyronine, which is made from thyroxine.

Dosage & Administration

Adult: PO Hypothyroidism Inital: 50-100 mcg/day. Maintenance: 100-200 mcg/day. Severe and chronic hypothyroidism Initial: 12.5-25 mcg/day, increase gradually if needed.

TSH supression For thyrotropin-dependent well-differentiated thyroid cancer: Doses >2 mcg/kg/day may be used to achieve TSH target of

Pregnancy & Lactation

Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy and there is not enough evidence of risk in later trimesters.

Pack Size & Price