Prescription Required 
Formulation : 
Description
Indications
Levothyroxine is prescribed for the treatment of hypothyroidism, a condition characterized by an underactive thyroid gland. The medication is designed to replace or supplement the body’s natural production of thyroid hormone, which is vital for regulating mental and physical activity. Hypothyroidism can occur naturally, or as a result of radiation/medication damage, or surgical removal of the thyroid gland. Adequate levels of thyroid hormone are essential for normal physical and mental development in children.
Uses and Dosage
Levothyroxine is available in both tablet and capsule form for oral consumption. It is usually taken once a day on an empty stomach, 30 minutes to 1 hour before breakfast. Take levothyroxine exactly as directed, without taking more or less than the prescribed amount, and do not take it more often than recommended by your doctor.
Capsules should be swallowed whole, without being chewed or crushed, and should not be removed from the packaging until ready to use.
Tablets should be taken with a full glass of water to prevent choking or gagging.
If you need to administer levothyroxine to an individual who is unable to swallow a tablet, crush the tablet and mix it with 1 to 2 teaspoons (5 to 10 mL) of water. The crushed tablet should only be mixed with water, not food or soybean infant formula. Administer the mixture by spoon or dropper immediately, without storing it for later use.
Your doctor will most likely begin you on a low dose of levothyroxine and gradually increase it.
While levothyroxine controls hypothyroidism, it does not cure it. It may take several weeks before you notice a change in your symptoms. Continue taking levothyroxine even if you feel well, and to not discontinue use without consulting your doctor.
Side Effects
Some side effects may occur that usually do not need medical attention:
- weight gain or loss
- headache
- vomiting
- diarrhea
- changes in appetite
- fever
- changes in menstrual cycle
- sensitivity to heat
- hair loss
- joint pain
- leg cramps
Inform your healthcare provider immediately if you experience any serious side effects:
- shortness of breath
- wheezing
- hives, itching, rash
- flushing
- stomach pain, nausea
- swelling of hands, feet, ankles, or lower legs
Caution
Before taking levothyroxine, inform your doctor or pharmacist if you have any allergies or allergic reactions to any inactive ingredients present in the medication. Speak with your pharmacist for more information on this.
Prior to using this medication, inform your doctor or pharmacist about your medical history, especially if you have an overactive thyroid gland (thyrotoxicosis), reduced adrenal gland function, heart disease, high blood pressure, or diabetes.
If you have diabetes, this medication may affect your blood sugar levels. Follow your doctor’s instructions and monitor your blood sugar levels regularly, sharing the results with your doctor. If you experience symptoms such as increased thirst/urination, shakiness, unusual sweating, dizziness, or hunger, inform your doctor immediately. Your doctor may need to adjust your diabetes medication, exercise regimen, or diet.
Children may be more sensitive to certain side effects of this medication, such as headache, hip/leg pain, and vision changes. Increased thyroid hormone levels may result in decreased bone growth/development and reduced adult height. Keep all medical appointments and follow-ups, so the doctor can monitor treatment.
Older adults may be more susceptible to the side effects of this medication, particularly fast/pounding/irregular heartbeat.
This medication may be used during pregnancy. Inform your doctor if you are pregnant, as the doctor may need to adjust your dosage.
Levothyroxine is excreted in breast milk, but it is unlikely to harm a nursing infant. Consult your doctor before breastfeeding.
Form and Strength
Synthroid is available in the following forms and strengths:
-
Synthroid tablet:
- 0.05mg
- 0.075mg
- 0.088mg
- 0.100mg
- 0.112mg
- 0.125mg
- 0.137mg
- 0.15mg
- 0.175mg
- 0.200mg
- 0.300mg
FAQ
Why can’t I drink coffee after taking Synthroid?
Even sips of coffee can affect Synthroid if the two aren’t spaced apart enough. In studies, coffee reduced the body’s absorption of thyroid medications by about 30%.
Does Synthroid cause weight gain?
In some cases, Synthroid may lead to weight gain. This is because the drug can increase your appetite, which may make you eat more food than usual.
Resources
- https://www.goodrx.com/conditions/hypothyroidism/8-things-that-can-mess-with-your-thyroid-medication
- https://www.medicalnewstoday.com/articles/synthroid#side-effects
- https://www.medbroadcast.com/drug/getdrug/synthroid
- https://www.webmd.com/drugs/2/drug-7033/synthroid-oral/details
- https://medlineplus.gov/druginfo/meds/a682461.html
- https://www.drugs.com/synthroid.html
