Levothyroxine - Benefits, dosage and side effects

Levothyroxine is a drug used to treat hypothyroidism, which is a condition in which thyroid hormone levels are low. In addition, this drug is also used in the treatment of myxedema coma. This medicine should only be used under a doctor's prescription.

Thyroid hormone deficiency can cause metabolic disorders, resulting in complaints, such as fatigue, constipation, dry skin, or forgetfulness.

Levothyroxine which is an artificial thyroid hormone will replace or increase levels of thyroid hormone that is lacking. That way, thyroid hormone levels can return to balance, and symptoms or complaints can subside.

Levothyroxine trademarks: Euthyrox, Levothyroxine Sodium, Tiavell, Thyrax

What is Levothyroxine

groupPrescription drugs
CategoryThyroid hormone
BenefitTreating hypothyroidism
Consumed byMature
Levothyroxine for pregnant and lactating womenCategory A:Controlled studies in pregnant women have not shown any risk to the fetus, and it is unlikely that harm to the fetus is possible.

Levothyroxine can be absorbed into breast milk. If you are breastfeeding, do not use this medicine without consulting your doctor first.

Drug formTablets, injections

 Precautions Before Using Levothyroxine

There are several things you should pay attention to before using levothyroxine, including:

  • Tell your doctor about your history of allergies. Levothyroxine should not be given to patients who are allergic to this drug.
  • Tell your doctor if you have adrenal insufficiency, thyrotoxicosis, thyroid nodules, heart disease, heart attack, diabetes, porphyria, osteoporosis, blood clotting disorders, kidney disease, obesity, liver disease, or swallowing disorders.
  • Tell your doctor if you have or have recently had radiotherapy
  • Tell your doctor if you are pregnant, breastfeeding, or planning a pregnancy.
  • Tell your doctor if you are taking certain medications, supplements, or herbal products.
  • See your doctor right away if you experience a drug allergic reaction, overdose, or serious side effect after using levothyroxine.

Levothyroxine Dosage and Directions

Levothyroxine is available in injectable and tablet form. The following is the dose of levothyroxine based on the patient's age, form of drug, and the condition to be treated:

Shape: Tablet

Condition: Hypothyroidism

  • Mature: Initial dose, 50–100 mcg/day. The dose can be increased by 25–50 mcg after 3–4 weeks according to the response and condition of the patient until the amount of thyroid hormone is normal. The maintenance dose is 100–200 mcg per day.
  • Newborn baby: The initial dose is 10-15 mcg/kg body weight per day. The dose can be adjusted every 4–6 weeks.
  • Newborns with thyroid hormone levels <5 mcg/dl: The initial dose is 50 mcg/kg body weight per day.
  • Infants aged 0–3 months: 10-15 mcg/kg body weight per day.
  • Babies aged 3–6 months: 8–10 mcg/kg body weight per day.
  • Infants aged 6–12 months: 6–8 mcg/kg body weight per day.
  • Children aged 1–5 years: 5–6 mcg/kg body weight per day.
  • Children aged 6–12 years: 4-5 mcg/kg body weight per day.
  • child age >12 years old: 2–3 mcg/kg body weight per day.
  • Adolescents who have entered puberty: Dosage follows the adult dose.

Condition: TSH suppressor (thyroid stimulating hormone)

  • Mature: Dosage of 2 mcg/kg body weight per day, given once daily as a single dose to suppress TSH in thyroid cancer or goiter.

Shape: Intravenous (IV) injection

Condition: Myxedema coma

  • Mature: Initial dose 200–500 mcg. On the next day the drug can be given as much as 100-300 mcg if needed. The dose can be reduced according to the patient's response and condition.
  • seniors: The dose will be adjusted by the doctor according to the patient's condition.

How to Use Levothyroxine Correctly

Always follow your doctor's advice and read the instructions on the medicine package before using levothyroxine tablets. Levothyroxine injectable form will be given by a doctor or medical personnel under the supervision of a doctor according to the patient's condition and response.

Take levothyroxine tablets on an empty stomach, for example 30–60 minutes before breakfast. Swallow the tablet whole with the help of a full glass of water. Take the medicine at the same time every day.

If you forget to take levothyroxine tablets, take them immediately if the distance to the next consumption schedule is not too close. If it is close, ignore it and do not double the dose.

Tell your doctor if you frequently forget to take levothyroxine. Take levothyroxine regularly for maximum treatment results. Do not stop using the drug without consulting your doctor first.

During treatment with levothyroxine, you will need to have your thyroid hormone levels checked regularly. Follow the control schedule given by the doctor.

Store levothyroxine in a dry place, at room temperature, and away from direct sunlight. Keep this medicine out of reach of children.

Levothyroxine Interactions with Other Drugs

Taking levothyroxine with other drugs can cause several drug interactions, such as:

  • Decreased absorption of levothyroxine when used with iron, antacids, bile acids, cholestyramine, simeticone, calcium carbonate, or sucralfate
  • Decreased blood levels of the hormone tri-iodothyronine (T3) when used with amiodarone or propranolol
  • Decreased blood levels of levothyroxine when used with carbamazepine, phenytoin, phenobarbital, rifampicin, lithium, estrogen, androgen hormones, or sertraline
  • Effect on the effectiveness of antidiabetic drugs
  • Increased risk of developing hypertension or tachycardia when used with ketamine
  • Increased risk of side effects, such as high blood pressure, palpitations, or chest pain when used with epinephrine
  • Increased risk of bleeding if used with warfarin

Levothyroxine Side Effects and Dangers

The following are some of the side effects that can occur after using levothyroxine:

  • Weight loss
  • Headache
  • Leg cramps or joint pain
  • Throw up
  • Fever
  • Diarrhea
  • Menstrual cycle changes
  • Hair loss
  • Appetite increases
  • Tremor

Check with your doctor if these side effects do not subside or get worse. See your doctor right away if you have an allergic reaction to a drug or a more serious side effect, such as:

  • Weakness, fatigue, or insomnia
  • restless ormood swings
  • Headache, leg cramps, or muscle pain, which gets worse
  • Diarrhea that occurs continuously or drastic weight loss
  • Chest pain, fast, irregular heartbeat, or heart palpitations
  • Fever, hot flashes, or excessive sweating