Which Are The Levothyroxine Side Effects

levothyroxine side effectsLevothyroxine is a drug used to treat mainly thyroid hormone deficiency but in some cases, it’s also recommended for the prevention of thyroid cancer recurrence. It’s a drug synthesized from the thyroid hormone but it’s slightly different from the natural thyroid hormone.

Levothyroxine also has the ability to diminish the thyotropin (the thyroid-stimulating hormone), which is considered one of the main triggers of goitre. Therefore levothyroxine is a drug prescribed to treat the symptoms of goitre.

Levothyroxine Side Effects

One of the main levothyroxine side effects is hyperthyroidism that’s why the dosage of this drug should be carefully controlled. Not only that a higher dose than necessary of levothyroxine can induce hyperthiroidism symptoms, like the swelling of the thyroid gland, but this can also lead to eating disorders, gastrointestinal disorders (nausea, vomiting, stomach pain), behavioral disorders, (confusion, restlessness, anxiousness), and also heart problems (tachycardia and palpitations). In case of severe overdose, the levothyroxine side effects are hypoglicemia, fever, heart attack and coma.

Heart problems are frequently shown in patients that undergo a prolongued treatment with levothyroxine. That’s why it’s important that the treatment with this hormone supplement is kept under strict supervision on patients that have a history with heart disease, heart attacks or heart problems.

Lastly, one of the levothyroxine side effects is a decrease of bone mineral, which may lead to osteoporosis. In general, older women under treatment with slightly higher doses levothyroxine are exposed to this adverse effect. However, this levothyroxine side effect can be alleviated by the administration of vitamin D and calcium.

Generally, it’s less likely for levothyroxine to show any side effects, if it’s prescribed and administered correctly, and of course, it’s not taken along with the wrong medication or diet.

Levothyroxine Interactions

Osteoporosis is one of the possible levothyroxine side effects and to avoid this condition some patients are also recommended a treatment with calcium. However, calcium and also iron, magnesium and aluminium can reduce the absorption of levothyroxine. Therefore, any calcium, aluminium, magnesium or iron-based supplements should be taken after four hours from the intake of levothyroxine. There are also other drugs that may interfere with the absorption of this drug. These are: sodium polystyrene sulfonate (Kayexalate), simethicone and some of the cholesterol blockers like colestyramine and colestipol.

In conjunction with ketamine, levothyroxine side effects involving heart problems like tachycardia, or increased hypertension may occur. Also, lithium increases the risk of hyperthyroidism, while some anti-depressive drugs, (in general, tetracyclic and tricyclic) can increase the toxicity levels of levothyroxine.

There are certain food products that can also interfere with the absorbtion of the drug. These are grapefruit juice, due to its contents of furanocoumarins and soy products.

Word of Advice:

In general, dosage of levothyroxine should be strictly controlled. Needless to say, it depends on the body weight and the other treatments and conditions of the patient, and only a physician can determine correctly the appropriate dose. Also, regular visits to your doctor are indicated in case of medication with this drug, for dosage adjustments if it’s the case.

Levothyroxine should be administered on an empty stomach, one hour before a meal. Also, try to avoid consuming any soy-based products after taking a dose, or at least up to 4 hours after the a dose.

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