Medicine that boosts your levels of thyroid hormone is an easy way to treat your hypothyroidism. It's not a cure, but it can keep your condition under control for the rest of your life. Show
The most common treatment is levothyroxine (Levoxyl, Synthroid, Tirosint, Unithroid, Unithroid Direct), a man-made version of the thyroid hormone thyroxine (T4). It acts just like the hormone your thyroid gland normally makes. The right dose can make you feel a lot better. Starting on Thyroid Hormone TreatmentYour doctor will decide how much to give you based on your:
If you're older, or you have heart disease, you'll probably start on a small dose. Your doctor will slowly raise the amount over time until you see an effect. About 6 weeks after you start taking the medicine, you'll go back to your doctor for a blood test to check your thyroid hormone levels. Depending on what the results are, your dosage may change. Once your levels are stable, you'll see your doctor for a blood test every 6 months to a year. How to Take Your MedicineTo make sure your hypothyroidism stays under control: Stick with the same brand. Different types of thyroid hormone medicine may contain slightly different doses. That could mess with your hormone levels. Follow a schedule. Take your medicine at the same time each day. Aim for about an hour before a meal or at bedtime. Don't take it when you eat. Food, as well as some supplements, such as calcium, can affect the way your body uses it. Don't skip doses. If you miss one, take it as soon as you remember. You can take two pills in one day if you need to. Follow instructions carefully. Don't stop taking your medicine without first checking with your doctor. When Your Symptoms Don't Go AwayYou should start to feel better a few days after you begin taking medicine. But it may take a few months for your thyroid hormone levels to get back to normal. If your levels get better, but you still have symptoms like fatigue and weight gain, your doctor may need to change your treatment. The main risk of thyroid medicine is if you take too much of it, you can get symptoms of an overactive thyroid, like: If you have any of these, see your doctor for a blood test. They may need to lower your dose. Some medicines can affect the way your thyroid drug works, including: If you take one of these meds, talk to your doctor about how you should time taking your other medications based on when you take your thyroid medication. Stick With TreatmentYou'll need to keep taking thyroid medicine throughout your life to control your hormone levels. Keep up with your treatment and you'll see results. If taken correctly, thyroxine should enable patients to lead a normal life. However, there are some common problems which can affect management. Persistently elevated TSHPoor adherence is the most likely explanation of TSH remaining above the normal range. I advise patients to decant a week's supply of thyroxine into a separately labelled bottle and refill the bottle on the same day each week. If the patient discovers they have missed one (or more) doses they can take the missed doses in conjunction with their usual dose over the next few days. The absorption of thyroxine may be reduced by cholestyramine, colestipol, aluminium hydroxide, ferrous sulfate and possibly fibre. Two hours should elapse between use of thyroxine and these drugs. Symptoms do not respond to thyroxineHypothyroidism is often discovered on biochemical testing after patients present with non-specific complaints. While it is likely that symptoms such as muscle aches and pains, dry skin and dry hair and menstrual irregularity may respond to thyroxine, other symptoms such as lethargy, tiredness and fatigue, weight gain and depressive symptoms may have other causes. It is helpful to consider if the patient's symptoms are likely to be due to hypothyroidism before prescribing thyroxine and to tell them if you suspect that some of their symptoms are unlikely to respond. There is no proven benefit in adding liothyronine to the treatment of patients who have persistent symptoms despite taking thyroxine. Secondary hypothyroidismIf there is pituitary or hypothalamic disease, TSH is unreliable for diagnosing and monitoring thyroid function and fT4 should be used instead. A low fT4 will be found in secondary hypothyroidism and treatment should aim to maintain fT4 within the reference range. Most patients with secondary hypothyroidism will be hypogonadal and many will also be cortisol deficient. It is extremely important to consider cortisol deficiency before starting treatment with thyroxine in patients with pituitary and hypothalamic disease as its use will speed the metabolism of cortisol and can induce an adrenal crisis. When commencing thyroxine in secondary hypothyroidism it is therefore safest to also treat the patient with a corticosteroid (for example prednisone 5 mg daily). Subsequently, cortisol reserve can be assessed with an early morning cortisol measurement. A morning cortisol less than 100 nmol/L always indicates the need for ongoing steroid replacement. Results greater than 500 nmol/L indicate adequate reserve and values in between may require provocation tests.5 Drug-induced hypothyroidismLithium and iodine are the common causes of drug-induced hypothyroidism. Amiodarone, iodine-containing contrast media and kelp tablets are common sources of large doses of iodine. All forms of drug-induced hypothyroidism will usually resolve on withdrawal of the drug. Thyroxine can be used to control symptoms if required while recovery occurs. Lithium- and amiodarone-induced hypothyroidism are managed with thyroxine. The ongoing need for the lithium or amiodarone should be considered, but they can be continued if necessary. Pregnancy and lactationThyroxine requirements increase by 25-30% during pregnancy with increased requirements seen as early as the fifth week of pregnancy.6Children born to women whose hypothyroidism was inadequately treated in pregnancy are at increased risk of neuropsychological impairment.7 I advise women taking thyroxine who are planning to conceive to increase their dose of thyroxine by 30% at the confirmation of the pregnancy. TSH should be monitored every 8-10 weeks during pregnancy with further dose adjustments as necessary. The thyroxine dose returns to the pre-pregnancy dose after delivery whether the mother is breastfeeding or not. Transient hypothyroidismSome patients have transient hypothyroidism so it is appropriate to consider withdrawing the drug. For example, women who develop hypothyroidism in the postpartum period (postpartum thyroiditis) may not require long-term thyroxine replacement. In some patients a clear cause of hypothyroidism is not established, but the cause will often have been the hypothyroid phase of subacute (de Quervain's) thyroiditis or possibly iodine-induced hypothyroidism. Other patients may ask if they can stop thyroxine therapy. If treatment is stopped it usually takes four weeks for the TSH to rise, but it can be tested earlier if symptoms occur. The onset of symptoms and a rising TSH show an ongoing need for thyroxine and patients can immediately recommence their previous dose. What is the drug of choice for thyroid replacement?Thyroid Hormone Replacement
The main medication used to treat hypothyroidism is levothyroxine sodium (Synthroid, Levoxyl, and Levothroid), a synthetic version of thyroxine (T4), a thyroid hormone your body produces naturally.
What is the best thyroid replacement?The FDA has approved levothyroxine for the treatment of hypothyroidism. It is the most commonly prescribed form of thyroid replacement, largely because it has the most data to support its use. There are several formulations of levothyroxine, but some brand names include Synthroid, Levoxyl, and Levo-T.
What is the most frequently prescribed thyroid medication?The most common treatment is levothyroxine (Levoxyl, Synthroid, Tirosint, Unithroid, Unithroid Direct), a man-made version of the thyroid hormone thyroxine (T4).
Why T4 are preferred than T3 in thyroid replacement therapy?The benefit of taking only T4 therapy is that you're allowing your body to perform some of the actions it is meant to do, which is taking T4 and changing it into T3. The half-life of T4 is also longer compared to T3 (7 days versus 24 hours), which means that it will stay for a longer time in your body after ingestion.
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