Levotiron T4 100mg (Levothyroxine Sodium) is a medicine used to treat an underactive thyroid gland (hypothyroidism).

The thyroid gland makes thyroid hormones which help to control energy levels and growth. Levothyroxine is taken to replace the missing thyroid hormone thyroxine.

Levothyroxine is only available on prescription. It comes as tablets or as a liquid that you swallow.

• Levothyroxine is a synthetic version of a hormone called thyroxine. It replaces thyroxine if your thyroid gland cannot produce it and prevents the symptoms of hypothyroidism.
• Levothyroxine starts working straight away, but it may be several weeks before your symptoms start to improve.
• The most common side effects of levothyroxine are caused by taking a bigger dose than you need. Your doctor can lower your dose to help reduce any side effects.
• Before you start taking levothyroxine, your doctor will do a blood test. Once you start taking the medicine you’ll have regular blood tests to see how well it’s working.
• Levothyroxine doses need to be carefully monitored during pregnancy. If you’re planning to become pregnant or think you may be pregnant, it’s important to talk to your doctor to get the right care for you and your baby.

Levothyroxine can be taken by most adults and children. However, it’s not suitable for some people.

Check with your doctor before taking levothyroxine if you:

• have ever had an allergic reaction to levothyroxine or any other medicine
• you have an overactive thyroid that produces too much thyroid hormone (thyrotoxicosis)
• have a health problem that affects your adrenal glands (your doctor will be able to tell you if you’re not sure)
• have a heart problem including angina, heart disease or heart failure
• have high blood pressure
• have ever had a heart attack
• have diabetes – the dose of your diabetes medicine may need to change because levothyroxine can raise blood sugar levels

Take levothyroxine once a day in the morning, ideally at least 30 minutes before having breakfast or a drink containing caffeine, like tea or coffee.

Food and caffeinated drinks can both stop your body taking in levothyroxine properly so it does not work as well.

If you stop taking levothyroxine, your symptoms are likely to come back.

Dosage and strength

The dose of levothyroxine varies from person to person.

You may need to take several different tablets to make up your dose. Your doctor will tell you how many tablets to take each day.

Levothyroxine comes in 12.5 microgram, 25 microgram, 50 microgram, 75 microgram and 100 microgram tablets.

If you’re taking levothyroxine as a liquid, 5ml can have 25 micrograms, 50 micrograms, 100 micrograms or 125micrograms in it.

Although starting doses are usually the same, the dose of levothyroxine you end up taking, or how quickly the dose is increased, depends on your symptoms, hormone levels, age and whether you have any other health problems.

Adults usually start with a dose between 50 micrograms and 100 micrograms taken once a day. This may be increased gradually over a few weeks to between 100 micrograms and 200 micrograms taken once a day.

Some people, such as over-50s or people with heart disease, may start on a lower dose.

How to take levothyroxine

Swallow the tablets whole with a drink of water.

Levothyroxine is available as a liquid for children and people who find it difficult to swallow tablets. It’s available in different strengths.

If you or your child are taking levothyroxine as a liquid, it will usually come with a plastic syringe or spoon to help you measure out the right dose.

If you do not have a syringe or measuring spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not give the right amount.

If you forget to take it

If you forget to take a dose, take it as soon as you remember, unless it’s almost time for your next dose. In this case just skip the forgotten dose and take the next one at the usual time.

Do not take 2 doses together to make up for a missed dose.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

If you take too much

Taking more than your prescribed dose of levothyroxine can give you symptoms such as a racing heartbeat (palpitations).