n autoimmune disease or following a viral
infection. The starting dose is 12.5 – 50 micrograms per day. The
dose will then be increased every 2 - 4 weeks depending on how
your child responds to the medicine.
This is a condition where children and adolescents develop severe
hypothyroidism (produce very low levels of thyroid hormones). The
starting dose is 25 micrograms every day. The dose will then be
increased by 25 micrograms every 2 – 4 weeks until your child
shows mild symptoms of hyperthyroidism (a condition where the
thyroid gland produces too much thyroxine). The dose will then be
If you take more Levothyroxine tablets than you should
If you (or someone else) swallow a lot of the tablets at the same time,
or you think a child may have swallowed some, contact your nearest
hospital casualty department or tell your doctor immediately. Signs
of an overdose may include: fever, chest pain (angina), racing or
irregular heartbeat, muscle cramps, headache, restlessness,
flushing, sweating and diarrhoea. These signs can take up to 5 days
to appear. Take any remaining tablets and this leaflet with you so that
the medical staff knows exactly what you have taken.
If you forget to take Levothyroxine tablets:
If you forget to take a dose take it as soon as you remember unless it
is nearly time for your next dose. Do not take a double dose to make
up for a forgotten dose. If you forget to give your child their dose,
contact your doctor or pharmacist for further advice.
If you stop taking Levothyroxine tablets:
These tablets are for long term use. You may need to take them for
the rest of your life. Do not stop taking the tablets unless your doctor
has told you to do so.
If you have any further questions on the use of this medicine, ask
your doctor, pharmacist or nurse.
4. POSSIBLE SIDE EFFECTS
Like all medicines, this medicine can cause side effects, although not
everybody gets them.
Stop taking the tablets and go to hospital at once if you have:
• a rare allergic reaction such as swelling of the face, tongue, lips
and throat, difficulty breathing, severe itching of your skin with
raised lumps, joint pain, sensitivity to the sun, general feeling of
being unwell. You may need urgent medical attention.
Some patients may experience a severe reaction to high
levels of thyroid hormone. This is called a “thyroid crisis” and
you should contact your doctor immediately if you have any
of the following symptoms:
• very high temperature; fast heart rate; irregular heartbeat; low
blood pressure; heart failure; jaundice; confusion; fits and coma.
Tell your doctor or pharmacist if any of the following side
effects continue, get worse or if you notice any other side
effects not listed.
Most of the side effects are similar to the symptoms of
hyperthyroidism (where the thyroid gland makes too much thyroxine)
and are due to your dose of the medicine being too high. They will
usually disappear after reducing the dose or stopping the tablets.
However, you must not change the dose or stop the tablets
without talking to your doctor first.
Not known (frequency cannot be estimated from the available
• high temperature, sweating
• weight loss
• tremor, restlessness, excitability, difficulty sleeping (insomnia)
• increased pressure around the brain in children that is not caused
by a tumour or other diseases (benign intracranial hypertension)
• chest pain (angina), pounding, irregular or fast heartbeat
• diarrhoea, vomiting
• muscle cramps, muscle weakness
• deformity of the skull in infants caused by the early closure of
joints in the skull bone (craniostenosis)
• growth in children may slow or stop due to changes in bone
• irregular periods
• intolerance to heat
• temporary hair loss in children.
Reporting of side effects:
If you get any side effects, talk to your doctor, pharmacist or nurse.
This includes any possible side effects not listed in this leaflet. You
can also report side effects directly via the Yellow Card Scheme at:
By reporting side effects you can help provide more information on
the safety of this medicine.
5. HOW TO STORE LEVOTHYROXINE