lMEDICINAL FORMS
There can be variation in the licensing of different medicines
containing the same drug. Forms available from special-order
manufacturers include: oral suspension, oral solution
Tablet
▶Propylthiouracil (Non-proprietary)
Propylthiouracil 50 mgPropylthiouracil 50 mg tablets|
56 tabletP£ 57. 58 DT = £ 55. 21 | 100 tabletP£ 98. 59 –
£ 115. 98
VITAMINS AND TRACE ELEMENTS
Iodide with iodine
lINDICATIONS AND DOSE
Thyrotoxicosis (pre-operative)
▶BY MOUTH USING ORAL SOLUTION
▶Neonate: 0. 1 – 0. 3 mL 3 times a day.▶Child: 0. 1 – 0. 3 mL 3 times a day
Neonatal thyrotoxicosis
▶BY MOUTH USING ORAL SOLUTION
▶Neonate: 0. 05 – 0. 1 mL 3 times a day.Thyrotoxic crisis
▶BY MOUTH USING ORAL SOLUTION
▶Child 1 month–1 year: 0. 2 – 0. 3 mL 3 times a daylCAUTIONSChildren.not for long-term treatment
lSIDE-EFFECTSConjunctivitis.depression (long term use).
erectile dysfunction (long term use).excessive tearing.
headache.hypersensitivity.increased risk of infection.
influenza-like illness.insomnia (long term use).rash.
salivary gland pain
lPREGNANCYNeonatal goitre and hypothyroidism.
lBREAST FEEDINGStop breast-feeding. Danger of neonatal
hypothyroidism or goitre. Appears to be concentrated in
milk.
lDIRECTIONS FOR ADMINISTRATIONFor oral solution, dilute
well with milk or water.
lMEDICINAL FORMS
No licensed medicines listed.
8.2 Hypothyroidism
Thyroid hormones
Overview
Thyroid hormones are used in hypothyroidism (juvenile
myxoedema), and also in diffuse non-toxic goitre, congenital
or neonatal hypothyroidism, and Hashimoto’s thyroiditis
(lymphadenoid goitre). Neonatal hypothyroidism requires
prompt treatment to facilitate normal development.
Levothyroxine sodium (thyroxine sodium) below is the
treatment of choice formaintenancetherapy.
Doses for congenital hypothyroidism and juvenile
myxoedema should be titrated according to clinical
response, growth assessment, and measurement of plasma
thyroxine and thyroid-stimulating hormone concentrations.
In congenital hypothyroidism higher initial doses may
normalise metabolism more quickly, with associated
beneficial effects on mental development.
Liothyronine sodium p. 486 has a similar action to
levothyroxine sodium but is more rapidly metabolised and
has a more rapid effect. Its effects develop after a few hours
and disappear within 24 to 48 hours of discontinuing
treatment. It may be used insevere hypothyroid stateswhen a
rapid response is desired.
Liothyronine sodium by intravenous injection is the
treatment of choice inhypothyroid coma. Adjunctive therapy
includes intravenousfluids, hydrocortisone p. 440 , and
treatment of infection; assisted ventilation is often required.THYROID HORMONES
Levothyroxine sodium
(Thyroxine sodium)
lINDICATIONS AND DOSE
Hypothyroidism
▶BY MOUTH
▶Neonate:Initially 10 – 15 micrograms/kg once daily (max.
per dose 50 micrograms); adjusted in steps of
5 micrograms/kg every 2 weeks, alternatively adjusted in
steps of 5 micrograms/kg as required; maintenance
20 – 50 micrograms daily, levothyroxine should be taken
at the same time each day, preferably 30 minutes before
meals, caffeine-containing drinks, or other medicines;
this could be before breakfast or another more
convenient time.▶Child 1 month–1 year:Initially 5 micrograms/kg once
daily (max. per dose 50 micrograms); adjusted in steps
of 10 – 25 micrograms every 2 – 4 weeks until
metabolism normalised; maintenance
25 – 75 micrograms daily, levothyroxine should be
taken at the same time each day, preferably 30 minutes
before meals, caffeine-containing drinks, or other
medicines; this could be before breakfast or another
more convenient time
▶Child 2–11 years:Initially 50 micrograms once daily;
adjusted in steps of 25 micrograms every 2 – 4 weeks
until metabolism normalised; maintenance
75 – 100 micrograms daily, levothyroxine should be
taken at the same time each day, preferably 30 minutes
before meals, caffeine-containing drinks, or other
medicines; this could be before breakfast or another
more convenient time
▶Child 12–17 years:Initially 50 micrograms once daily;
adjusted in steps of 25 – 50 micrograms every 3 – 4 weeks
until metabolism normalised; maintenance
100 – 200 micrograms daily, levothyroxine should be
taken at the same time each day, preferably 30 minutes
before meals, caffeine-containing drinks, or other
medicines; this could be before breakfast or another
more convenient time
Hyperthyroidism (blocking-replacement regimen) in
combination with carbimazole
▶BY MOUTH
▶Child:Therapy usually given for 12 to 24 months
(consult product literature or local protocols)lCAUTIONSCardiac disorders (monitor ECG; start at low
dose and carefully titrate).diabetes insipidus.diabetes
mellitus (dose of antidiabetic drugs including insulin may
need to be increased).long-standing hypothyroidism.
panhypopituitarism (initiate corticosteroid therapy before
starting levothyroxine).predisposition to adrenal
insufficiency (initiate corticosteroid therapy before
starting levothyroxine)
lINTERACTIONS→Appendix 1 : thyroid hormones
lSIDE-EFFECTSAlopecia.angina pectoris.anxiety.
arrhythmias.arthralgia.diarrhoea.dyspnoea.epiphyses
premature fusion.fever.flushing.headache.heat
intolerance.hyperhidrosis.idiopathic intracranial
hypertension.insomnia.malaise.menstruation irregular.
muscle spasms.muscle weakness.oedema.palpitations.
skin reactions.thyrotoxic crisis.tremor.vomiting.weight
decreasedBNFC 2018 – 2019 Hypothyroidism 485
Endocrine system6