Source: Health Products Regulatory Authority (IE) Revision Year: 2021 Publisher: Aspen Pharma Trading Limited, 3016 Lake Drive, Citywest Business Campus, Dublin 24, Ireland
Levothyroxine 25–200 micrograms:
Levothyroxine 25–100 micrograms:
Levothyroxine 100/150/200 micrograms:
The dosing information serves as a guideline. The individual daily dose should be determined by laboratory diagnostic tests and clinical examinations. If any residual thyroid function remains, a lower replacement dose may be sufficient.
In elderly patients, patients with coronary heart disease and patients with severe or chronic hypothyroidism, thyroid hormone treatment must be initiated with particular caution, i.e. by selecting a low initial dose and increasing it slowly and at longer intervals, with frequent thyroid hormone monitoring. Experience has shown that a lower dose is also sufficient in patients with a low body weight and in patients with large goitres. As the Levothyroxine 25 microgram tablets can be divided into equal halves, a starting dose of 12.5 micrograms can be used.
As T4 or fT4 levels may be increased in some patients, determination of the serum TSH concentration is better suited for monitoring the treatment regimen.
The maintenance dose is generally 100 to 150 micrograms per m² body surface area per day.
For neonates and infants with congenital hypothyroidism, where rapid replacement is important, the initial recommended dosage is 10 to 15 micrograms per kg BW per day for the first 3 months.
Thereafter, the dose should be adjusted individually according to the clinical findings and thyroid hormone and TSH values.
For children with acquired hypothyroidism, the initial recommended dosage is 12.5-50 micrograms per day. The dose should be increased gradually every 2 to 4 weeks according to the clinical findings and thyroid hormone and TSH values until the full replacement dose is reached.
Infants should be given the total daily dose at least half an hour before the first meal of the day.
The total daily dose is taken in the morning on an empty stomach at least half an hour before breakfast. The tablets are swallowed whole, without chewing, with some liquid.
Infants are given the total daily dose at least half an hour before their first meal of the day. For this, the tablet is allowed to dissolve in some water (10-15 ml) and the resulting fine dispersion (NB: to be freshly prepared for each dose) is administered with some more liquid (5-10 ml).
| Indication | Dose (Micrograms of levothyroxine sodium/day) | |
|---|---|---|
| Hypothyroidism: | ||
| Adults initially | 25-50 | |
| followed by | 100-200 | |
| (increased at 2 to 4 week intervals in increments of 25-50 micrograms) | ||
| Prophylaxis against goitre recurrence: | 75-200 | |
| Benign euthyroid goitre: | 75-200 | |
| Co-therapy in the antithyroid treatment of hyperthyroidism: | 50-100 | |
| Post thyroidectomy due to thyroid malignancy: | 150-300 | |
| Thyroid suppression scintigraphy: | Levothyroxine 100 microgram tablets | 200 micrograms (equivalent to 2 tablets)/day (for 14 days until the scintigram is performed) |
| Levothyroxine 150 microgram tablets | 150 micrograms (equivalent to 1 tablet)/day (for 14 days until the scintigram is performed) | |
| Levothyroxine 200 microgram tablets | 200 micrograms (equivalent to 1 tablet)/day (for 14 days until the scintigram is performed) | |
In most cases, treatment is lifelong when used in hypothyroidism and thyroidectomy due to thyroid malignancy, several months or years and even lifelong when used for euthyroid goitre and prophylaxis against goitre recurrence, or is dependent on the duration of the antithyroid medicinal product when used as co-therapy in the treatment of hyperthyroidism.
For the treatment of euthyroid goitre, a treatment period of 6 months up to 2 years is necessary. If treatment with Levothyroxine sodium has failed to achieve the desired success within this time, other therapeutic options should be considered.
For performing thyroid suppression tests, 150-200 micrograms of levothyroxine sodium is taken daily for 14 days.
In individual cases, e.g. in the presence of cardiac problems, slow up titration of the levothyroxine sodium dose should be preferred in elderly patients, together with regular monitoring of the TSH level.
Hyperthyroidism may result from treatment imbalance or levothyroxine overdose. An increased T3 level is a more reliable sign of an overdose than elevated T4 or fT4 levels.
In addition to exaggeration of side effects the following symptoms may be seen: agitation, confusion, irritability, hyperactivity, headache, sweating, mydriasis, tachycardia, arrhythmias, tachypnoea, pyrexia, increased bowel movements and convulsions. Psychiatric symptoms associated with hyperthyroidism may also occur, including affect lability, fatigue, anxiety and nervousness. The appearance of clinical hyperthyroidism may be delayed for up to five days.
Discontinuation of treatment and a follow up examination are recommended, depending on the extent of the overdose.
In cases of intoxication incidence (suicide attempts) in humans, doses of up to 10 mg levothyroxine have been tolerated without complications. Serious complications, such as a threat to vital functions (respiration and circulation), are not anticipated unless coronary heart disease is present. Nevertheless, cases of thyrotoxic crisishave been occasionally reported following massive or chronic intoxication, leading to seizures, cardiac arrhythmias, heart failure and coma. Individual cases of sudden cardiac death have been reported in patients with many years of levothyroxine abuse.
Exceptional cases of seizures have been reported in epileptic patients when levothyroxine therapy is initiated, particularly when the dose of levothyroxine is increased rapidly.
Excessive levothyroxine use may cause decreased bone mineral density, particularly in postmenopausal women.
Treatment is mostly symptomatic and supportive.
The goal of therapy is restoration of clinical and biochemical euthyroid state by omitting or reducing the levothyroxine dosage, and other measures as needed depending on clinical status.
In the event of an acute overdose, gastrointestinal absorption can be reduced by administering medicinal charcoal. For severe beta sympathomimetic effects such as tachycardia, state of anxiety, agitation and hyperkinesia, symptoms can be alleviated with beta receptor blockers (propranolol), diazepam and/ or chlorpromazine. Antithyroid agents are not indicated, as the thyroid is already fully quiescent.
At extremely high doses (suicide attempt), plasmapheresis may be of assistance.
An overdose with levothyroxine demands a prolonged period of monitoring. Onset of symptoms may be delayed by up to 6 days, due to the gradual conversion of levothyroxine to liothyronine.
2 years.
For Oroxine 25 and 50 microgram tablets:
After opening of the HDPE container the tablets should be used within 2 months.
For Oroxine 75, 100, 125, 150, 175, 200 microgram tablets:
After opening of the HDPE container the tablets should be used within 112 days.
Store below 25°C.
High density polyethylene (HDPE) bottles, closed with white polypropylene (PP) screw caps with foil heat induction seals, and with a 1.0 g white polypropylene canister containing oxygen absorber. The canister (oxygen absorber) should remain inside the bottle during the in-use period.
For Oroxine 25 and 50 microgram tablets: 28, 50, 60 tablets.
For Oroxine 75, 100, 125, 150, 175, 200 microgram tablets: 28, 50, 60, 84, 90, 100, 112 tablets.
Not all pack sizes may be marketed.
No special requirements.
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
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