Sodium Iodide (123I) Injection 37 MBq/ml solution for injection

This medicinal product is for diagnostic use only.

Sodium Iodide (¹²³I) Injection is used as a diagnostic agent in the functional or morphological study of the thyroid gland by means of:

• Scintigraphy

• radioactive iodine uptake test

The 24 hours uptake data are generally used in calculating the therapeutic dose.

Posology

Adults

The recommended activity for an adult patient (70 kg) is between 3.7 and 14.8 MBq.

The lower activity (3.7 MBq) is recommended for uptake studies and the higher doses (11.1 - 14.8 MBq) for thyroid scintigraphy. However, for each individual case, the dose is decided by the specialist concerned.

Determination of the rate of thyroid iodine-123 uptake should be carried out in accordance with well- established standard procedures.

Paediatric population

The use in children and adolescents has to be considered carefully, based upon clinical needs and assessing the risk/benefit ratio in this patient group.

The activities to be administered to children and to adolescents may be calculated from the recommended range of adult activities and adjusted according to the following equation:

In young children, the activity of 14.8 MBq should be used in the equation to calculate the activity for children in order to obtain images of sufficient quality.

Sodium Iodide (¹²³I) Injection must be given as an intravenous injection; as a routine check, the activity in the injection should be measured immediately prior to administration. Imaging is performed 3-6 hours after administration.

Renal/Hepatic impairment

Sodium Iodide has not been studied in patients with significant renal or hepatic impairment. Careful consideration of the activity to be administered is required since an increased radiation exposure is possible in these patients.

Method of administration

For instructions on preparation of the medicinal product before administration, see section 12.

For patient preparation, see section 4.4.

Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

Potential for hypersensitivity or anaphylactic reactions:

If hypersensitivity or anaphylactic reactions occur, the administration of the medicinal product must be discontinued immediately and intravenous treatment initiated, if necessary. To enable immediate action in emergencies the necessary medicinal products and equipment such as endotracheal tube and ventilator must be readily available.

Individual benefit/risk justification:

For each patient, the radiation exposure must be justifiable by the likely benefit. The activity administered should in every case be as low as reasonably achievable to obtain the required diagnostic information.

Renal/Hepatic impairment:

Careful consideration of the benefit risk ratio in these patients is required since an increased radiation exposure is possible.

Paediatric population:

For information on the use in paediatric population, see section 4.2.

Careful consideration of the indication is required since the effective dose per MBq is higher than in adults (see section 11).

Patient preparation:

The patient should be well hydrated before the start of the examination and urged to void as often as possible during the first hours after the examination in order to reduce radiation.

General warnings:

Radiopharmaceuticals should be received, used and administered only by authorised persons in designated clinical settings. Their receipt, storage, use, transfer and disposal are subject to the regulations and/or appropriate licences of the competent official organisation.

Radiopharmaceuticals should be prepared by the user in a manner which satisfies both radiation safety and pharmaceutical quality requirements. Appropriate aseptic precautions should be taken.

Specific warnings:

This medicinal product contains less than 1 mmol sodium (23 mg) per dose, i.e. essentially 'sodium- free'.

Precautions with respect to environmental hazard see section 6.6.

The uptake of [¹²³I] iodide may be decreased by recent administration of iodinated contrast materials, by intake of stable iodine in any form, or by thyroid, antithyroid, and certain other drugs.

Accordingly, the patient should be questioned carefully regarding diet, previous medication, and procedures involving radiographic contrast media. Relevant medication including the ones mentioned below should be withheld prior to the administration of sodium [¹²³I] iodide.

Active substances: Withdrawal period prior to administration of sodium [¹²³I ]iodide

Antithyroid agents (e.g. carbimazole, methimazole, propyluracil), perchlorate: 1 week.

Salicylates, steroids, sodium nitroprusside, sodium sulfobromophthalein, anticoagulants, antihistamines, antiparasitics, penicillins, sulfonamides tolbutamide, thiopental: 1 week.

Phenylbutazone: 1-2 weeks.

Expectorants and vitamins: 2 weeks.

Natural or synthetic thyroid preparations (levothyroxine sodium, liothyronine sodium): 2-3 weeks.

Amiodarone, benzodiazepines, lithium: approx. 4 weeks.

Iodine-containing preparations for topical use: 1-9 months.

Intravenous contrast agents: 1-2 months

Iodine containing contrast agent: up to 1 year.

Paediatric population

Interaction studies have only been performed in adults.

Women of childbearing potential:

When an administration of radiopharmaceuticals to a woman of childbearing potential is intended, it is important to determine whether or not she is pregnant. Any woman who has missed a period should be assumed to be pregnant until proven otherwise. If in doubt about her potential pregnancy (if the woman has missed a period, if the period is very irregular, etc.), alternative techniques not using ionising radiation (if there are any) should be offered to the patient.

Pregnancy:

Radionuclide procedures carried out on pregnant women also involve radiation doses to the foetus. Only essential investigations should therefore be carried out during pregnancy, when the likely benefit far exceeds the risk incurred by the mother and foetus.

Breastfeeding:

Before administering a radiopharmaceutical to a mother who is breastfeeding consideration should be given to the possibility of delaying the administration of radionuclide until the mother has ceased breastfeeding and to what is the most appropriate choice of radiopharmaceutical, bearing in mind the secretion of activity in breast milk.

If the administration is considered necessary, breastfeeding should be interrupted for 1.5 - 3 days following the administration of iodine-123 that contains iodine-125 and/or iodine-124 as radio contaminant. Expressed feeds should be discarded.

Fertility:

No studies on fertility have been performed.

No studies on the effects on the ability to drive and use machines have been performed.

The frequencies of undesirable effects are defined as follows:

Very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to <1/1,000), very rare (<1/10,000) and not known (cannot be estimated from the available data).

Immune system disorders

Not known: Hypersensitivity

Exposure to ionising radiation is linked with cancer induction and a potential for development of hereditary defect. As the effective dose is 2.2 mSv when the maximal recommended activity of 14.8 MBq is administered these adverse reactions are expected to occur with a low probability.

Paediatric population

No data are available

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorization of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme (Website: www.mhra.gov.uk/yellowcard).

In the event of the administration of an overdose of [¹²³I]iodide, the absorbed dose to the patient should be reduced where possible by increasing the elimination of the radionuclide from the body by diuresis and frequent voiding of urine. A blocking agent such as potassium perchlorate should be used to minimise irradiation to the thyroid.

Paediatric population

No data are available.

Pharmacotherapeutic group: diagnostic radiopharmaceuticals, thyroid, sodium iodide (¹²³I), ATC code: V09FX02.

Pharmacodynamic effects

At doses used in diagnostic investigations, sodium iodide has not been observed to exert any pharmacodynamic effects.

Clinical efficacy and safety

See Pharmacodynamic effects.

Paediatric population

No data are available.

Distribution

Intravenously administered iodide is taken by the thyroid. About 20% of the available radioactivity enters the thyroid in one pass of the blood volume. Normal thyroid clearance of blood iodide is 20-50 ml/min with an increase to 100 ml/min in thyroid deficiency.

Organ Uptake

Peak levels of iodide occur in thyroid gland within a few hours so that diagnostic imaging can take place from one hour after dosing.

Elimination

See Half-life.

Half-life

The half-time of iodide elimination from the thyroid is estimated at 80 days so that the physical half- life of iodine-123 of 13 hours governs the temporal opportunity for imaging.

Without considering the thyroid uptake, the iodide leaves the body stream chiefly by urinary excretion (37-75%), while faecal excretion is low (about 1%).

Renal/Hepatic impairment

The pharmacokinetics in patients with renal or hepatic impairments has not been characterised.

Paediatric population

No data are available.

Known toxic effects of relatively high doses of sodium iodide are not relevant to this use of iodine- 123 to image the thyroid for diagnostic purposes.

No data are available from animal models about toxicity with repeated dose administration or about reproduction toxicity.

Sodium Iodide (¹²³I) Injection has not been investigated for mutagenicity and carcinogenic/oncogenic potential.

Acetic acid

Sodium hydroxide

Sodium thiosulphate

Sodium bicarbonate

Sodium chloride

Water for injections

In the absence of compatibility studies, this medicinal product must not be mixed with other medicinal products.

Can be used up to 36 hours post calibration time indicated on the label.

Once opened store in a refrigerator (2°C-8°C) and use within one working day.

Store below 25°C. Do not freeze.

For storage conditions after the first opening of the medicinal product, see section 6.3.

Store either in the original lead container or in equivalent shielding.

Storage of radiopharmaceuticals should be in accordance with national regulations on radioactive materials.

10 ml medicinal glass vial, closed with a Teflon coated rubber stopper and sealed with an aluminium cap. Each vial is enclosed in a lead container of appropriate thickness.

Pack size: 18.5 to 370 MBq.

Not all pack sizes may be marketed.

General warning

Radiopharmaceuticals should be received, used and administered only by authorized persons in designated clinical settings. Their receipt, storage, use, transfer and disposal are subject to the regulations and/or appropriate licenses of the competent official organization.

Radiopharmaceuticals should be prepared in a manner which satisfies both radiation safety and pharmaceutical quality requirements. Appropriate aseptic precautions should be taken.

If at any time in the preparation of this product the integrity of this container is compromised it should not be used.

Administration procedures should be carried out in a way to minimize risk of contamination of the medicinal product and irradiation of the operators. Adequate shielding is mandatory.

The administration of radiopharmaceuticals creates risks for other persons from external radiation or contamination from spill of urine, vomiting, etc. Radiation protection precautions in accordance with national regulations must therefore be taken.

Any unused medicinal product or waste material should be disposed of in accordance with local requirements