Hypersensitivity to the active substance or to any of the excipients.
Information on contraindications when using a kit for radiopharmaceutical preparation should be sought in the SmPC and PIL of the kit for radiopharmaceutical preparation.
4.4 Special warnings and precautions for use
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 immediately available.
For each patient, exposure to ionising radiation must be justifiable on the basis of likely clinical benefit. The activity administered must be such that the resulting radiation is as low as reasonably achievable bearing in mind the need to obtain the intended diagnostic result.
Renal impairment, hepatic impairment
Careful consideration of the benefit risk ratio in these patients is required since an increased radiation exposure is possible.
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 section11).
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. Thyroid blocking is of special importance when performing cerebral scintigraphy in the paediatric population.
Premedication of patients with thyroid-blocking medicinal products may be necessary for certain indications.
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.
Before the application of Sodium [99mTc]pertechnetate-solution for scintigraphy of Meckel’s diverticulum the patient should keep an empty stomach for 3 to 4 hours to reduce intestinal peristalsis.
In thyroid gland scintigraphy, salivary gland scintigraphy or location of ectopic gastric mucosa concomitant application of Sodium perchlorate is associated with reduced uptake of radioactivity in glandular tissue.
In cerebral scintigraphy there is also an uptake of Sodium Pertechnetate (99mTc) in the plexus choroideus that may be misinterpreted as misfunction of the blood-brain barrier (fals-positive finding). To reduce the likelihood of misinterpretation and to reduce radiation exposure pretreatment with Perchlorate is recommended as Perchlorate reduces uptake of Sodium Pertechnetate (99mTc) to the plexus choroideus.
In Shuntscintigraphy blocking of the thyroid gland to reduce radiation exposure is also necessary as with shunts with normal passability complete activity reaches the peritoneal cavity where it is absorbed and systemically distributed.
After in vivo labelling of erythrocytes using stannous ions for reduction Sodium Pertechnetate (99mTc) is primarily built into erythrocytes, therefore Meckel scintigraphy should be performed before or some days after in vivo labelling of erythrocytes.
This medicinal product contains 0.15 mmol/ml (3.54 mg/ml) sodium. To be taken into consideration by patients on a controlled sodium diet.
4.5 Interaction with other medicinal products and other forms of interaction
Drug interactions have been reported in brain scintigraphy where there can be increased uptake of [99mTc]pertechnetate in the walls of cerebral ventricles as a result of methotrexate-induced ventriculitis.
In abdominal imaging, drugs such as atropine, isoprenaline and analgesics can result in a delay in gastric emptying and redistribution of [99mTc]pertechnetate.
Thyroid hormones, iodine, iodide, perchlorate, thiocyanate, aluminium containing antacids, sulfonamides and products containing stannous (II) ions may to increased concentrations of Sodium Pertechnetate (99mTc) in the vascular space, in the case of stannous (II) ions and sulfonamides the concentration of Sodium Pertechnetate (99mTc) in red blood cells may be increased, and there may be decreased accumulation in plasma and cerebral lesions. Such medicines should be discontinued several days before the procedure.
Iodine containing radiologic contrast media and perchlorate may decrease uptake of 99mTc-Pertechnetate to digestive mucous. Barium sulphate absorbs most of gamma radiation of the tracer. Scintigraphy of Meckel’s diverticulum should therefore be performed at the earliest 2-3 days after application of these substances. Laxatives may increase transport of 99mTc-Pertechnetate from the stomach and the intestine and should not be taken before performing scintigraphy of Meckel’s diverticulum.
The possible types of interactions following intravenous administration of a 99mTc-labelled pharmaceutical preparation will be dependent on the specific compound being used. Such information can be found in the SmPC of the kit used for radiopharmaceutical preparation.
Where it is necessary to administer radioactive medicinal products to a woman of childbearing potential, information should always be sought about pregnancy. Any woman who has missed a period should be assumed to be pregnant until proven otherwise. Where uncertainty exists, it is particularly important that the radiation exposure should be the minimum consistent with achieving the desired clinical information. Alternative techniques which do not involve ionising radiation should be considered.
Technetium-99m (as free pertechnetate) has been shown to cross the placental barrier.
Radionuclide procedures carried out on pregnant women also involve radiation doses to the foetus. Only imperative investigations should be carried out during pregnancy, when the likely benefit exceeds the risk incurred by the mother and the foetus. Direct administration of 800 MBq sodium [99mTc]pertechnetate to a patient results in an absorbed dose to the uterus of 6.5 mGy. Following pretreatment of patients with a blocking agent, administration of 800 MBq sodium [99mTc]pertechnetate results in an absorbed dose to the uterus of 5.3 mGy. Administration of 925 MBq technetium-99m labelled red blood cells results in an absorbed dose to the uterus of 4.3 mGy. Doses above 0.5 mGy should be regarded as a potential risk to the foetus.
Before administering a radioactive medicinal product to a woman who is breast feeding, consideration should be given as to whether the investigation could be reasonably delayed until the mother has ceased breast feeding and as to whether the most appropriate choice of radiopharmaceutical has been made. If the administration is considered necessary, breast feeding should be interrupted and the expressed feeds discarded. Breast feeding can be restarted when the activity level in the milk will not result in a radiation dose to the child greater than 1mSv. If the administration is considered necessary, breastfeeding should be interrupted for 12 hours and the expressed feeds discarded.
4.7 Effects on ability to drive and use machines
No studies on the effects on the ability to drive and use machines have been performed.
4.8 Undesirable effects
Summary of the safety profile:
Information on adverse reactions is available from spontaneous reporting. The reported reaction types are hypersensitivity or anaphylactoid reactions, unspecific systemic reactions, as well as injection site reactions.
Sodium pertechnetate (99mTc) from the Drytec radionuclide generator is used for radioactive labeling of a variety of compounds. These medicinal products generally have a higher potential for adverse reactions than 99mTc, and therefore the reported adverse reactions are rather related to the labelled compounds than to 99mTc.
Possible side-effects following the intravenous administration of 99mTc-labelled pharmaceuticals prepared by radiolabelling with Sodium (99mTc) Pertechnetate Solution will be dependent on the specific pharmaceutical being used. Such information can be found in the SmPC of the kit used for radiopharmaceutical preparation.
Tabulated list of adverse reactions
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
Frequency unknown*: Anaphylactoid reactions (e.g. Dyspnoea, coma, urticaria, erythema, rash, pruritus, oedema at various location e.g. face oedema)
General disorders and administration site conditions
Frequency unknown*: Injection site reactions (e.g. Cellulitis, pain, erythema, swelling)
* Adverse reactions derived from spontaneous reporting
Unspecific systemic reactions and gastrointestinal disorders are rather considered to be related to the examinational setting than to technetium (99mTc), especially in anxious patients.
Injection site reactions are related to extravasation of the radioactive material during the injection and may range from local swelling up to cellulitis.
Exposure to ionising radiation is linked with cancer induction and a potential for development of hereditary defects.. As the effective dose is 10.4 mSv when the maximal recommended activity of 800 MBq is administered these adverse reactions are expected to occur with a low probability.
For most diagnostic investigations using a nuclear medicine procedure, the effective dose is less than 20 mSv. Higher doses may be justified in some clinical circumstances.
In the event of the administration of a radiation overdose with sodium [99mTc]pertechnetate, the absorbed dose should be reduced where possible by increasing the elimination of the radionuclide from the body. Measures to reduce possible harmful effects include frequent voiding of urine and promotion of diuresis and faecal excretion.
Very little supportive treatment can be undertaken in the event of an overdose of technetium-99m labelled red blood cells since elimination is dependent on the normal haemolytic process.
The uptake in the thyroid, salivary glands and the gastric mucosa can be significantly reduced when sodium perchlorate is given immediately after an accidentally high dose of sodium pertechnetate (99mTc) was administered.