Interactions : אינטראקציות

4.5 Interaction with other medicinal products and other forms of interaction
Many pharmacologically active substances interact with radioiodide. Various interaction mechanisms exist which can affect the protein binding, the pharmacokinetics or the dynamic effects of labelled iodide. As a consequence, it should be considered that the thyroid uptake might be reduced.
Therefore, a full drug history should be taken and relevant medicinal products are required to be withheld prior to the administration of sodium iodide (131I).

For example, the treatment with the following substances should be discontinued: 
Active substances                              Withdrawal period before administration of sodium iodide (131I).
Antithyroid medicinal products (e.g.           1 week before starting treatment till carbimazole, methimazole, propyluracil),       several days after perchlorate
Salicylates, corticosteroids, sodium           1 week.
nitroprusside, sodium sulfobromophthalein, anticoagulants,
antihistamines, antiparasitics, penicillins,
sulphonamides, tolbutamide, thiopental
Phenylbutazone                                1 to 2 weeks.
Containing iodine                             approximately 2 weeks.
expectorants and vitamins
Thyroid hormone preparations                   Triiodothyronine 2 weeks Thyronine 6 weeks.
Benzodiazepines, lithium                       Approximately 4 weeks.
Amiodarone*                                    3 to 6 months
Containing iodine preparations for topical 1 to 9 months.
use
Water-soluble iodine-containing contrast       6 to 8 weeks media
Lipo-soluble iodine-containing contrast up to 6 months media
* Due to the long half-life of amiodarone, iodine uptake in the thyroid tissue can be decreased for several months.