Interactions : אינטראקציות

4.5   Interaction with other medicinal products and other forms of interaction
Many pharmacologically active substances are known to interact with radioiodide. These may hap- pen by a variety of mechanisms which can affect the protein binding, the pharmacokinetics or in- fluence the dynamic effects of labelled iodide. As a consequence, it should be considered that the thyroid uptake might be reduced. It is therefore necessary to take a full drug history and ascertain whether any medicinal products are required to be withheld prior to the administration of sodium iodide I-131.

For example, the treatment with the following substances should be discontinued: 
Active substances                          Period of rest before administration of I-131 antithyroid agents (e.g. carbimazole,      withheld 1week before starting treatment till several methimazole, propyluracil), perchlo-       days after rate salicylates, steroids, sodium nitroprus-   1 week side, sodium sulfobromophthalein,
anticoagulants, antihistamines, antipar- asitics, penicillins, sulphonamides,
tolbutamide, thiopentone phenylbutazone                             1 - 2 weeks
 containing iodine expectorants and         approx. 2 weeks vitamins thyroid hormone preparations               Triiodothyronine 14 days thyroxine 4-5 weeks amiodarone*, benzodiazepines, lithium      approx. 4 weeks containing iodine preparations for top-    1 - 9 months ical use containing iodine contrast media           up to 1 year

* In case of amiodarone, a reduced uptake in the thyroid gland during several months is possible due to the long half-life of this agent.