Does Sodium Iodide I 131 Interact with Ethionamide?
Sodium Iodide I 131 and Ethionamide have a unknown drug interaction according to U.S. FDA drug labeling data. Table 4 Pharmaceuticals / OTCs / Agents Blocking Radioiodine Uptake Type of Medication Recommended time of withdrawal Thionamide medications (e.g., propylthiouracil, methimazole, carbimazole) 3 days Multivitamins containing iodide 10 days Natural or synthetic thyroid hormones triiodothyronine thyroxine 2 weeks 4 weeks Iodide-containing foods: iodized salt, dairy products, egg yolks, seafood, turkey and liver 2 weeks Kelp, agar, carrageenan, Lugol solution 3 weeks Saturated solution of potassium iodide 3 weeks Topical iodide (e.g., surgical skin preparation) 3 weeks Intravenous radiographic contrast agents Water soluble Lipophilic 2 months 6 months Amiodarone 6 months Many pharmacologic agents are known to interact with radioiodide. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Unknown
- Management
- Consult your pharmacist
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Sodium Iodide I 131 and your doctor is considering prescribing Ethionamide (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Never stop or change either medication without first consulting your healthcare provider