Adverse effects of iodine thyroid blocking: a systematic review

Area of Science:

• Radiological health
• Pharmacoepidemiology
• Thyroid disease prevention

Background:

• Radioactive iodine ((131)I) exposure, such as from nuclear accidents, increases thyroid cancer risk.
• Iodine thyroid blocking (ITB) is a public health measure to mitigate this risk.
• Systematic investigation of ITB's adverse effects is lacking.

Purpose of the Study:

• To systematically review and summarize the available literature on adverse effects of iodine thyroid blocking (ITB).
• To assess the evidence base for adverse reactions to ITB in the general population.

Main Methods:

• A systematic literature search was conducted in scientific medical databases.
• 14 relevant articles were identified, including surveys, ecological, and intervention studies.
• A meta-analysis was not feasible due to significant study heterogeneity.

Main Results:

• The reviewed studies did not report severe adverse reactions to potassium iodide in the general public.
• Evidence on adverse effects is largely indirect, relying on studies of iodine administration in different contexts.
• Only one study specifically examined ITB effects post-Chernobyl accident.

Conclusions:

• Scientifically sound studies on ITB adverse effects are scarce, resulting in a weak evidence base.
• Current evidence suggests minimal severe adverse reactions to ITB in the general population.
• Further pharmacoepidemiological research is needed to better quantify ITB's safety profile.