When radioactive iodine is released, as after the Chernobyl disaster, it can be absorbed into the human thyroid gland. Potassium iodide can be taken to block this uptake.
Parameters:
(1) age of the patient
(2) if female, pregnancy or lactation
(3) predicted thyroid exposure in centigrays (cGy) I131 (where 1 cGy = 1 rem)
Population |
Age Range |
Exposure in cGy |
Dose of Potassium Iodide in mg |
adult |
> 40 |
>= 500 |
130 |
adult |
> 18 and <= 40 |
>= 10 |
130 |
woman who is pregnant or lactating |
any |
>= 5 |
130 |
adolescent, adult sized (>= 70 kg) |
> 12 and <= 18 |
>= 5 |
130 |
adolescent |
> 12 and <= 18 |
>= 5 |
65 |
child |
> 3 and <= 12 |
>= 5 |
65 |
infant and young child |
> 1 month to 3 years |
>= 5 |
32 |
neonate |
birth to 1 month |
>= 5 |
16 |
where:
• According to the footnote on page 2, the radiation emitted by I131 (photons and electrons) has radiation-weighting factor of 1. The absorbed dose to the thyroid gland expressed in centigrays (cGy) is "numerically equal to the thyroid equivalent dose expressed in rem (1 cGy = 1 rem)."
Additional guidance:
(1) The protective effect of potassium iodide lasts about 24 hours. Daily dosing is required until the risk of exposure to a radioactive iodine no longer exists.
(2) Priority in dosing and protective measures should be given to persons intolerant to potassium iodide, pregnant or lactating women and neonates.
Purpose: To treat a patient exposed to radioactive iodine during a radiation emergency using potassium iodide as a blocking agent.
Specialty: Hematology Oncology
Objective: dosage calculations
ICD-10: T66,