Comparative Pharmacology
Head-to-head clinical analysis: SODIUM IODIDE I 123 versus SODIUM PHOSPHATE P 32.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SODIUM IODIDE I 123 versus SODIUM PHOSPHATE P 32.
SODIUM IODIDE I 123 vs SODIUM PHOSPHATE P 32
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sodium iodide I 123 is a radioactive isotope that emits gamma radiation. Following oral or intravenous administration, it is rapidly absorbed and selectively concentrated in the thyroid gland via the sodium-iodide symporter (NIS). The emitted gamma rays allow for imaging of thyroid tissue and detection of abnormal uptake patterns.
Sodium phosphate P 32 is a radioactive isotope that emits beta particles, causing ionization and subsequent cell death, particularly in rapidly dividing cells. It is incorporated into DNA and RNA, concentrating in tissues with high metabolic activity such as bone marrow and neoplastic cells.
Oral: 400-800 μCi (14.8-29.6 MBq) for thyroid uptake studies; 150-300 μCi (5.6-11.1 MBq) for thyroid scan. Administer orally as a single dose.
Intravenous administration: 1.5 mCi (55.5 MBq) per 70 kg body weight, single dose. For polycythemia vera, oral dose: 3-5 mCi (111-185 MBq) as a single dose. Frequency is one-time or as needed based on response.
None Documented
None Documented
13.2 hours (physical T1/2); effective T1/2 ~13 hours in euthyroid; prolonged in hypothyroidism.
Terminal elimination half-life: 14.3 days (range 13-16 days). Clinically relevant for bone marrow suppression monitoring; cumulative effect over multiple doses.
Primarily renal (90%) as iodide; small amount feces (<5%) and negligible biliary.
Renal: ~40% within 24 hours via glomerular filtration; Fecal: ~60% over 1-2 weeks as unabsorbed or secreted into bile. Total elimination approaches 100% after 2 weeks.
Category C
Category C
Radiopharmaceutical
Radiopharmaceutical