How is Tc exametazime (HMPAO) administered?

• A. Orally
• B. Intramuscularly
• C. Intravenously
• D. Subcutaneously

Answer: (C)

Tc exametazime, commonly known as HMPAO (hexamethylpropyleneamine oxime), is administered intravenously. This method of administration ensures that the radiopharmaceutical is delivered directly into the bloodstream, allowing for immediate circulation to the tissues and organs, which is essential for accurate imaging. The intravenous route is preferred particularly for radiopharmaceuticals like HMPAO as it provides a rapid onset of action and effective distribution, which is critical in nuclear medicine procedures such as brain scans or perfusion studies.

Oral administration is typically less effective for compounds that are meant to be rapidly distributed in the body, as they need to pass through the gastrointestinal tract before entering systemic circulation. Intramuscular and subcutaneous routes are also less suitable for radiopharmaceuticals intended for imaging since they can lead to slower absorption and delayed imaging results. In contrast, intravenous administration ensures that the diagnostic agent reaches the target organs effectively and provides high-quality imaging results.