How is Tc HDP and Tc MDP typically administered?

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

Answer: (C)

Tc HDP (technetium-99m hydroxymethylidene diphosphonate) and Tc MDP (technetium-99m medronic acid diphosphonate) are commonly administered intravenously due to their nature as radiopharmaceuticals designed for imaging purposes. The intravenous route allows for rapid distribution within the bloodstream and facilitates effective targeting of bone tissue, which is crucial for achieving optimal imaging results in nuclear medicine studies.

Administering these compounds intravenously ensures that they quickly travel to the areas of interest within the body, allowing for real-time imaging and accurate assessments of bone metabolism and pathology. This method maximizes the bioavailability of the radiopharmaceuticals and improves the resolution of the imaging captured by the gamma camera during bone scans.

In contrast, the other routes listed—oral, intramuscular, and subcutaneous—are less suitable for this type of radiopharmaceutical. Oral administration would lead to significant first-pass metabolism, reducing the effectiveness of the imaging agents. Intramuscular injections might not provide adequate circulation of the agent in the bloodstream, while subcutaneous administration could result in limited absorption and variability in the distribution of the compound throughout the body. Hence, the intravenous route is the optimal choice for administering Tc HD