Which of the following drugs is known to lower blood tagging efficiency?

Digoxin is well recognized for its influence on cardiac function, primarily through its ability to increase the force of myocardial contractions and regulate heart rate. In the context of blood tagging efficiency, particularly in nuclear medicine and radiopharmacy practices, the primary concern with digoxin is its potential to affect the uptake and distribution of radiopharmaceuticals used in imaging studies.

When radiopharmaceuticals are injected, they are tagged to specific biological markers in the body, and the efficiency of this tagging can be influenced by various factors, including the pharmacological effects of medications. Digoxin, as a cardiac glycoside, can alter hemodynamic parameters like heart rate and stroke volume, which may in turn impact the distribution and clearance of radiotracers in the bloodstream. This alteration may lead to a decrease in tagging efficiency when assessing cardiac function or other organ-specific imaging.

In contrast, the other medications listed—amiodarone, lisinopril, and metformin—typically do not have the same direct effects on the tagging efficiency of radiopharmaceuticals. Amiodarone is primarily an antiarrhythmic agent that may have complex interactions with iodine and imaging studies but does not specifically lower tagging efficiency. Lisinopril, an ACE