Which term describes the delivery of a drug to the site of action by the bloodstream or lymphatic system?

Which term describes the delivery of a drug to the site of action by the bloodstream or lymphatic system?

• A. Excretion
• B. Metabolism
• C. Absorption
• D. Distribution

Answer: (D)

The main idea is how a drug gets from the bloodstream to the tissues where it can act. Delivering a drug to its site of action through the bloodstream (and, for some agents, via the lymphatic system) is called distribution. Once absorbed, the drug is carried by blood to various organs and tissues, and sometimes the lymphatics help move certain larger or lipid-rich molecules to distant sites. Distribution depends on factors like blood flow to tissues, how easily the drug crosses capillary walls, how it binds to plasma proteins or tissue components, and its chemical properties such as lipophilicity and size. In contrast, absorption is about entry into the bloodstream from the administration site, metabolism is the chemical modification of the drug (often in the liver), and excretion is its elimination. So distribution is the process that best fits the description.

The main idea is how a drug gets from the bloodstream to the tissues where it can act. Delivering a drug to its site of action through the bloodstream (and, for some agents, via the lymphatic system) is called distribution. Once absorbed, the drug is carried by blood to various organs and tissues, and sometimes the lymphatics help move certain larger or lipid-rich molecules to distant sites. Distribution depends on factors like blood flow to tissues, how easily the drug crosses capillary walls, how it binds to plasma proteins or tissue components, and its chemical properties such as lipophilicity and size. In contrast, absorption is about entry into the bloodstream from the administration site, metabolism is the chemical modification of the drug (often in the liver), and excretion is its elimination. So distribution is the process that best fits the description.