How would lower cardiac output affect subcutaneous administration?

How would lower cardiac output affect subcutaneous administration?

• A. Slower absorption because blood flow is slower, reducing gradient
• B. Faster absorption due to slower clearance
• C. No effect
• D. Absorption becomes unpredictable

Answer: (A)

Subcutaneous absorption is largely governed by local blood flow. After injection, the drug must diffuse into nearby capillaries and then be carried away by the bloodstream. If cardiac output is reduced, peripheral blood flow drops, so the drug is removed from the injection site more slowly. This slows the rate at which the drug enters systemic circulation, leading to slower absorption and a delayed onset. The total amount absorbed may still be similar, but the timing is longer. The other ideas don’t fit the mechanism: faster absorption would require higher perfusion; no effect ignores the perfusion dependency; and unpredictable absorption isn’t the typical outcome of reduced cardiac output, which more predictably slows absorption.

Subcutaneous absorption is largely governed by local blood flow. After injection, the drug must diffuse into nearby capillaries and then be carried away by the bloodstream. If cardiac output is reduced, peripheral blood flow drops, so the drug is removed from the injection site more slowly. This slows the rate at which the drug enters systemic circulation, leading to slower absorption and a delayed onset. The total amount absorbed may still be similar, but the timing is longer. The other ideas don’t fit the mechanism: faster absorption would require higher perfusion; no effect ignores the perfusion dependency; and unpredictable absorption isn’t the typical outcome of reduced cardiac output, which more predictably slows absorption.