What might happen if a drug dose is given when the drug level is already high in the system?

When a drug dose is given while the drug level is already high in the system, cumulative effects can occur. This happens when the drug is either still being absorbed or not yet eliminated from the body. As a result, the additional dose adds to the existing concentration of the drug in the bloodstream, which can lead to a stronger or more prolonged effect than intended. Cumulative effects can be particularly concerning with medications that have a narrow therapeutic range, where small changes in dosage can lead to significant differences in response or toxicity.

High levels of a drug can also increase the risk of adverse reactions, as the body may not be able to metabolize and excrete it fast enough. This is a key reason why healthcare providers closely monitor drug levels, especially with medications that require careful dose management.