What does toxicity occur?

Toxicity occurs when the peak blood level of the drug is too high. This condition arises because many medications have a therapeutic range, which is the concentration of the drug in the bloodstream that is effective without being harmful. When drug levels exceed this therapeutic range, it can lead to adverse effects and potential harm to the patient. High concentrations can overwhelm the body's ability to metabolize or excrete the medication, resulting in the manifestation of toxic effects. Understanding peak levels is crucial for ensuring safe medication administration and avoiding toxic reactions.

The other options pertain to different scenarios that may affect drug efficacy or safety but do not directly define the mechanism of toxicity as accurately as the selected answer. Administering drugs too frequently or giving incorrect dosages may lead to elevated drug levels, but it is the peak blood level specifically that determines toxicity. Improper absorption can affect drug effectiveness but does not directly correlate with reaching toxic levels in the bloodstream.