What type of adverse reaction is related to elevated levels of drugs in the blood?

An overdose reaction is characterized by elevated levels of a drug in the bloodstream, which can lead to toxic effects on the body. When the concentration of a drug exceeds the therapeutic range, it can result in symptoms such as confusion, drowsiness, seizures, or respiratory distress, depending on the specific drug involved. This situation typically arises from administering a dose that is too high, whether due to an error in calculation, improper administration, or insufficient clearance of the drug from the body. Unlike allergic reactions, which are immune responses to allergens, or idiosyncratic reactions, which are unpredictable responses not related to the drug's pharmacological action, an overdose is directly linked to the quantifiable level of the drug present in the system. Therefore, recognizing an overdose reaction as linked to elevated drug levels emphasizes the importance of dosage accuracy and monitoring blood levels, particularly for anesthetic agents with narrow therapeutic indices.