In medical coding, what does the term 'adverse effect' refer to?

The term 'adverse effect' refers to any harmful or unintended reaction that occurs as a result of taking a medication. These effects can range from mild to severe and are not limited to allergic reactions. In the context of the choices provided, an allergic reaction to a drug certainly falls under the category of adverse effects since it is an undesirable response to the medication.

Other options present scenarios that do not align with the definition of an adverse effect. Drug abuse pertains to the misuse of substances, while proper medication administration refers to giving the correct dosage and method without unintended consequences. The effectiveness of medications, on the other hand, indicates a positive outcome rather than an adverse effect. Thus, the identification of an allergic reaction as an adverse effect is accurate, as it highlights the potential harm caused by medications.