What are undesirable effects that can occur from medication usage known as?

The term that refers to undesirable effects that can occur from medication usage is "adverse reactions." Adverse reactions encompass a range of harmful or unintended responses to a medication, which can vary greatly in severity and duration. These reactions are a crucial aspect of pharmacology, as they can affect patient safety and treatment outcomes.

While side effects are also related to medication use, they typically denote the more predictable and often minor effects that occur alongside the desired therapeutic effects. In contrast, adverse reactions may include more serious health issues that require medical attention and differ significantly from the expected outcomes of using a drug.

Complications refer to secondary problems that may arise as a result of a disease or treatment, not necessarily tied to the medication itself, while contraindications are specific scenarios in which a medication should not be used due to the potential for harm. Understanding these distinctions is important in providing safe and effective patient care.