What term describes an undesirable effect of a medication that can cause minimal discomfort?

The term that best describes an undesirable effect of a medication that can cause minimal discomfort is "side effect." Side effects are typically secondary effects that occur alongside the expected therapeutic effects of a medication. They can range from mild to severe, but in this context, the emphasis is on the minimal discomfort that side effects often involve. For instance, a medication for allergies might cause drowsiness, which is an unwanted effect but usually not serious.

In contrast, adverse reactions are generally more severe and may require medical intervention. Complications refer to additional problems that arise as a result of a treatment or condition, typically indicating a more significant issue. Drug interactions occur when two or more substances affect each other’s actions, leading to unexpected effects, which may not necessarily relate to the medication's desired effects. Thus, side effects most accurately capture the idea of causing minimal discomfort as an undesirable response to medication.