What term refers to the change in effectiveness of two or more substances when used in combination?

The term that refers to the change in effectiveness of two or more substances when used in combination is known as potentiation. Potentiation occurs when one substance enhances the effect of another, leading to a combined effect that is greater than the sum of their individual effects. This phenomenon is particularly relevant in pharmacology and can occur with medications, where one drug may enhance the therapeutic effect or side effects of another, demonstrating the importance of understanding drug interactions in gerontology and elderly care.

In this context, recognizing potentiation is crucial for healthcare providers when prescribing medications to older adults, as they may be more sensitive to the effects of drugs and their interactions. Understanding this term helps professionals ensure safe and effective treatment plans that account for the complexities of medication management in older populations.