What effect does fewer protein binding sites have on drug distribution in older adults?

Fewer protein binding sites in older adults lead to an increased concentration of free drug in the bloodstream. This is because many drugs are protein-bound, and when there are fewer available binding sites, a larger fraction of the drug remains unbound or "free." This free drug fraction is pharmacologically active and can exert its effects on the body.

As the free drug concentration rises, the potential for pharmacological effects increases, which may potentially enhance or lead to adverse reactions. Understanding this concept is particularly important in the context of older adults, who often experience changes in body composition, such as reduced muscle mass and altered protein levels, further impacting drug distribution and efficacy. The increased free drug concentration can therefore lead to heightened sensitivity to medications and a higher risk of side effects or toxicity, making careful monitoring and dosage adjustments essential in this population.