Which of the following conditions could contribute to an increase in unbound drug concentration in the blood?

An increase in unbound drug concentration in the blood can occur due to a variety of physiological changes that affect drug binding to proteins, particularly albumin. Chronic renal failure significantly contributes to this increase in unbound drug concentration for several reasons.

In kidney failure, the ability to excrete drugs is impaired, leading to a reduced clearance of drugs from the bloodstream. When renal function declines, there can also be a decrease in the synthesis of important plasma proteins, including albumin. Lower levels of albumin result in less protein available to bind to drugs, which can lead to a higher concentration of free (unbound) drug in circulation. This is particularly important since only the unbound drug is pharmacologically active and can exert therapeutic effects or cause toxicity.

Chronic renal failure can also lead to an accumulation of uremic toxins that can displace drugs from their protein-binding sites, further increasing the levels of unbound drug in the system. Therefore, the condition of chronic renal failure is directly associated with an elevation in unbound drug concentration in the blood.

The other choices do not contribute to this increase. Overhydration may dilute plasma proteins but does not directly affect their binding capacity in a manner that increases unbound drug concentrations. Healthy liver function