The nurse is caring for an older adult patient who is receiving multiple medications. When monitoring this patient for potential drug toxicity, the nurse should review which lab values closely?

A. Bioavailability refers to the proportion of a drug that enters systemic circulation and is available for therapeutic effect. Generic drugs must demonstrate bioequivalence to brand-name drugs, meaning their bioavailability must be within an acceptable range to ensure similar efficacy.

B. Critical concentration is the minimum drug level required to produce a therapeutic effect, but it is not the primary factor in generic drug substitution.

C. Distribution refers to how a drug is transported in the body after absorption, but it is not the main concern when substituting generic drugs.

D. Half-life is the time required for the drug concentration to decrease by half in the body, but it does not determine whether a generic drug can replace a brand-name drug. Bioavailability is the key factor in ensuring therapeutic equivalence.

a) Applying the medication liberally is incorrect because the amount of medication applied should be based on the prescribed dose. Overapplication can lead to excessive absorption and potential systemic effects.

b) Cleaning the skin with alcohol before applying the medication is not always necessary and can cause irritation. Some medications require specific preparation, but alcohol is not a universal requirement.

c) Using sterile technique is generally unnecessary for topical medication application unless the skin is broken or there is an open wound requiring sterility.

d) Wearing gloves is essential to prevent medication absorption through the nurse’s skin and to reduce the risk of contamination or infection.