A patient claims to get better effects with a tablet of Brand X of a drug than with a tablet of Brand Y of the same drug. Both brands contain the same amount of the active ingredient. What does the nurse know to be most likely?

Question

a. Advertising by pharmaceutical companies can enhance patient expectations of one brand over another, leading to a placebo effect.
b. Because the drug preparations are chemi-cally equivalent, the effects of the two brands must be identical.
c. Tablets can differ in composition and can have differing rates of disintegration and dissolution, which can alter the drug's ef-fects in the body.
d. The bioavailability of a drug is determined by the amount of the drug in each dose.

Answer 1

C
Even if two brands of a drug are chemically equivalent (i.e., they have identical amounts of the same chemical compound), they can have different effects in the body if they differ in bioavaila-bility. Tablets made by different manufacturers contain different binders and fillers, which disin-tegrate and dissolve at different rates and affect the bioavailability of the drug. Two brands may be chemically equivalent and still differ in bioavailability, which is not determined by the amount of drug in the dose.