A nurse is teaching a class about pharmacodynamics.The nurse should include that which of the following medication levels occurs when a medication is at the lowest serum concentration?

Choice A rationale

Anticholinergics/antispasmodics can cause constipation by reducing the muscle contractions of the gastrointestinal tract, leading to slower movement of contents and resulting in constipation.

Choice B rationale

Opioid narcotics cause constipation by binding to opioid receptors in the gastrointestinal tract, which decreases intestinal motility and inhibits the secretion of fluids, leading to hard and dry stools.

Choice C rationale

Iron supplements can cause constipation as a common side effect due to their effect on the gastrointestinal tract. They can make stools harder and more difficult to pass.

Choice D rationale

Magnesium-containing antacids typically do not cause constipation. In fact, they are more likely to have a laxative effect due to the presence of magnesium, which can increase water in the intestines and soften stools.

Choice A rationale

Replacing the external urinary catheter once each day is unnecessary. The catheter should be changed based on clinical judgment and manufacturer's guidelines to maintain hygiene.

Choice B rationale

Inserting the catheter into the client's urethra is incorrect for an external urinary catheter. External catheters are designed to be placed outside the body.

Choice C rationale

Applying a barrier cream to the client's perineal skin is correct. Barrier creams protect the skin from moisture and prevent skin breakdown and irritation caused by urine.

Choice D rationale

Connecting the catheter to continuous wall suction is not appropriate. External urinary catheters should be connected to a drainage bag for proper urine collection. .