A nursing student asks how nonsteroidal anti-inflammatory drugs (NSAIDs) work to suppress inflammation and reduce pain. The nurse will explain that NSAIDs

A) Celecoxib (Celebrex):
Celecoxib is a selective COX-2 inhibitor that targets the cyclooxygenase-2 enzyme, which is primarily responsible for inflammation, pain, and fever. COX-2 inhibitors tend to cause less gastrointestinal irritation compared to nonselective NSAIDs like aspirin, which block both COX-1 and COX-2 enzymes. Because aspirin is causing gastrointestinal upset, switching to Celecoxib, which is less likely to irritate the stomach lining, may be an appropriate option to prevent myocardial infarction while minimizing gastrointestinal discomfort.

B) Enteric-coated aspirin:
Enteric-coated aspirin is designed to dissolve in the small intestine rather than the stomach, which may reduce some gastrointestinal irritation. However, it does not eliminate the risk entirely, and it still functions as a COX-1 inhibitor. If the patient is already experiencing gastrointestinal upset, simply switching to enteric-coated aspirin may not be sufficient to alleviate the discomfort, and other options should be considered.

C) Nabumetone (Relafen):
Nabumetone is a nonsteroidal anti-inflammatory drug (NSAID) with some COX-2 selectivity. While it may cause less gastrointestinal upset than non-selective NSAIDs like aspirin, it is still an NSAID and carries a risk of gastrointestinal side effects, especially with prolonged use.
D) A COX-2 inhibitor:
While COX-2 inhibitors, including Celecoxib, are typically effective in reducing inflammation and pain with fewer gastrointestinal side effects than traditional NSAIDs, the term "a COX-2 inhibitor" could refer to various drugs, and Celecoxib (Celebrex) is the most commonly used.

A) Proteins:
Proteins are generally too large to diffuse freely across the cell membrane. They require specific transport mechanisms, such as endocytosis or transport proteins, to move in and out of cells. The hydrophilic nature of most proteins further complicates their passage across the lipid bilayer.

B) Enzymes:
Like proteins, enzymes are large molecules that do not freely diffuse across cell membranes. Enzymes, being proteins, also need specialized transport mechanisms or need to be secreted or endocytosed to enter or exit cells.

C) Hormones:
Many hormones, particularly lipid-soluble ones like steroid hormones, can diffuse freely across the cell membrane. These hormones pass through the lipid bilayer due to their hydrophobic nature and bind to intracellular receptors, initiating cellular responses. However, water-soluble hormones (e.g., insulin) typically do not diffuse freely but interact with receptors on the cell surface.

D) Electrolytes:
Electrolytes (such as sodium, potassium, calcium, and chloride ions) are charged particles that cannot pass freely through the lipid bilayer due to the hydrophobic interior of the cell membrane. They require specific ion channels or transporters to move in and out of the cell. Diffusion of electrolytes is facilitated through these channels, but it is not a simple diffusion process as seen with small, uncharged molecules.