A nurse is providing patient education to a 55-year-old man who has been prescribed opioids for chronic back pain. Which of the following statements by the nurse is most appropriate when educating the patient about opioid-induced constipation?

A. Dry Cough: A dry cough is not typically associated with salicylate toxicity. It is more commonly seen in conditions like ACE inhibitor use, respiratory infections, or asthma, and does not help distinguish salicylate overdose.
B. Xanthopsia (Yellow Vision): This visual disturbance is more classically linked to digoxin toxicity, not salicylates. Patients experiencing digoxin toxicity may report seeing halos or yellow-tinted vision, but this is not seen with aspirin overdose.
C. Moon Facies: This refers to a rounded facial appearance typically caused by chronic corticosteroid use and is a hallmark of Cushingoid features, not salicylate toxicity.
D. Tinnitus: Ringing in the ears (tinnitus) is a classic early symptom of salicylate toxicity. It often precedes more serious effects like metabolic acidosis, hyperventilation, confusion, and even seizures. It serves as an important clinical clue when assessing patients with possible aspirin overdose.

A. Drugs with strong first-pass metabolism are best administered via an enteral route: Drugs that undergo extensive first-pass metabolism are often less effective when given enterally, as much of the drug is inactivated by the liver before reaching systemic circulation. Non-enteral routes (e.g., sublingual, IV) are preferred to bypass the liver initially.
B. Metabolism alters medications so that they can be excreted from the body: The liver uses enzymatic processes to convert drugs into more water-soluble forms, facilitating their elimination through the kidneys or bile. This process can either activate, inactivate, or detoxify substances depending on the drug.
C. The first-pass effect increases the bioavailability of orally administered drugs: The first-pass effect reduces, not increases, the bioavailability of orally administered drugs. It refers to the initial metabolism in the liver that significantly reduces the active concentration of a drug before it reaches systemic circulation.
D. Metabolism primarily occurs in the kidneys: While the kidneys are essential for drug excretion, metabolism primarily occurs in the liver. Hepatic enzymes, especially those of the cytochrome P-450 system, play the central role in drug biotransformation.