Louie, who is to receive a blood transfusion asks the nurse what is the most common type of infection he could receive from the transfusion. The nurse teaches him that approximately 1 in 250,000 patients contract:

Correct Answer: B

Rationale: Hepatitis C infection is the most common transfusion-transmitted infection, with an estimated risk of 1 in 250,000 units of blood. While the risk of HIV and hepatitis B has significantly decreased due to improved screening and testing, hepatitis C remains a concern. West Nile virus is rare and region-specific. The nurse should reassure Louie that the blood supply is rigorously tested, but hepatitis C is the most likely infection, albeit still rare.

Correct Answer: A

Rationale: Aging reduces creatinine clearance in about two-thirds of individuals due to declining renal function, a true statement impacting drug excretion. Body fat increases, not decreases, with age, altering distribution of lipophilic drugs, so that's false. Total body water decreases, not increases, affecting hydrophilic drugs. Conjugation (phase II) is less affected than oxidation (phase I) by age, making that false. Absorption isn't significantly altered by age alone. Reduced renal clearance is a critical age-related change, necessitating dose adjustments for renally cleared drugs like digoxin.

Correct Answer: A

Rationale: Sildenafil (Viagra) commonly causes nasal congestion due to vasodilation affecting nasal blood vessels, a frequent adverse effect tied to its mechanism. Earache isn't a recognized side effect-sildenafil targets vascular smooth muscle, not auditory systems. Blurry vision occurs from PDE-6 inhibition in the retina, another known issue. Priapism, a sustained erection, is a rare but serious risk requiring urgent care. Nasal congestion stands out as a typical, manageable effect, reflecting sildenafil's systemic vasodilatory impact, distinct from less common visual or emergent issues, and aligns with patient reports needing monitoring.

Correct Answer: C

Rationale: In the context of pharmacology and drug absorption, the correct answer to the question is C) diffusion. Diffusion is the passive movement of a substance from an area of higher concentration to an area of lower concentration, without the need for energy input. When a drug is ingested, it needs to cross membranes to enter the bloodstream and reach its target site in the body. This movement occurs via simple diffusion due to the concentration gradient. Option A) active transport is incorrect because active transport requires energy to move molecules against their concentration gradient, which is not the case in this scenario. Option B) osmosis is the movement of water across a semi-permeable membrane, not drug molecules. Option D) metabolism refers to the chemical processes that occur within a living organism to maintain life, and it is not directly related to the movement of a drug across membranes. Understanding the concept of diffusion is crucial in pharmacology as it influences how drugs are absorbed, distributed, metabolized, and excreted in the body. By grasping this fundamental process, healthcare professionals can better comprehend drug actions, dosing regimens, and potential interactions, leading to improved patient outcomes.

Correct Answer: A

Rationale: Persistent insomnia despite meds suggests a primary disorder like sleep apnea-e.g., obstructed breathing disrupts sleep-needing assessment (e.g., EEG), not just med failure. Selling meds lacks evidence. Addiction or personality disorders don't explain resistance. Sleep apnea fits chronicity, per sleep science.