A client with benign prostatic hyperplasia is to receive finasteride (Proscar). The nurse understands that this drug works by

Correct Answer: B

Rationale: Finasteride (Proscar), a 5-alpha reductase inhibitor, shrinks the prostate in BPH by reducing dihydrotestosterone, easing urinary obstruction. Smooth muscle relaxation is for ED drugs like sildenafil. It lowers DHT, not testosterone, and doesn't stimulate RNA synthesis. Prostate shrinkage is its core action, distinct from other mechanisms.

Correct Answer: C

Rationale: Neonates have an immature blood-brain barrier, increasing opioid penetration, not blocking it, so that's false. Spinal analgesia involves mu, delta, and kappa receptors, not just one type, making that false. Depressed CO2 response is the most reliable sign of opioid-induced respiratory depression, a true statement, reflecting medullary suppression. Tolerance to miosis develops minimally, unlike analgesia, so that's false. Addison's patients are hypersensitive to opioids due to cortisol lack. The CO2 response is a key monitoring parameter in opioid overdose.

Correct Answer: D

Rationale: Morphine undergoes extensive first-pass metabolism in the liver, which reduces its oral bioavailability significantly.

Correct Answer: A

Rationale: Imipramine, a tricyclic antidepressant, is highly cardiotoxic in overdose, often causing fatal dysrhythmias due to sodium channel blockade, leading to widened QRS complexes and ventricular arrhythmias. The priority assessment must focus on cardiac status to detect life-threatening changes like tachycardia or arrhythmias, requiring immediate intervention such as sodium bicarbonate or cardioversion. Liver function and renal status may be affected long-term but aren't the acute priority in overdose. Neurological function , while impacted (e.g., seizures), is secondary to cardiac risks, as circulatory collapse poses the greatest immediate threat. The nurse's focus on cardiac monitoring aligns with toxicology protocols, ensuring rapid response to the most lethal complication, making choice A the critical assessment in this emergency scenario.

Correct Answer: C

Rationale: Oseltamivir treats influenza by inhibiting neuraminidase . This prevents viral release from infected cells, reducing spread. M2 blockade is amantadine's action. IMP dehydrogenase , reverse transcriptase , and DNA polymerase (E) are unrelated. Neuraminidase inhibition shortens his illness.