Dobutamine:

Correct Answer: D

Rationale: Dobutamine, a β1-selective agonist, can cause arrhythmias, so no arrhythmogenic effect is false. It increases myocardial oxygen consumption by enhancing contractility, not decreases it. It's selective, not non-selective, targeting cardiac β1 receptors. It doesn't act on CNS D2 dopamine receptors but on peripheral β1. It's used in heart failure to boost cardiac output, a true statement, making it valuable in acute settings. This inotropic effect distinguishes it from non-selective agents, critical for managing cardiogenic shock.

Correct Answer: B

Rationale: Biliary secretion (e.g., rifampin) leads to fecal excretion for some drugs, while others recycle enterohepatically, prolonging action. Not all are fecal-bound-recirculation varies. Gallbladder stores bile, not metabolizes. Many drugs use bile, not rare. Recirculation reflects pharmacokinetics, affecting duration.

Correct Answer: B

Rationale: Buspirone requires regular dosing-weeks-to reduce anxiety via serotonin modulation, not PRN like benzos, per pharmacology. Dizziness, headache, drowsiness are true side effects. Regular use is needed for effect. It's non-addictive, unlike benzos. PRN use misstates its action, needing correction.

Correct Answer: D

Rationale: Hypocalcemia causes muscle spasms (tetany)-nerve hyperexcitability, per classic signs-unlike bruising (coagulation), hypertension (not direct), or wasting (chronic). Spasms dominate, per assessment.

Correct Answer: A

Rationale: Pregnancy and a porcine valve increase thromboembolism risk. Heparin , an anticoagulant, is safe in pregnancy. Streptokinase , a thrombolytic, is risky. TED stockings prevent but don't treat systemic risk. Warfarin is teratogenic. Heparin's non-placental crossing ensures fetal safety while managing her condition.