(12th Edition) Prep with Detailed Rationales
Course Code: NURS-302
Course Name: Lehne's Pharmacology for Nursing Care (12th Edition)
Topic: Ultimate Pathophysiological Approach Drug Guide
Academic Year: 2026/2027
1. A nurse is preparing to administer digoxin to a patient with chronic heart
failure. The patient’s current serum potassium level is 3.2 mEq/L. What is
the nurse's primary pathophysiological concern regarding this potassium
level?
A. Hypokalemia decreases digoxin binding sites, rendering the medication
ineffective.
B. Hypokalemia enhances digoxin binding to Na+/K+-ATPase,
significantly increasing the risk of digoxin toxicity.
C. Hyperkalemia promotes rapid renal clearance of the drug, leading to
therapeutic failure.
, D. Low potassium directly degrades the cardiac glycoside molecule in the
bloodstream.
CORRECT ANSWER: B
RATIONALE: Digoxin inhibits the Na+/K+-ATPase pump by
competing directly with potassium for binding sites. When a patient is
hypokalemic (<3.5 mEq/L), there is less competition for these sites,
allowing digoxin to bind more extensively. This amplifies its therapeutic and
toxic effects, predisposing the patient to life-threatening arrhythmias.
Distractors A, C, and D represent incorrect pharmacological mechanisms.
2. A patient with a deep vein thrombosis is prescribed warfarin. The nurse
monitors the patient’s International Normalized Ratio (INR). Which cellular
mechanism explains how warfarin exerts its anticoagulant effect?
A. Direct activation of antithrombin III to accelerate the degradation of
thrombin.
B. Inhibition of vitamin K epoxide reductase (VKORC1), preventing the
activation of vitamin K-dependent clotting factors (II, VII, IX, X).
C. Irreversible block of platelet cyclooxygenase-1 enzymes to limit
thromboxane A2.
D. Direct competitive binding to the active site of free and clot-bound
thrombin.
CORRECT ANSWER: B
RATIONALE: Warfarin acts by inhibiting vitamin K epoxide
reductase (VKORC1), an enzyme essential for recycling oxidized vitamin
K back into its reduced form. This depletion of reduced vitamin K prevents
the hepatic synthesis of functional clotting factors II, VII, IX, and X.
Distractor A describes heparin; distractor C describes aspirin; distractor D
describes direct thrombin inhibitors like dabigatran.
3. A patient in the emergency department presents with severe status
asthmaticus. The provider orders an immediate intravenous dose of
methylprednisolone. How do glucocorticoids fundamentally alter
pathophysiology to reverse severe airway inflammation?
A. Direct activation of beta-2 adrenergic receptors to induce immediate
smooth muscle relaxation.
B. Suppression of inflammatory gene transcription and inhibition of
, chemical mediators like leukotraines, prostaglandins, and histamine.
C. Direct chemical neutralization of airborne antigens within the alveolar
spaces.
D. Upregulation of muscarinic-3 receptors to promote rapid mucosal drying.
CORRECT ANSWER: B
RATIONALE: Glucocorticoids exert their anti-inflammatory effects by
binding to intracellular glucocorticoid receptors. This complex migrates to
the nucleus to decrease the transcription of pro-inflammatory cytokines and
enzymes (like COX-2), while decreasing the migration of eosinophils and
neutrophils. Distractor A describes short-acting beta agonists (SABAs);
distractors C and D mischaracterize steroid actions.
4. A patient with type 2 diabetes mellitus is prescribed metformin. What is the
primary mechanism of action by which metformin improves glycemic
control without triggering insulin-induced hypoglycemia?
A. Direct stimulation of pancreatic beta cells to increase basal insulin
secretion.
B. Inhibition of mitochondrial complex I, leading to decreased hepatic
gluconeogenesis and improved peripheral insulin sensitivity.
C. Competitive blockade of alpha-glucosidase enzymes within the brush
border of the small intestine.
D. Accelerated renal excretion of filtered glucose via the proximal
convoluted tubules.
CORRECT ANSWER: B
RATIONALE: Metformin lowers blood glucose primarily by
decreasing hepatic glucose production (gluconeogenesis) and increasing
insulin sensitivity in skeletal muscle. Because it does not stimulate
pancreatic insulin secretion, it does not cause hypoglycemia when used as
monotherapy. Distractor A describes sulfonylureas; distractor C describes
acarbose; distractor D describes SGLT2 inhibitors.
5. A patient undergoing chemotherapy for breast cancer is prescribed
filgrastim. The nurse educates the patient on the therapeutic target of this
medication. Which hematopoietic lineage is directly stimulated by this drug?
A. Erythroid progenitor cells to maximize mature red blood cell counts.
B. Megakaryocytes to increase systemic thrombocyte production.
, C. Granulocyte precursor cells to accelerate the production and
maturation of neutrophils.
D. Lymphoid stem cells to stimulate T and B lymphocyte proliferation.
CORRECT ANSWER: C
RATIONALE: Filgrastim is a granulocyte colony-stimulating factor
(G-CSF) produced by recombinant DNA technology. It binds to specific
surface receptors on hematopoietic cells, stimulating the proliferation,
differentiation, and functional activation of neutrophils to prevent
chemotherapy-induced neutropenia. Distractor A describes epoetin alfa;
distractor B describes oprelvekin; distractor D is not a target of G-CSF.
6. A nurse is reviewing the medication list for a patient with stage 4 chronic
kidney disease who requires treatment for hypertension. The nurse flags a
prescription for spironolactone. What is the primary pathophysiological risk
of administering this medication to this patient?
A. Severe dilutional hypernatremia due to fluid retention.
B. Profound hyperkalemia resulting from reduced renal excretion of
potassium in the distal nephron.
C. Rapid acceleration of renal osteodystrophy via calcium wasting.
D. Direct systemic vasoconstriction that worsens renovascular resistance.
CORRECT ANSWER: B
RATIONALE: Spironolactone is an aldosterone antagonist that blocks
mineralocorticoid receptors in the distal convoluted tubule and collecting
duct, leading to sodium excretion and potassium retention. In chronic
kidney disease, potassium excretion is already compromised. Combining
CKD with a potassium-sparing diuretic can precipitate life-threatening
hyperkalemia. Distractors A, C, and D are not adverse pathways associated
with spironolactone in renal impairment.
7. A patient with severe rheumatoid arthritis is starting therapy with
methotrexate. The nurse instructs the patient to take a prescribed daily
supplement of folic acid. What is the pharmacological rationale for this
intervention?
A. Folic acid accelerates the hepatic clearance of methotrexate to minimize
systemic sedation.
B. Folic acid replenishes essential cofactors to mitigate methotrexate-