Clinical Nurse Specialist Advanced Pharmacology

Question 1

A 70-year-old patient on warfarin for atrial fibrillation is admitted for pneumonia. The patient develops QTc prolongation (QTc 520 ms) on the cardiac monitor. Which antibiotic should the CNS recognize as most likely contributing to QT prolongation?

Accepted Answer

Azithromycin

Answer

Azithromycin (and fluoroquinolones) are well-documented QT-prolonging antibiotics — macrolides inhibit cardiac hERG potassium channels, prolonging ventricular repolarization.

Question 2

A patient with severe sepsis requires vasopressor support. Norepinephrine has been initiated. The intensivist is considering adding vasopressin. What is the primary pharmacological rationale for vasopressin use in septic shock?

Accepted Answer

Vasopressin acts on V1 receptors independently of adrenergic receptors, compensating for relative vasopressin deficiency in septic shock

Answer

Vasopressin acts on V1 (vascular) receptors to cause vasoconstriction independently of adrenergic signaling, compensating for the relative vasopressin deficiency seen in prolonged septic shock.

Question 3

A 65-year-old patient with CKD stage 4 (GFR 22 mL/min) requires pain management after total knee replacement. Which opioid selection and dosing consideration is most appropriate?

Accepted Answer

Hydromorphone at reduced doses with extended dosing intervals is safer than morphine in significant renal impairment

Answer

Hydromorphone is preferred over morphine in renal impairment; morphine's active metabolite (M6G) accumulates in renal failure causing CNS/respiratory depression.

Question 4

A patient on chronic prednisone 20 mg daily for rheumatoid arthritis requires emergency appendectomy. What is the critical perioperative pharmacological concern?

Accepted Answer

Hypothalamic-pituitary-adrenal (HPA) axis suppression requiring stress-dose steroids

Answer

Chronic glucocorticoid use suppresses the HPA axis; surgical stress requires cortisol surge that suppressed adrenal glands cannot produce — stress-dose steroids prevent adrenal crisis.

Question 5

A CNS reviewing a patient's medication list notes the patient takes simvastatin 80 mg and has been newly prescribed clarithromycin for H. pylori. What is the critical drug interaction concern?

Accepted Answer

Clarithromycin inhibits CYP3A4, dramatically increasing simvastatin levels and risk of rhabdomyolysis

Answer

Clarithromycin is a potent CYP3A4 inhibitor; simvastatin is a CYP3A4 substrate — co-administration dramatically increases simvastatin AUC (up to 10-fold), causing severe rhabdomyolysis risk.

Clinical Nurse Specialist Practice Test

Clinical Nurse Specialist Practice Test

Clinical Nurse Specialist Advanced Pharmacology