CNN Pharmacology Practice Questions (160 Flashcards)

The ESA dose should be reduced or interrupted. NNCC exams emphasize that Hb levels should generally not exceed 11 g/dL in CKD patients on ESAs due to increased risks of stroke, venous thromboembolism, and cardiovascular events (Trial to Reduce Cardiovascular Events with Aranesp Therapy [TREAT] data). A rise in Hb >1 g/dL in any 2-week period is a trigger for dose reduction (typically by 25%). **Exam Strategy:** Watch for distractors suggesting continue current dose if the patient feels better. The Black Box Warning for ESAs is a high-yield topic; always prioritize safety over reaching higher normal Hb levels.

Phosphate binders must be taken with every meal and snack containing phosphorus to be effective. Their mechanism requires direct contact with food in the stomach/duodenum to bind dietary phosphorus before absorption. Taking them once daily leaves phosphorus from other meals unsequestered. Education: Nurses should emphasize No food, no binder. Exam Tip: NNCC often tests the timing of binders—they should be taken within 10-15 minutes of eating for maximum efficacy.

SGLT2 inhibitors reduce the metabolic workload of the proximal tubule by inhibiting the energy-intensive active transport of glucose and sodium. This reduces tubular oxygen consumption and alleviates cortical hypoxia. Improved oxygenation in the renal interstitium may also stimulate erythropoietin production, potentially explaining the slight increase in hematocrit often seen in these patients.

Sterile (Aseptic) Peritonitis or Icodextrin-induced hypersensitivity. This is a rare immune-mediated reaction to the glucose polymers or contaminants (like peptidoglycans). Clinical Action: Differentiate from infectious peritonitis (which usually presents with $>100$ WBC/mm3 and $>50\%$ neutrophils). Sterile peritonitis typically resolves upon discontinuation of Icodextrin. Exam focus: Note the presence of eosinophils and the lack of clinical symptoms (no pain).

Cyclosporine inhibits the Multidrug Resistance-associated Protein 2 (MRP2) transporter on the biliary membrane. This prevents the excretion of Mycophenolic Acid Glucuronide (MPAG) into the bile, thereby blocking the enterohepatic recirculation of Mycophenolic Acid (MPA). Exam Strategy: Switching a patient from Cyclosporine to Tacrolimus (which does not inhibit MRP2) will result in a significant INCREASE in MPA levels, potentially leading to GI toxicity or leukopenia. Nurses must monitor CBC and GI symptoms closely during this transition.