Why does cyclosporine lead to hyperkalemia, and what education should be provided to patients?

• A. Direct effect on the renin-angiotensin-aldosterone system and renal potassium excretion; educate on dietary potassium and regular potassium monitoring.
• B. Indirect effect via increased potassium loss in urine; educate to avoid potassium.
• C. It has no impact on potassium homeostasis; no education needed.
• D. It only affects sodium handling; advise no potassium restrictions.

Answer: (A)

Cyclosporine raises potassium mainly because it interferes with the kidney’s ability to excrete potassium, through effects on both renal hemodynamics and the hormonal control of potassium handling. By causing afferent arteriolar vasoconstriction and lowering glomerular filtration, it reduces the filtered load and secretion of potassium. It can also disrupt aldosterone action in the distal nephron, further decreasing potassium secretion. The net result is hyperkalemia risk, so education should focus on monitoring potassium and kidney function regularly, and managing potassium intake. Patients should follow any advised dietary potassium limits, avoid potassium-containing salt substitutes or potassium-sparing medications unless a clinician approves, and promptly report symptoms of high potassium (e.g., muscle weakness, tingling, fatigue, palpitations). They should also discuss with their clinician any other drugs that can raise potassium (like ACE inhibitors or ARBs) and keep up with lab tests and hydration as advised.