Statement C is NOT True: Loop Diuretics DO Cause Hypokalemia
Loop diuretics are a well-established cause of hypokalemia and are explicitly listed as causing hypokalaemia in multiple heart failure guidelines 1, 2. This makes statement C false.
Analysis of Each Statement
Statement A: Inadequate Dietary Intake Alone Can Cause Hypokalemia
TRUE. While less common than other causes, inadequate dietary intake alone can cause hypokalemia, though it typically requires prolonged severe restriction 3, 4. The World Health Organization recommends at least 3,510 mg of potassium daily for optimal cardiovascular health 3.
Statement B: Severe Hypokalemia Causes Serious Arrhythmias and Rhabdomyolysis
TRUE. This is well-documented in the literature:
- Severe hypokalemia (≤2.5 mEq/L) can cause life-threatening cardiac arrhythmias, particularly in patients on digitalis therapy 5, 6, 3
- Muscle necrosis (rhabdomyolysis), paralysis, and impaired respiration can occur with very low potassium levels 3, 7
- Hypokalemia increases mortality risk up to 10-fold in cardiovascular patients 8
Statement C: Loop Diuretics Do Not Cause Hypokalemia
FALSE - THIS IS THE INCORRECT STATEMENT. The evidence is unequivocal:
- European Heart Failure guidelines explicitly list "hypokalaemia" as a major side effect of loop diuretics (furosemide, bumetanide, torasemide) 2
- ACC/AHA guidelines state that "diuretics can cause the depletion of important cations (potassium and magnesium)" 5, 6
- Loop diuretics promote kaliuresis through the NKCC transporter in the loop of Henle 9
- Recent data shows loop diuretic use is an independent predictor of hypokalemia (OR = 2.10, p = 0.023) 10
Statement D: GI Loss from Infectious Diarrhea is the Most Common Cause in Developing Countries
TRUE. While the provided guidelines focus primarily on developed countries and heart failure populations, gastrointestinal losses from infectious diarrhea are recognized as a major cause of hypokalemia globally, particularly in developing countries where infectious diarrhea is endemic 3.
Statement E: Insulin and Beta-Agonists Increase Intracellular Potassium
TRUE. Both insulin and beta-adrenergic agonists cause transcellular shifts of potassium INTO cells, temporarily lowering serum potassium 3, 8. This mechanism is actually used therapeutically in acute hyperkalemia treatment 3, 11.
Clinical Relevance for This Patient
This 80-year-old man with heart failure and severe hypokalemia (2.6 mmol/L) likely has diuretic-induced hypokalemia, given his heart failure diagnosis. The guidelines recommend:
- Urgent treatment is needed as his potassium is ≤2.5 mEq/L 3, 11
- Potassium-sparing diuretics (spironolactone, amiloride, or triamterene) should be added if hypokalaemia persists despite ACE inhibitor therapy 1, 2
- Monitor closely for arrhythmias, especially if on digoxin 2, 5
- Target potassium should be maintained at 4.5-5.0 mEq/L in heart failure patients 12
- Oral potassium supplements are less effective than potassium-sparing diuretics for maintaining body potassium stores during diuretic treatment 2