Why should salt substitutes be avoided in patients taking diuretics?

• A. They contain calcium which interferes with diuretic action
• B. Salt substitutes that contain potassium may cause hyperkalemia with life threatening consequences
• C. They contain sodium which reduces diuretic efficiency
• D. They are recommended for patients on diuretics

Answer: (B)

Potassium-containing salt substitutes raise the amount of potassium in the body. Many substitutes use potassium chloride instead of sodium chloride, so adding them to the diet can push serum potassium higher. In patients on diuretics, potassium handling can be unstable, and this risk is amplified if kidney function is reduced or if other medications that conserve potassium are involved. Hyperkalemia can disrupt cardiac conduction and lead to life-threatening arrhythmias, so using potassium-rich salt substitutes with diuretics is avoided to prevent these dangerous outcomes.