• C03A Low-ceiling diuretics, thiazides 17 drugs
• C03B Low-ceiling diuretics, excl. thiazides 11 drugs
• C03C High-ceiling diuretics 45 drugs
• C03D Potassium-sparing agents 53 drugs
• C03E Diuretics and potassium-sparing agents in combination 6 drugs
• C03X Other diuretics 21 drugs