atc code c03 atc code c03 atc code c03 diuretics is a therapeutic subgroup of the anatomical therapeutic chemical classification system, a system of alphanumeric codes developed by the world health organization (who) for the classification of drugs and other medical products. subgroup c03 is part of the anatomical group c cardiovascular system. atc codes c cardiovascular system c01 cardiac therapy c02 antihypertensives c03 diuretics c04 peripheral vasodilators c05 vasoprotectives c07 beta blocking agents c08 calcium channel blockers c09 agents acting on the renin–angiotensin system c10 lipid modifying agents a b c d g h qi j l m n p r s v codes for veterinary use (atcvet codes) can be created by placing the letter q in front of the human atc code: for example, qc03. atcvet codes without corresponding human atc codes are cited with the leading q in the following list.national issues of the atc classification may include additional codes not present in this list, which follows the who version. c03a low-ceiling diuretics, thiazides c03aa thiazides, plain c03aa01 bendroflumethiazide c03aa02 hydroflumethiazide c03aa03 hydrochlorothiazide c03aa04 chlorothiazide c03aa05 polythiazide c03aa06 trichlormethiazide c03aa07 cyclopenthiazide c03aa08 methyclothiazide c03aa09 cyclothiazide c03aa13 mebutizide qc03aa56 trichlormethiazide, combinations c03ab thiazides and potassium in combination c03ab01 bendroflumethiazide and potassium c03ab02 hydroflumethiazide and potassium c03ab03 hydrochlorothiazide and potassium c03ab04 chlorothiazide and potassium c03ab05 polythiazide and potassium c03ab06 trichlormethiazide and potassium c03ab07 cyclopenthiazide and potassium c03ab08 methyclothiazide and potassium c03ab09 cyclothiazide and potassium c03ah thiazides, combinations with psycholeptics and/or analgesics c03ah01 chlorothiazide, combinations c03ah02 hydroflumethiazide, combinations c03ax thiazides, combinations with other drugs c03ax01 hydrochlorothiazide, combinations c03b low-ceiling diuretics, excluding thiazides c03ba sulfonamides, plain c03ba02 quinethazone c03ba03 clopamide c03ba04 chlortalidone c03ba05 mefruside c03ba07 clofenamide c03ba08 metolazone c03ba09 meticrane c03ba10 xipamide c03ba11 indapamide c03ba12 clorexolone c03ba13 fenquizone c03ba82 clorexolone, combinations with psycholeptics c03bb sulfonamides and potassium in combination c03bb02 quinethazone and potassium c03bb03 clopamide and potassium c03bb04 chlortalidone and potassium c03bb05 mefruside and potassium c03bb07 clofenamide and potassium c03bc mercurial diuretics c03bc01 mersalyl c03bd xanthine derivatives c03bd01 theobromine c03bx other low-ceiling diuretics c03bx03 cicletanine c03c high-ceiling diuretics c03ca sulfonamides, plain c03ca01 furosemide c03ca02 bumetanide c03ca03 piretanide c03ca04 torasemide c03cb sulfonamides and potassium in combination c03cb01 furosemide and potassium c03cb02 bumetanide and potassium c03cc aryloxyacetic acid derivatives c03cc01 etacrynic acid c03cc02 tienilic acid c03cd pyrazolone derivatives c03cd01 muzolimine c03cx other high-ceiling diuretics c03cx01 etozolin c03d aldosterone antagonists and other potassium-sparing agents c03da aldosterone antagonists c03da01 spironolactone c03da02 potassium canrenoate c03da03 canrenone c03da04 eplerenone c03da05 finerenone c03db other potassium-sparing agents c03db01 amiloride c03db02 triamterene c03e diuretics and potassium-sparing agents in combination c03ea low-ceiling diuretics and potassium-sparing agents c03ea01 hydrochlorothiazide and potassium-sparing agents c03ea02 trichlormethiazide and potassium-sparing agents c03ea03 epitizide and potassium-sparing agents c03ea04 altizide and potassium-sparing agents c03ea05 mebutizide and potassium-sparing agents c03ea06 chlortalidone and potassium-sparing agents c03ea07 cyclopenthiazide and potassium-sparing agents c03ea12 metolazone and potassium-sparing agents c03ea13 bendroflumethiazide and potassium-sparing agents c03ea14 butizide and potassium-sparing agents c03eb high-ceiling diuretics and potassium-sparing agents c03eb01 furosemide and potassium-sparing agents c03eb02 bumetanide and potassium-sparing agents c03x other diuretics c03xa vasopressin antagonists c03xa01 tolvaptan c03xa02 conivaptan