title: Spironolactone and canrenoate-K: relative potency at steady state.
abstract: Relative dose ratios of the mineralocorticoid antagonists spironolactone (100 mg and 200 mg daily) and canrenoate-K (200 mg daily) at steady state were defined in six healthy subjects with fludrecortisone as the mineralocorticoid agonist. The urine log 10 Na/K responses during spironolactone treatments were consistent with the law of mass action. The potency of canrenoate-K was 0.68 (95% C.L. 0.53 to 0.89) that of spironolactone on a weight basis. Approximately 72% of the renal antimineralocorticoid activity of spironolactone could attributed to the metabolite canrenone. The results at steady state are contrasted with those of a previously study comparing single doses of spironolactone and canrenoate-K.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D002191:Canrenoic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D002192:Canrenone / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005438:Fludrocortisone / Q000037:antagonists & inhibitors; D006801:Humans; D008297:Male; D011188:Potassium / Q000652:urine; D011245:Pregnadienes / Q000494:pharmacology*; D012964:Sodium / Q000652:urine; D012996:Solutions; D013148:Spironolactone / Q000008:administration & dosage / Q000494:pharmacology*; D013607:Tablets; D013810:Therapeutic Equivalency; D013997:Time Factors
chemical_list: D011245:Pregnadienes; D012996:Solutions; D013607:Tablets; D013148:Spironolactone; D002192:Canrenone; D002191:Canrenoic Acid; D012964:Sodium; D011188:Potassium; D005438:Fludrocortisone