Eplerenone
Eplerenone. Selective mineralocorticoid receptor antagonist — fewer anti-androgenic / progestational side effects than spironolactone (no… Oral half-life 3 h.
Selective mineralocorticoid receptor antagonist — fewer anti-androgenic / progestational side effects than spironolactone (no gynecomastia). Approved for HFrEF post-MI + resistant hypertension. Hyperkalemia risk; CYP3A4 substrate (avoid with strong inhibitors).
PK: A GOOD PAPER MINED FOR LESS THAN HALF OF WHAT WAS HUNG ON IT - class 1 in its most deceptive form, since the citation is genuine, human and on-topic. t-half 3.0 is verbatim, "plasma concentrations of EP declined with a half-life of 3.0 h". ka 1.7 is not: the only 1.7 in that abstract is a CONCENTRATION, "a mean EP Cmax of 1.72 mug/ml", and back-derivation is excluded because the stored pair implies a 1.36 h peak whereas reproducing the quoted 1.2 h would need about 2.0 - so the Cmax collision is the only route left, and it is removed. V 43 L is the LOWER ENDPOINT of the label 43-to-90 L range, and class 6 applies in its diagnosable form because eplerenone has no human intravenous formulation in any abstract, making 43 necessarily V/F; F is pinned to 1 rather than left at an unsourced 0.69, for which a search returns ZERO records and whose nearest neighbour, 66.6%, is urinary mass balance. TWO FINDINGS WORTH KEEPING: the earlier decision to skip a free fraction here was RIGHT, on this paper own words - "Plasma protein binding was moderate (33-60%) but concentration-dependent over the therapeutic concentration range" - and class 8 is affirmatively EXCLUDED, "EP and its metabolites did not preferentially partition into the red blood cells", so a plasma-referenced volume is correct and this need not be re-litigated.
Pharmacokinetics
- Oral — t½ 3 h · F 100% · Vd 43 L
Sources: PMID:14570778, PMID:26073023