Adult: Initially, 25 mg once daily, titrate to 50 mg once daily w/in 4 wk if tolerated. Dose adjustment based on serum K level: <5 mEq/L: Increase 25 mg every other day to 25 mg daily or 25 mg daily to 50 mg daily. 5-5.4 mEq/L: No dosage adjustment. 5.5-5.9 mEq/L: Decrease from 50 mg daily to 25 mg daily, or 25 mg daily to 25 mg every other day, or 25 mg every other day to withhold therapy. ≥6 mEq/L: Withhold therapy; restart at 25 mg every other day when K level falls to <5.5 mEq/L.
Oral Hypertension
Adult: As monotherapy or in combination w/ other antihypertensives. Initially, 50 mg daily. Max: 50 mg bid.
Special Patient Group
Patient on mild to moderate CYP3A4 inhibitors: Max: 25 mg once daily.
CrCl <30 mL/min. Concomitant use w/ potent CYP3A4 inhibitors. Patient treated for HTN: Type 2 DM w/ microalbuminuria. CrCl ≤50 mL/min. Concomitant use w/ K-sparing diuretics or K supplements.
Special Precautions
Diabetic patient w/ CHF post-MI. Renal and severe hepatic impairment. Pregnancy and lactation.
Adverse Reactions
Hyperkalaemia, urinary tract disorders, CNS and GI disturbances, dizziness, fatigue, flu-like symptoms, cough, diarrhoea, abdominal pain, decreased serum Na concentrations, increased serum creatinine concentrations, abnormal vag bleeding, gynaecomastia, hypercholesterolemia, hypertriglyceridemia, mastodynia, or albuminuria.
Monitor BP, serum K levels (prior to treatment, w/in the 1st wk and periodically thereafter).
Overdosage
Symptoms: Hyperkalaemia, hypotension. Management: Symptomatic and supportive treatment. Admin activated charcoal. Initiate standard therapy for hyperkalaemia.
Drug Interactions
May increase risk of hyperkalaemia w/ ACE inhibitors and/or angiotension receptor blocker, ciclosporin, tacrolimus, trimethoprim. May reduce antihypertensive effect w/ NSAIDs, glucocorticoids, tetracosactide. May enhance hypotensive effect of α1-blockers (e.g. alfuzosin, prazosin), TCAs, amifostine, baclofen, neuroleptics. May increase plasma level w/ mild to moderate CYP3A4 inhibitors (e.g. fluconazole, erythromycin, saquinavir, amiodarone, diltiazem, verapamil). Potentially Fatal: Significantly increased plasma level w/ potent CYP3A4 inhibitors (e.g. itraconazole, nefazodone, clarithromycin, telithromycin, ketoconazole, nelfinavir, ritonavir). May enhance hyperkalaemic effect of K-sparing diuretics or K supplements in patients w/ HTN.
Food Interaction
May reduce serum level w/ St John's wort. May increase serum level w/ grapefruit juice.
Action
Description: Eplerenone selectively binds to the mineralocorticoid receptor and blocks the binding of aldosterone, a key component in the renin-angiotensin-aldosterone-system, which is involved in the regulation of BP and pathophysiology of CV disease. Aldosterone binds to mineralocorticoid receptors in both epithelial (e.g. kidney, GI tract) and nonepithelial (e.g. heart, blood vessels, brain) tissues; causing increases in BP by inducing Na reabsorption, vascular remodelling, water retention, endothelial dysfunction and possibly other mechanisms. Pharmacokinetics: Absorption: Bioavailability: 69%. Time to peak plasma concentration: Approx 1.5 hr. Distribution: Volume of distribution: 43-90 L. Plasma protein binding: Approx 50% (primarily to α1-acid glycoprotein). Metabolism: Primarily hepatic by CYP3A4 isoenzyme to inactive metabolites. Excretion: Via urine (approx 67%); faeces (32%); <5% as unchanged drug in the urine and faeces. Elimination half-life: Approx 4-6 hr.
Anon. Eplerenone. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 11/11/2014.Buckingham R (ed). Eplerenone. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 11/11/2014.Eplerenone tablet (Apotex Corp). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 11/11/2014.Inspra Tablets. U.S. FDA. https://www.fda.gov/. Accessed 11/11/2014.Joint Formulary Committee. Eplerenone. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 11/11/2014.McEvoy GK, Snow EK, Miller J et al (eds). Eplerenone. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 11/11/2014.