Eplerenona Pentafarma Mechanism of Action

Pharmacology: Pharmacokinetics: Special Populations and Conditions: Age, Gender, and Race: The pharmacokinetics of eplerenone at a dose of 100 mg once daily has been investigated in the elderly (≥65 years), in males and females, and in Blacks. The pharmacokinetics of eplerenone did not differ significantly between males and females. At steady state, elderly subjects had increases in C_max (22%) and AUC (45%) compared with younger subjects (18 to 45 years). At steady state, C_max was 19% lower and AUC was 26% lower in Blacks (see Use in the Elderly under Precautions and Dosage & Administration).
Renal Insufficiency: The pharmacokinetics of eplerenone was evaluated in patients with varying degrees of renal insufficiency and in patients undergoing hemodialysis. Compared with control subjects, steady-state AUC and C_max were increased by 38% and 24%, respectively, in patients with severe renal impairment and were decreased by 26% and 3%, respectively, in patients undergoing hemodialysis. No correlation was observed between plasma clearance of eplerenone and creatinine clearance. Eplerenone is not removed by hemodialysis (see Hyperkalemia under Precautions).
Hepatic Insufficiency: The pharmacokinetics of eplerenone 400 mg has been investigated in patients with moderate (Child-Pugh Class B) hepatic impairment and compared with normal subjects. Steady-state C_max and AUC of eplerenone were increased by 3.6% and 42%, respectively (see Dosage & Administration).
Heart Failure: The pharmacokinetics of eplerenone 50 mg was evaluated in 8 patients with heart failure (NYHA classification II-IV) and 8 matched (gender, age, weight) healthy controls. Compared with the controls, steady state AUC and C_max in patients with stable heart failure were 38% and 30% higher, respectively.
Drug-Drug Interactions (see Interactions): Drug-drug interaction studies were conducted with a 100 mg dose of eplerenone.
Eplerenone is metabolized primarily by CYP3A4. A potent inhibitor of CYP3A4 (ketoconazole) caused increased exposure of 5.4 fold; while less potent CYP3A4 inhibitors (erythromycin, saquinavir, verapamil, and fluconazole) resulted in increases ranging from 2.0-2.9 fold.
Grapefruit juice caused only a small increase (about 25%) in exposure (see Interactions).
Eplerenone is not an inhibitor of CYP1A2, CYP3A4, CYP2C19, CYP2C9, or CYP2D6. Eplerenone did not inhibit the metabolism of amiodarone, amlodipine, astemizole, chlorzoxazone, cisapride, dexamethasone, dextromethorphan, diclofenac, 17α-ethinyl estradiol, fluoxetine, losartan, lovastatin, mephobarbital, methylphenidate, methylprednisolone, metoprolol, midazolam, nifedipine, phenacetin, phenytoin, simvastatin, tolbutamide, triazolam, verapamil, and warfarin in vitro. Eplerenone is not a substrate or an inhibitor of P-Glycoprotein at clinically relevant doses.
No clinically significant drug-drug pharmacokinetic interactions were observed when eplerenone was administered with cisapride, cyclosporine, digoxin, glyburide, midazolam, oral contraceptives (norethindrone/ethinyl estradiol), simvastatin, or warfarin. St. John's Wort (a CYP3A4 inducer) caused a small (about 30%) decrease in eplerenone AUC.
No significant changes in eplerenone pharmacokinetics were observed when eplerenone was administered with aluminum and magnesium-containing antacids.