digoxin and aliskiren

An estimated 5.1 million Americans have chronic heart failure and this is expected to increase 25% by 2030. Heart failure is a clinical syndrome that evolves from either functional or structural changes to the ventricles that lead to filling or ejection abnormalities. Thus far, pharmacotherapy has been show to be beneficial in patients only with reduced ejection fraction; however, new therapies have been developed in hopes of reducing the burden of heart failure. In this review, we will discuss current pharmacotherapies recommended in American College of Cardiology/American Heart Association guidelines, the evidence behind these recommendations as well as new and emerging therapies that have been developed.

Topics: Adrenergic beta-Antagonists; American Heart Association; Amides; Aminobutyrates; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Anticoagulants; Antihypertensive Agents; Atrial Natriuretic Factor; Benzazepines; Biphenyl Compounds; Calcium Channel Blockers; Cardiology; Cardiotonic Agents; Cardiovascular Agents; Digoxin; Diuretics; Drug Combinations; Erythropoietin; Evidence-Based Medicine; Fumarates; Heart Failure; Hematinics; Humans; Hydralazine; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Iron; Isosorbide Dinitrate; Ivabradine; Mineralocorticoid Receptor Antagonists; Peptide Fragments; Platelet Aggregation Inhibitors; Practice Guidelines as Topic; Societies, Medical; Stroke Volume; Tetrazoles; United States; Valsartan; Vasodilator Agents

Heart failure (HF) can rightfully be called the epidemic of the 21(st) century. Historically, the only available medical treatment options for HF have been diuretics and digoxin, but the capacity of these agents to alter outcomes has been brought into question by the scrutiny of modern clinical trials. In the past 4 decades, neurohormonal blockers have been introduced into clinical practice, leading to marked reductions in morbidity and mortality in chronic HF with reduced left ventricular ejection fraction (LVEF). Despite these major advances in pharmacotherapy, our understanding of the underlying disease mechanisms of HF from epidemiological, clinical, pathophysiological, molecular, and genetic standpoints remains incomplete. This knowledge gap is particularly evident with respect to acute decompensated HF and HF with normal (preserved) LVEF. For these clinical phenotypes, no drug has been shown to reduce long-term clinical event rates substantially. Ongoing developments in the pharmacotherapy of HF are likely to challenge our current best-practice algorithms. Novel agents for HF therapy include dual-acting neurohormonal modulators, contractility-enhancing agents, vasoactive and anti-inflammatory peptides, and myocardial protectants. These novel compounds have the potential to enhance our armamentarium of HF therapeutics.

Topics: Amides; Aminobutyrates; Atrial Natriuretic Factor; Biphenyl Compounds; Digoxin; Drug Combinations; Fumarates; Heart Failure; Humans; Natriuretic Peptides; Peptide Fragments; Snake Venoms; Tetrazoles; Valsartan

This study investigated the potential pharmacokinetic interaction between the direct renin inhibitor aliskiren and modulators of P-glycoprotein and cytochrome P450 3A4 (CYP3A4). Aliskiren stimulated in vitro P-glycoprotein ATPase activity in recombinant baculovirus-infected Sf9 cells with high affinity (K(m) 2.1 micromol/L) and was transported by organic anion-transporting peptide OATP2B1-expressing HEK293 cells with moderate affinity (K(m) 72 micromol/L). Three open-label, multiple-dose studies in healthy subjects investigated the pharmacokinetic interactions between aliskiren 300 mg and digoxin 0.25 mg (n = 22), atorvastatin 80 mg (n = 21), or ketoconazole 200 mg bid (n = 21). Coadministration with aliskiren resulted in changes of <30% in AUC(tau) and C(max,ss) of digoxin, atorvastatin, o-hydroxy-atorvastatin, and rho-hydroxy-atorvastatin, indicating no clinically significant interaction with P-glycoprotein or CYP3A4 substrates. Aliskiren AUC(tau) was significantly increased by coadministration with atorvastatin (by 47%, P < .001) or ketoconazole (by 76%, P < .001) through mechanisms most likely involving transporters such as P-glycoprotein and organic anion-transporting peptide and possibly through metabolic pathways such as CYP3A4 in the gut wall. These results indicate that aliskiren is a substrate for but not an inhibitor of P-glycoprotein. On the basis of the small changes in exposure to digoxin and atorvastatin and the <2-fold increase in exposure to aliskiren during coadministration with atorvastatin and ketoconazole, the authors conclude that the potential for clinically relevant drug interactions between aliskiren and these substrates and/or inhibitors of P-glycoprotein/CPY3A4/OATP is low.

Topics: Adult; Amides; Animals; Antifungal Agents; Atorvastatin; ATP Binding Cassette Transporter, Subfamily B, Member 1; Caco-2 Cells; Cell Line; Cytochrome P-450 CYP3A; Digoxin; Drug Interactions; Female; Fumarates; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Ketoconazole; Male; Organic Anion Transporters; Pyrroles; Renin; Tissue Distribution; Young Adult