“…However, no interaction of aliskiren with cytochrome P450 (P450) isoenzymes was found in human liver microsomes in vitro , suggesting a low potential for clinically significant drug interactions of aliskiren. Indeed, no clinically relevant pharmacokinetic interactions have been observed between aliskiren and the P450 substrates celecoxib, digoxin, lovastatin, or warfarin, or the P450 inhibitor cimetidine, in healthy volunteers (Dieterle et al, 2004(Dieterle et al, , 2005Dieterich et al, 2006). Animal studies indicate that aliskiren is a substrate for the efflux transporter Pglycoprotein, which may play a role in the hepatobiliary/intestinal excretion of the drug; however, the lack of pharmacokinetic interaction between aliskiren and the P-glycoprotein substrate digoxin indicates that aliskiren does not inhibit P-glycoprotein activity (Dieterich et al, 2006).…”