Lisdexamfetamine prodrug activation by peptidase-mediated hydrolysis in the cytosol of red blood cells

Abstract

Lisdexamfetamine dimesylate (LDX) is approved as a once-daily treatment for attention-deficit/hyperactivity disorder in children, adolescents, and adults in some countries. LDX is a prodrug comprising d-amphetamine covalently linked to l-lysine via a peptide bond. Following oral administration, LDX is rapidly taken up from the small intestine by active carrier-mediated transport, probably via peptide transporter 1. Enzymatic hydrolysis of the peptide bond to release d-amphetamine has previously been shown to occur in human red blood cells but not in several other tissues. Here, we report that LDX hydrolytic activity resides in human red blood cell lysate and cytosolic extract but not in the membrane fraction. Among several inhibitors tested, a protease inhibitor cocktail, bestatin, and ethylenediaminetetra-acetic acid each potently inhibited d-amphetamine production from LDX in cytosolic extract. These results suggest that an aminopeptidase is responsible for hydrolytic cleavage of the LDX peptide bond, although purified recombinant aminopeptidase B was not able to release d-amphetamine from LDX in vitro. The demonstration that aminopeptidase-like activity in red blood cell cytosol is responsible for the hydrolysis of LDX extends our understanding of the smooth and consistent systemic delivery of d-amphetamine by LDX and the long daily duration of efficacy of the drug in relieving the symptoms of attention-deficit/hyperactivity disorder.

Acute effects of lisdexamfetamine and D-amphetamine on social cognition and cognitive performance in a placebo-controlled study in healthy subjects

“…Lisdexamfetamine is a newer inactive prodrug formulation of D-amphetamine (Hutson et al 2014). Inactive lisdexamfetamine is relatively slowly converted to its active metabolite D-amphetamine in the circulation by enzymatic hydrolysis within red blood cells (Pennick 2010;Sharman and Pennick 2014), thus reducing the subjective effects and risk of parenteral misuse of lisdexamfetamine compared with D-amphetamine. However, when used orally at a high dose, the pharmacokinetics and subjective effects of lisdexamfetamine are Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00213-018-4849-0) contains supplementary material, which is available to authorized users.…”

Pharmacokinetics and Pharmacodynamics of Lisdexamfetamine Compared with D-Amphetamine in Healthy Subjects

“…Lisdexamfetamine is thought to have lower abuse potential than D -amphetamine ( Heal et al, 2013 ). Inactive lisdexamfetamine is completely (>98%) converted to its active metabolite D -amphetamine in the circulation ( Pennick, 2010 ; Sharman and Pennick, 2014 ). When lisdexamfetamine is misused intranasally or intravenously, the pharmacokinetics are similar to oral use ( Jasinski and Krishnan, 2009b ; Ermer et al, 2011 ), and the subjective effects are not enhanced by parenteral administration in contrast to D -amphetamine ( Lile et al, 2011 ) thus reducing the risk of parenteral misuse of lisdexamfetamine compared with D -amphetamine.…”

Lisdexamfetamine Dimesylate: Prodrug Delivery, Amphetamine Exposure and Duration of Efficacy

“…Once in the blood, LDX is hydrolysed in erythrocyte cytosol by an unknown aminopeptidase, yielding pharmacologically active d- amphetamine (Fig. 2 ) [ 11 , 12 ]. The d- amphetamine generated from LDX crosses the blood-brain barrier to access binding sites in the central nervous system [ 13 ] and to exert therapeutic effects by increasing noradrenergic and dopaminergic neurotransmission.…”