No abstract

Mirabegron pharmacokinetics were linear after i.v. dosing (7.5 - 50 mg), but increased more than proportionally after oral dosing (25 - 150 mg) as a result of increased F. Sex differences in exposure could be explained by body weight and for oral dosing, also by F. Mirabegron was in general well tolerated up to the highest doses studied, 50 mg i.v. and 150 mg oral.

To explore the role of β -adrenoceptors (ARs) in the heart rate response to the selective β -adrenoceptor agonist mirabegron, 12 young male volunteers received single oral doses of the nonselective β -AR antagonist propranolol (160 mg), the selective β -AR antagonist bisoprolol (10 mg), or placebo on days 1 and 5 of each period in a 3-period crossover study. On day 5, dosing was followed by a supratherapeutic dose of mirabegron (200 mg). Vital signs, impedance cardiography, and plasma renin activity were collected. Mirabegron increased heart rate and systolic blood pressure and reduced stroke volume, whereas cardiac output and diastolic blood pressure were unaffected. Mirabegron-induced changes were attenuated by propranolol and bisoprolol. The data indicate that mirabegron has a positive chronotropic effect at supratherapeutic concentrations, which is at least partly mediated by stimulation of β -AR.

Mirabegron AUC(∞) and C(max) increased 118 and 92 %, respectively, in subjects with severe renal impairment, and 65 and 175 %, respectively, in subjects with moderate hepatic impairment. Pharmacokinetic changes observed in subjects with mild or moderate renal impairment or mild hepatic impairment are of small magnitude and likely to be without clinical importance.

Background and Objectives Roxadustat is an orally active hypoxia-inducible factor prolyl hydroxylase inhibitor for anemia in chronic kidney disease. The pharmacokinetics, metabolic profile, and pharmacodynamics of roxadustat were investigated in subjects with different degrees of kidney function. Methods This phase 1 open-label study enrolled subjects with normal and severely impaired kidney function, and end-stage renal disease (ESRD) on continuous ambulatory peritoneal dialysis (CAPD) or automated peritoneal dialysis (APD) or hemodialysis/hemodiafiltration (HD/HDF). All subjects received a single 100-mg dose of oral roxadustat. Within a single-sequence, two-treatment period design (P1/P2), subjects with ESRD on HD/HDF received roxadustat 2 h after (P1) and 2 h before (P2) a dialysis session. Area under the plasma concentration–time curve (AUC) from administration to infinity (AUC inf ), maximum concentration ( C max ), and terminal elimination half-life ( t 1/2 ) were assessed for roxadustat; AUC and C max were assessed for erythropoietin. Results Thirty-four subjects were enrolled and received roxadustat (normal kidney function, n = 12; severely impaired kidney function, n = 9; ESRD on CAPD/APD, n = 1; ESRD on HD/HDF, n = 12). The geometric least-square mean ratio of AUC inf was 223% and 195% in subjects with severely impaired kidney function and ESRD on HD/HDF, respectively, relative to subjects with normal kidney function; C max and t 1/2 were comparable. The pharmacokinetic profile of roxadustat was not affected by HD/HDF. AUC inf and t 1/2 for the metabolites of roxadustat increased in subjects with kidney impairment. The AUC and C max of erythropoietin increased in subjects with severely impaired kidney function or ESRD on HD/HDF. Roxadustat was well tolerated. Conclusions Kidney function impairment increased the AUC of roxadustat and its metabolites. The C max and t 1/2 of roxadustat were comparable among groups. Roxadustat and its metabolites were not cleared by HD/HDF. Clinical Trials Registration Number: NCT02965040. Electronic supplementary material The online version of this article (10.1007/s13318-020-00658-w) contains supplementary material, which is available to authorized users.