AimsTo evaluate apixaban single dose safety, tolerability, pharmacokinetics and pharmacodynamics and assess the effect of food on apixaban pharmacokinetics.MethodsA double-blind, placebo-controlled, single ascending-dose, first-in-human study assessed apixaban safety, pharmacokinetics and pharmacodynamics in healthy subjects randomized to oral apixaban (n = 43; 0.5–2.5 mg as solution or 5–50 mg as tablets) or placebo (n = 14) under fasted conditions. An open label, randomized, two treatment crossover study investigated apixaban pharmacokinetics/pharmacodynamics in healthy subjects (n = 21) administered apixaban 10 mg in fasted and fed states. Both studies measured apixaban plasma concentration, international normalized ratio (INR), activated partial thromboplastin time (aPTT) and prothrombin time (PT) or a modified PT (mPT).ResultsIn the single ascending-dose study increases in apixaban exposure appeared dose-proportional. Median tmax occurred 1.5–3.3 h following oral administration. Mean terminal half-life ranged between 3.6 and 6.8 h following administration of solution doses ≤2.5 mg and between 11.1 and 26.8 h for tablet doses ≥5 mg. Concentration-related changes in pharmacodynamic assessments were observed. After a 50 mg dose, peak aPTT, INR and mPT increased by 1.2-, 1.6- and 2.9-fold, respectively, from baseline. In the food effect study: 90% confidence intervals of geometric mean ratios of apixaban Cmax and AUC in a fed vs. fasted state were within the predefined no effect (80–125%) range. Apixaban half-life was approximately 11.5 h. The effect of apixaban on INR, PT and aPTT was comparable following fed and fasted administration.ConclusionsSingle doses of apixaban were well tolerated with a predictable pharmacokinetic/pharmacodynamic profile and a half-life of approximately 12 h. Apixaban can be administered with or without food.

Multiple oral doses of apixaban were safe and well tolerated over a 10-fold dose range, with pharmacokinetics with low variability and concentration-related increases in clotting time measures.

OBJECTIVETo examine the effect of dapagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, on the major components of renal glucose reabsorption (decreased maximum renal glucose reabsorptive capacity [TmG], increased splay, and reduced threshold), using the pancreatic/stepped hyperglycemic clamp (SHC) technique.RESEARCH DESIGN AND METHODSSubjects with type 2 diabetes (n = 12) and matched healthy subjects (n = 12) underwent pancreatic/SHC (plasma glucose range 5.5–30.5 mmol/L) at baseline and after 7 days of dapagliflozin treatment. A pharmacodynamic model was developed to describe the major components of renal glucose reabsorption for both groups and then used to estimate these parameters from individual glucose titration curves.RESULTSAt baseline, type 2 diabetic subjects had elevated TmG, splay, and threshold compared with controls. Dapagliflozin treatment reduced the TmG and splay in both groups. However, the most significant effect of dapagliflozin was a reduction of the renal threshold for glucose excretion in type 2 diabetic and control subjects.CONCLUSIONSThe SGLT2 inhibitor dapagliflozin improves glycemic control in diabetic patients by reducing the TmG and threshold at which glucose is excreted in the urine.

Four randomized, placebo-controlled, crossover studies were conducted among 282 healthy subjects to investigate whether an interaction exists between clopidogrel (300-mg loading dose/75-mg/day maintenance dose) and the proton-pump inhibitor (PPI) omeprazole (80 mg) when they are administered simultaneously (study 1); whether the interaction, if any, can be mitigated by administering clopidogrel and omeprazole 12 h apart (study 2) or by increasing clopidogrel to 600-mg loading/150-mg/day maintenance dosing (study 3); and whether the interaction applies equally to the PPI pantoprazole (80 mg) (study 4). Relative to levels after administration of clopidogrel alone in studies 1,2,3, and 4, coadministration of PPI decreased the AUC(0-24) of the clopidogrel active metabolite H4 by 40, 47, 41, and 14% (P ≤ 0.002), respectively; increased maximal platelet aggregation (MPA) induced by 5 micromol/l adenosine diphosphate (ADP) by 8.0, 5.6, 8.1, and 4.3% (P ≤ 0.014), respectively; and increased the vasodilator-stimulated phosphoprotein phosphorylation-platelet reactivity index (VASP-PRI) by 20.7, 27.1, 19.0 (P < 0.0001), and 3.9% (P = 0.3319), respectively. The results suggest that a metabolic drug-drug interaction exists between clopidogrel and omeprazole but not between clopidogrel and pantoprazole.

AIMApixaban is an oral, direct, factor-Xa inhibitor approved for thromboprophylaxis in patients who have undergone elective hip or knee replacement surgery and for prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation. This open label, parallel group study investigated effects of extremes of body weight on apixaban pharmacokinetics, pharmacodynamics, safety and tolerability. METHODFifty-four healthy subjects were enrolled [18 each into low (Յ50 kg), reference (65-85 kg) and high (Ն120 kg) body weight groups]. Following administration of a single oral dose of 10 mg apixaban, plasma and urine samples were collected for determination of apixaban pharmacokinetics and anti-factor Xa activity. Adverse events, vital signs and laboratory assessments were monitored. RESULTSCompared with the reference body weight group, low body weight had approximately 27% [90% confidence interval (CI): 8-51%] and 20% (90% CI: 11-42%) higher apixaban maximum observed plasma concentration (Cmax) and area under the concentration-time curve extrapolated to infinity (AUC(0,•)), respectively, and high body weight had approximately 31% (90% CI: 18-41%) and 23% (90% CI: 9-35%) lower apixaban Cmax and AUC(0,•), respectively. Apixaban renal clearance was similar across the weight groups. Plasma anti-factor Xa activity showed a direct, linear relationship with apixaban plasma concentration, regardless of body weight group. Apixaban was well tolerated in this study. CONCLUSIONThe modest change in apixaban exposure is unlikely to require dose adjustment for apixaban based on body weight alone. However, caution is warranted in the presence of additional factors (such as severe renal impairment) that could increase apixaban exposure.

Sodium-glucose co-transporter 2 (SGLT2) is predominantly expressed in the S1 segment of the proximal tubule of the kidney and is the major transporter responsible for mediating renal glucose reabsorption. Dapagliflozin is an orally active, highly selective SGLT2 inhibitor that improves glycemic control in patients with type 2 diabetes mellitus (T2DM) by reducing renal glucose reabsorption leading to urinary glucose excretion (glucuresis). Orally administered dapagliflozin is rapidly absorbed generally achieving peak plasma concentrations within 2 h. Dose-proportional systemic exposure to dapagliflozin has been observed over a wide dose range (0.1-500 mg) with an oral bioavailability of 78 %. Dapagliflozin has extensive extravascular distribution (mean volume of distribution of 118 L). Dapagliflozin metabolism occurs predominantly in the liver and kidneys by uridine diphosphate-glucuronosyltransferase-1A9 to the major metabolite dapagliflozin 3-O-glucuronide (this metabolite is not an SGLT2 inhibitor at clinically relevant exposures). Dapagliflozin is not appreciably cleared by renal excretion (<2 % of dose is recovered in urine as parent). Dapagliflozin 3-O-glucuronide elimination occurs mainly via renal excretion, with 61 % of a dapagliflozin dose being recovered as this metabolite in urine. The half-life for orally administered dapagliflozin 10 mg was 12.9 h. Maximal increases in urinary glucose excretion were seen at doses ≥20 mg/day in patients with T2DM. No clinically relevant differences were observed in dapagliflozin exposure with respect to age, race, sex, body weight, food, or presence of T2DM. Pharmacodynamic changes are dependent on plasma glucose and renal function, and decreases in urinary glucose excretion were observed due to the lower filtered load (plasma glucose × glomerular filtration rate) in healthy volunteers compared to subjects with T2DM. After multiple doses of dapagliflozin, urinary glucose excretion was associated with dose-related decreases in plasma glucose parameters in subjects with T2DM. Patients with severe renal or hepatic impairment show higher systemic exposure to dapagliflozin. No clinically relevant drug interactions were observed that would necessitate dose adjustment of dapagliflozin when administered with other antidiabetic or cardiovascular medications, as well as drugs that could potentially influence dapagliflozin metabolism.

Aim Apixaban is an orally active inhibitor of coagulation factor Xa and is eliminated by multiple pathways, including renal and non‐renal elimination. Non‐renal elimination pathways consist of metabolism by cytochrome P450 (CYP) enzymes, primarily CYP3A4, as well as direct intestinal excretion. Two single sequence studies evaluated the effect of ketoconazole (a strong dual inhibitor of CYP3A4 and P‐glycoprotein [P‐gp]) and diltiazem (a moderate CYP3A4 inhibitor and a P‐gp inhibitor) on apixaban pharmacokinetics in healthy subjects. Method In the ketoconazole study, 18 subjects received apixaban 10 mg on days 1 and 7, and ketoconazole 400 mg once daily on days 4–9. In the diltiazem study, 18 subjects received apixaban 10 mg on days 1 and 11 and diltiazem 360 mg once daily on days 4–13. Results Apixaban maximum plasma concentration and area under the plasma concentration–time curve extrapolated to infinity increased by 62% (90% confidence interval [CI], 47, 78%) and 99% (90% CI, 81, 118%), respectively, with co‐administration of ketoconazole, and by 31% (90% CI, 16, 49%) and 40% (90% CI, 23, 59%), respectively, with diltiazem. Conclusion A 2‐fold and 1.4‐fold increase in apixaban exposure was observed with co‐administration of ketoconazole and diltiazem, respectively.

This open-label study evaluated apixaban pharmacokinetics, pharmacodynamics, and safety in subjects with mild, moderate, or severe renal impairment and in healthy subjects following a single 10-mg oral dose. The primary analysis determined the relationship between apixaban AUC∞ and 24-hour creatinine clearance (CLcr ) as a measure of renal function. The relationships between 24-hour CLcr and iohexol clearance, estimated CLcr (Cockcroft-Gault equation), and estimated glomerular filtration rate (modification of diet in renal disease [MDRD] equation) were also assessed. Secondary objectives included assessment of safety and tolerability as well as international normalized ratio (INR) and anti-factor Xa activity as pharmacodynamic endpoints. The regression analysis showed that decreasing renal function resulted in modestly increased apixaban exposure (AUC∞ increased by 44% in severe impairment with a 24-hour CLcr of 15 mL/min, compared with subjects with normal renal function), but it did not affect Cmax or the direct relationship between apixaban plasma concentration and anti-factor Xa activity or INR. The assessment of renal function measured by iohexol clearance, Cockcroft-Gault, and MDRD was consistent with that determined by 24-hour CLcr . Apixaban was well tolerated in this study. These results suggest that dose adjustment of apixaban is not required on the basis of renal function alone.