Comparison of Capillary and Venous Drug Concentrations After Administration of a Single Dose of Risperidone, Paliperidone, Quetiapine, Olanzapine, or Aripiprazole.

Risperidone, paliperidone, quetiapine, olanzapine, and aripiprazole are antipsychotic drugs approved for treating various psychiatric disorders, including schizophrenia. The objective of this randomized, parallel-group, open-label study was to compare finger-stick-based capillary with corresponding venous whole-blood and plasma concentrations for these drugs after administration of a single dose to healthy volunteers. All whole-blood and plasma drug concentrations were measured with validated liquid chromatography-tandem mass spectrometry methods. Capillary and venous concentrations (both in plasma and whole blood) were in close agreement, although a time-dependent difference was observed, most obviously for olanzapine and paliperidone, with slightly higher capillary versus venous drug concentrations during the first hours after administering a single dose. The observed difference between capillary and venous plasma drug concentrations is expected not to be relevant in clinical practice, considering the wide window of therapeutic concentrations and the wide range of drug concentrations in the patient population for a given dose. Based on these results, finger-stick-based capillary drug concentrations have been shown to approximate venous drug concentrations.

Pharmacokinetics, Pharmacodynamics, and Safety of Single-Dose Canagliflozin in Healthy Chinese Subjects.

PURPOSE: Canagliflozin, an orally active sodium-glucose cotransporter 2 inhibitor, is approved in many countries as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. The recommended dose of canagliflozin is 100 or 300 mg once daily. This Phase I study was conducted to evaluate the pharmacokinetics, pharmacodynamics, and safety profile of canagliflozin in healthy Chinese subjects. METHODS: In this double-blind, single-dose, 3-way crossover study, 15 healthy subjects were randomized (1:1:1) to receive single oral doses of canagliflozin 100 mg, canagliflozin 300 mg, or placebo. Pharmacokinetic, pharmacodynamic, and safety assessments were made at prespecified time points. FINDINGS: All participants are healthy Chinese adults. Mean AUC and Cmax of canagliflozin increased in a dose-dependent manner after single-dose administration (AUC0-∞, 10,521 ng · h/mL for 100 mg, 33,583 ng · h/mL for 300 mg; Cmax, 1178 ng/mL for 100 mg, 4113 ng/mL for 300 mg). The mean apparent t½ and the median Tmax of canagliflozin were independent of dose (t½, 16.0 hours for 100 mg, 16.2 hours for 300 mg; Tmax, ~1 hour). Mean CL/F and renal clearance of canagliflozin were comparable between the 2 doses. Mean plasma metabolite to parent molar ratios for Cmax and AUC0-∞ were similar with both doses. Canagliflozin decreased the 24-hour mean renal threshold for glucose, calculated by using measured creatinine clearance to estimate the glomerular filtration rate (67.9 and 60.7 mg/dL for canagliflozin 100 and 300 mg, respectively) and 24-hour increased urinary glucose excretion (33.8 and 42.9 g for canagliflozin 100 and 300 mg, respectively) in a dose-dependent manner; the 24-hour plasma glucose profile remained largely unchanged. No deaths, hypoglycemic events, or discontinuations due to adverse events were observed. IMPLICATIONS: Pharmacokinetics (AUC and Cmax) of canagliflozin increased in a dose-dependent manner after single oral doses of canagliflozin (100 and 300 mg) in these healthy Chinese subjects. Tmax and t½ of canagliflozin were independent of the dose. Canagliflozin decreased the 24-hour mean renal threshold for glucose and increased urinary glucose excretion in a dose-dependent manner; these results are consistent with those observed in other patient populations. Canagliflozin was generally safe and well tolerated in these healthy Chinese subjects. ClinicalTrials.gov identifier: NCT01707316.

Effect of canagliflozin, a sodium glucose co-transporter 2 inhibitor, on the pharmacokinetics of oral contraceptives, warfarin, and digoxin in healthy participants.

OBJECTIVE: Drug-drug interactions between canagliflozin, a sodium glucose co-transporter 2 inhibitor approved for the management of type-2 diabetes mellitus, and an oral contraceptive (OC), warfarin, and digoxin were evaluated in three phase 1 studies in healthy participants. METHODS: All studies were open-label; study 1 included a fixed-sequence design, and studies 2 and 3 used a crossover design. Regimens were: study 1: OC (levonorgestrel (150 µg) + ethinyl estradiol (30 µg))/day (day 1), canagliflozin 200 mg/day (days 4 - 8), and canagliflozin with OC (day 9); study 2: canagliflozin 300 mg/day (days 1 - 12) with warfarin 30 mg/day (day 6) in period 1, and only warfarin 30 mg/day (day 1) in period 2, or vice versa; study 3: digoxin alone (0.5 mg/day (day 1) + 0.25 mg/day (days 2 - 7)) in period 1, and with canagliflozin 300 mg/day (days 1 - 7) in period 2, or vice versa. Pharmacokinetics (PK) were assessed at prespecified intervals; OC: days 1 and 9, canagliflozin: days 8 - 9 (study 1); warfarin: days 6 (period 1) and 1 (period 2) (study 2); and digoxin: days 5 - 7 (periods 1 and 2) (study 3). Warfarin's pharmacodynamics (PD; International Normalized Ratio (INR)) was assessed on days 6 (period 1) and 1 (period 2). RESULTS: Canagliflozin increased the plasma exposure of OC (maximum plasma concentration (Cmax): 22%, area under the curve (AUC): 6%) and digoxin (Cmax: 36%, AUC: 20%); but did not alter warfarin'€™s PK and PD. No clinically relevant safety findings (including hypoglycemia) were noted. CONCLUSION: Canagliflozin can be coadministered with OC, warfarin, or digoxin without dose adjustments. All treatments were well-tolerated.

Effects of rifampin, cyclosporine A, and probenecid on the pharmacokinetic profile of canagliflozin, a sodium glucose co-transporter 2 inhibitor, in healthy participants.

OBJECTIVE: Canagliflozin, a sodium-glucose co-transporter 2 inhibitor, approved for the treatment of type-2 diabetes mellitus (T2DM), is metabolized by uridine diphosphate-glucuronosyltransferases (UGT) 1A9 and UGT2B4, and is a substrate of P-glycoprotein (P-gp). Canagliflozin exposures may be affected by coadministration of drugs that induce (e.g., rifampin for UGT) or inhibit (e.g. probenecid for UGT; cyclosporine A for P-gp) these pathways. The primary objective of these three independent studies (single-center, open-label, fixed-sequence) was to evaluate the effects of rifampin (study 1), probenecid (study 2), and cyclosporine A (study 3) on the pharmacokinetics of canagliflozin in healthy participants. METHODS: Participants received; in study 1: canagliflozin 300 mg (days 1 and 10), rifampin 600 mg (days 4-12); study 2: canagliflozin 300 mg (days 1-17), probenecid 500 mg twice daily (days 15-17); and study 3: canagliflozin 300 mg (days 1-8), cyclosporine A 400 mg (day 8). Pharmacokinetics were assessed at prespecified intervals on days 1 and 10 (study 1); on days 14 and 17 (study 2), and on days 2-8 (study 3). RESULTS: Rifampin decreased the maximum plasma canagliflozin concentration (Cmax) by 28% and its area under the curve (AUC) by 51%. Probenecid increased the Cmax by 13% and the AUC by 21%. Cyclosporine A increased the AUC by 23% but did not affect the Cmax. CONCLUSION: Coadministration of canagliflozin with rifampin, probenecid, and cyclosporine A was well-tolerated. No clinically meaningful interactions were observed for probenecid or cyclosporine A, while rifampin coadministration modestly reduced canagliflozin plasma concentrations and could necessitate an appropriate monitoring of glycemic control.