Warfarin In Rats Research Articles

Effects of Salvianolate Injection on the Pharmacodynamics and Pharmacokinetics of Warfarin in Rats In vivo

Background:: Both Salvianolate Injection and warfarin are widely prescribed in patients with cardiovascular diseases, but the interaction between them is unknown and needs to be investigated. Objective:: This research aims to study the effects and mechanism of Salvianolate Injection on the pharmacodynamics and pharmacokinetics of warfarin in rats. Methods:: Male Wistar rats were intraperitoneally injected Salvianolate Injection (18 mg/kg) with or without oral administration of warfarin (0.2 mg/kg). A coagulation analyzer evaluated prothrombin time (PT) and activated partial thromboplastin time (APTT). International normalized ratio (INR) was calculated based on PT. UPLC-MS/MS combined with a chiral column was used to separate and measure the plasma concentration of R-warfarin and S-warfarin. Agilent SB-C18 column (1.8 μm, 2.1 mm × 50 mm) was used for separation, column temperature at 20°C. The isocratic mobile phase was acetonitrile-aqueous ammonium acetate (5 mM, pH 4) at a flow rate of 0.2 mL/min and 11.5 min for each injection. Pharmacokinetic parameters were calculated using DAS 2.0 software. Results:: Salvianolate Injection increased PT and INR (p < 0.05), while APTT was unaffected (p > 0.05). Compared with the warfarin group, the co-administration of Salvianolate Injection and singledose warfarin enlarged PT and INR (p < 0.05). Similar increases in pharmacokinetic parameters of R-warfarin and S-warfarin, including Cmax, AUC0-t, AUC0-∞, t1/2, and CL/F (p < 0.05), were observed in the co-administration group. A steady-state study of warfarin indicated that PT and INR in the coadministration group are longer than those in the warfarin group (p < 0.05). On days 7th and 8th of warfarin treatment (two and three days after Salvianolate Injection treatment), the plasma concentration of R-warfarin increased by 47.22% and 50.16% (p < 0.05), and plasma concentration of Swarfarin increased by 32.39% and 45.99% (p < 0.05), respectively. Conclusion:: Salvianolate Injection exhibits an anticoagulation effect in rats. Salvianolate Injection can enhance the anticoagulant effect of warfarin by slowing metabolism and increasing the concentration of both enantiomers. These results suggest that the combination of Salvianolate Injection and warfarin should be avoided or closely monitored in case of increasing bleeding risk.

Mechanism of Panax notoginseng saponins modulation of miR-214-3p/NR1I3 affecting the pharmacodynamics and pharmacokinetics of warfarin

BackgroundWith the prevalence of dietary supplements, the use of combinations of herbs and drugs is gradually increasing, together with the risk of drug interactions. In our clinical work, we unexpectedly found that the combination of Panax notoginseng and warfarin, which are herbs that activate blood circulation and remove blood stasis, showed antagonistic effects instead. The purpose of this study was to evaluate the drug interaction between Panax notoginseng saponins (PNS) and warfarin, the main active ingredient of Panax notoginseng, and to explore the interaction mechanism. MethodsThe effects and mechanisms of PNS on the pharmacodynamics and pharmacokinetics of warfarin were explored mainly in Sprague–Dawley rats and HepG2 cells. Elisa was used to detect the concentrations of coagulation factors, HPLC-MS to detect the blood concentrations of warfarin in rats, immunoblotting was employed to examine protein levels, qRT-PCR to detect mRNA levels, cellular immunofluorescence to detect the localization of NR1I3, and dual luciferase to verify the binding of miR-214-3p and NR1I3. ResultsPNS significantly accelerated warfarin metabolism and reduced its efficacy, accompanied by increased expression of NR1I3 and CYP2C9. Interference with NR1I3 rescued the accelerated metabolism of warfarin induce by PNS co-administration. In addition, we demonstrated that PNS significantly reduced miR-214-3p expression, whereas miR-214-3p overexpression reduced NR1I3 and CYP2C9 expression, resulting in a weakened antagonistic effect of PNS on warfarin. Additionally, we found that miR-214-3p bound directly to NR1I3 3′-UTR and significantly downregulated NR1I3 expression. ConclusionOur study demonstrated that PNS accelerates warfarin metabolism and reduces its pharmacodynamics by downregulating miR-214-3p, leading to increased expression of its target gene NR1I3, these findings provide new insights for clinical drug applications to avoid adverse effects.

Effects of sodium ferulate for injection on anticoagulation of warfarin in rats in vivo

BackgroundHerb-drug interactions may result in increased adverse drug reactions or diminished drug efficacy, especially for drugs with a narrow therapeutic index such as warfarin. The current study investigates the effects of sodium ferulate for injection (SFI) on anticoagulation of warfarin from aspects of pharmacodynamics and pharmacokinetics in rats and predicts the risk of the combination use.MethodsRats were randomly divided into different groups and administered single- or multiple-dose of warfarin (0.2 mg/kg) with or without SFI of low dose (8.93 mg/kg) or high dose (26.79 mg/kg). Prothrombin time (PT) and activated partial thromboplastin time (APTT) were detected by a blood coagulation analyzer, and international normalized ratio (INR) values were calculated. UPLC-MS/MS was conducted to measure concentrations of warfarin enantiomers and pharmacokinetic parameters were calculated by DAS2.0 software.ResultsThe single-dose study demonstrated that SFI alone had no effect on coagulation indices, but significantly decreased PT and INR values of warfarin when the two drugs were co-administered (P < 0.05 or P < 0.01), while APTT values unaffected (P > 0.05). Cmax and AUC of R/S-warfarin decreased but CL increased significantly in presence of SFI (P < 0.01). The multiple-dose study showed that PT, APTT, INR, and concentrations of R/S-warfarin decreased significantly when SFI was co-administered with warfarin (P < 0.01). Warfarin plasma protein binding rate was not significantly changed by SFI (P > 0.05).ConclusionsThe present study implied that SFI could accelerate warfarin metabolism and weaken its anticoagulation intensity in rats.

Safflower yellow for injection enhances anti-coagulation of warfarin in rats: implications in pharmacodynamics and pharmacokinetics

This study investigated whether Safflower Yellow for injection (SYI) would affect the anticoagulation of warfarin in rats. Wistar male rats were divided into six groups randomly and administered with SYI (9 mg/kg, intraperitoneal injection) in single-dose and steady-dose warfarin (0.2 mg/kg, oral gavage), respectively. The pharmacodynamic parameters of PT and APTT were measured by a coagulation analyser. R/S-warfarin concentration was measured by UHPLC-MS/MS, and pharmacokinetic parameters calculated using DAS 2.0 software. The single-dose study demonstrated that SYI, alone or co-administered with warfarin, could significantly increase PT, INR, and APTT values (p < 0.01). R-warfarin C max, AUC, and t 1/2 values increased by 9.25% (p > 0.05), 25.96% (p < 0.01), and 26.17% (p < 0.01), respectively, whereas the CL/F value reduced by 22.22% (p < 0.01) in the presence of SYI. Meanwhile, S-warfarin C max, AUC, and t 1/2 values increased by 37.41%, 32.11%, and 31.73% (all p < 0.01), respectively, whereas the CL/F value reduced by 33.33% (p < 0.01). The steady-dose study showed that PT, INR, APTT, and the concentrations of R/S-warfarin increased significantly when SYI was co-administered with warfarin (p < 0.01). SYI can enhance warfarin’s anticoagulation intensity and decelerate its metabolism in rats.

Effect of High Altitude Environment on Pharmacokinetic and Pharmacodynamic of Warfarin in Rats.

High altitude environment affects the pharmacokinetic (PK) parameters of drugs and the PK parameters are an important theoretical basis for guiding the rational clinical use of drugs. Warfarin is an oral anticoagulant of the coumarin class commonly used in clinical practice, but it has a narrow therapeutic window and wide individual variation. However, the effect of high altitude environment on PK and pharmacodynamic (PD) of warfarin is unclear. The objective of this study is to investigate the effect of a high altitude environment on PK and PD of warfarin in rats. Rats were randomly divided into plain group and high altitude group and blood samples were collected through the orbital venous plexus after administration of 2 mg/kg warfarin. Warfarin concentrations in plasma samples were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and PK parameters were calculated by the non-compartment model using WinNonlin 8.1 software. Meanwhile, the expression of PXR, P-gp and CYP2C9 in liver tissues was also determined by western blotting. The effect of high altitude environment on PD of warfarin was explored by measuring activated partial thromboplastin time (APTT) and prothrombin time (PT) values and then calculated international normalized ratio (INR) values based on PT. Significant changes in PK behaviors and PD of warfarin in high altitude-rats were observed. Compared with the plain-rats, the peak concentration (Cmax) and the area under the plasma concentration-time curve (AUC) increased significantly by 50.9% and 107.46%, respectively. At the same time, high altitude environment significantly inhibited the expression of PXR, P-gp and CYP2C9 in liver tissues. The results of the PD study showed that high altitude environments significantly prolonged PT, APTT and INR values. High altitude environment inhibited the metabolism and increased the absorption of warfarin in rats and increased the effect of anticoagulant effect, suggesting that the optimal dose of warfarin for patients at high altitude should be reassessed.

Influence of Quercetin Pretreatment on Pharmacokinetics of Warfarin in Rats.

Warfarin (WAR) is an anticoagulant with a narrow therapeutic index and is principally metabolized by CYP3A4 and CYP2C9 enzymes. The inhibitors of these enzymes may alter the systemic exposure to WAR. Quercetin (QUE), a bioflavonoid, may modify the bioavailability of drugs used concurrently by inhibiting CYP3A4, CYP2C8, CYP2C9, CYP1A2, and Pglycoprotein (P-gp). The current study scrutinized the influence of QUE on WAR pharmacokinetics in rats. QUE was orally administered to animals for 14 consecutive days, followed by WAR as a single oral dose on the 15th day in the pre-treatment group. The co-administration group received a single dose of QUE and WAR concomitantly. Only carboxymethylcellulose (CMC) 0.5% was administered as a vehicle to control group. In the pre-treated group, WAR's Cmax was increased by 30.43%, AUC0-∞ by 62.94%, and t1/2 by 10.54%, while Cl decreased by 41.35%, relative to control. In co-administered animals, WAR's Cmax increased by 10.98%, AUC0-∞ by 20.20%, and t1/2 by 8.87%, while Cl declined by 16.40%. QUE alters the pharmacokinetics of WAR, warranting possibly WAR dose adjustment after confirmatory clinical investigations, specifically in patients with thrombotic disorders and a pre-treatment history of QUE or its product.

Effects of Enteral Formulas and Their Food Protein and Dietary Fiber Components on Postprandial Plasma Warfarin Concentration in Rats

The purpose of this study was to clarify the effects of enteral formulas and their food protein and dietary fiber components on the pharmacokinetics of warfarin in rats. Blood samples were collected from 0 to 30 h after the oral administration of 0.5 mg/kg warfarin with or without an enteral formula (Mei Balance R®, Mei Flow®, F2 Light®, or PG Soft EJ®), food protein (milk protein or casein), or dietary fiber (indigestible dextrin or carrageenan). Plasma warfarin concentration was determined by liquid chromatography-tandem mass spectrometry. Plasma warfarin concentration was lower at the initial phase after co-administration of F2 Light®, milk protein, or casein compared with the control group, which might have been caused by the suppression of the gastrointestinal absorption of warfarin in accordance with the binding to food protein. Plasma warfarin concentration was significantly higher after co-administration of Mei Flow®, indigestible dextrin, or carrageenan compared with the control group. This is the first study to find that the plasma concentration of warfarin increases when warfarin is co-administered with enteral formula Mei Flow® or their dietary fiber components such as indigestible dextrin or carrageenan. Therefore, close attention should be paid to decreases or increases in the plasma warfarin concentration when warfarin is used with enteral formula.

The Effect of Wheatgrass Lyophilizate on Blood Clotting Time in Rats

Wheatgrass is widely used in the alternative medicine, however, there is a lack of clinical evidence to support its efficacy. Although based on its chemical composition, data from animal experiments and clinical trials, the use of juice and extracts of Triticum shoots seems to be safe, clinical reports point out its potential interaction with oral anticoagulants. The aim of our study was to assess the interaction of wheatgrass with warfarin in rats and to assess its flavonoid content. Three groups of animals were treated orally with wheatgrass, warfarin, or the combination of wheatgrass and warfarin for five days. Clotting assays were performed using platelet-poor plasma. Prothrombin time was determined by optical and mechanical coagulometers. Flavonoid content of wheatgrass was measured by HPLC. The effect of wheatgrass on prothrombin time was not confirmed. Co-administration of wheatgrass and warfarin did not result in diminished anticoagulant activity. Low amount of flavonoids was detected in wheatgrass juice, the total flavonoid content was 0.467 mg/100 g lyophilized juice powder. The previously reported rutin, quercetin and apigenin was not detected by us. Our results do not confirm the probability of interaction of wheatgrass with oral anticoagulants. However, the low flavonoid content of wheatgrass does not support its use as an antioxidant.

The influence of Javanese turmeric (Curcuma xanthorrhiza) on the pharmacokinetics of warfarin in rats with single and multiple-dose studies

Context Co-administration between warfarin (WF) and Curcuma xanthorrhiza Roxb. (Zingiberaceae) (CX) is found in Indonesian patients and need to be evaluated. Objective This study assesses the effect of concomitant administration of CX extract on the pharmacokinetics of WF in rats. Materials and methods Wistar rats were divided into 4 groups (n = 6) and administered with 2% Pulvis Gummi Arabicum (PGA, control), fluconazole (FZ, 6 mg/kg), CX-1 (6 mg/kg) or CX-2 (18 mg/kg BW) for 7 days. For the single-dose study, at the 8th day, WF (1 mg/kg) was administered to all groups and blood samples were taken from 0.25 to 72 h. For the multiple-dose study, daily dose of WF was administered to all groups of rats and at the 7th to 9th day, the rats were treated with PGA, CX-1, CX-2 and FZ. Blood samples were withdrawn daily at 4 h after administration of WF from the 1st to 11th day. Results The area under the curve (AUC) of R- and S-WF in the CX-2 group was a significantly higher value compared to the control (77.54 vs. 35.27 mg.h/L for R-WF and 316.26 vs. 40.16 mg.h/L for S-WF; p < 0.05; Kruskal-Wallis method). The CX-2 administration also caused the increasing in the concentration level of R-WF (16%) and S-WF (27%) from the 7th to 9th day of administration. Discussion and Conclusions The CX administration in a higher dose caused alteration on WF pharmacokinetics suggesting the need for clinical evaluation of the interaction between CX and WF.

Effects of Herba Erigerontis injection on pharmacodynamics and pharmacokinetics of warfarin in rats in vivo.

Herba Erigerontis injection (HEI) is an aqueous solution derived from whole plants of Erigeron breviscapus, which may be co-administered with warfarin to treat cardiovascular and cerebrovascular disorders. This research was conducted to make sure whether HEI would affect anticoagulation of warfarin to guarantee reasonable medication. The pharmacodynamic study was designed to measure prothrombin time (PT) and activated partial thromboplastin time (APTT) values, and international normalized ratio (INR) values were calculated. For pharmacokinetic study, ultra performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) technology was applied to measure plasma concentrations of warfarin enantiomers. The influence of HEI on plasma protein binding rate of warfarin was assessed by ultrafiltration. Pharmacodynamic study demonstrated that both HEI alone and co-administered with warfarin could increase PT and INR values significantly (P<.01), whereas the APTT values were unaffected (P>.05). Pharmacokinetic study manifested that Cmax , AUC and t1/2 prolonged significantly (P<.01) for R/S-warfarin in presence of HEI. Low (3.6mL/kg), medium (7.2mL/kg) and high (10.8mL/kg) doses of HEI could decrease plasma protein binding rate of warfarin significantly (P<.01). The results mean that HEI can potentiate the anticoagulant response of warfarin through both pharmacodynamics and pharmacokinetics.

Effects of Xiangdan Injection on pharmacokinetics and pharmacodynamics of warfarin in rats in vivo

This study is to explore the effect of Xiangdan Injection on anticoagulation of warfarin in rats. Rats were randomly divided into different groups and then administered, subsequently the blood samples were collected at a set series of time points to measure PT(prothrombin time) and APTT(activated partial thromboplastin time) values, and INR(international normalized ratio) value was calculated. The plasma concentrations of warfarin enantiomers were determined by UPLC-MS/MS technology, and pharmacokinetic parameters were calculated by DAS 2.0 software. Statistical analysis was performed to compare differences between the groups. Single-dose study of warfarin showed that Xiangdan Injection alone had no effects on PT, APTT and INR, but when co-administrated with warfarin, PT and INR values were increased(P&lt;0.01), while APTT was unaffected; after co-administration of the two drugs, C_(max), AUC_(0-t), and AUC_(0-∞) of S-warfarin increased(P&lt;0.01), and t_(1/2) prolonged(P&lt;0.01), while the pharmacokinetic parameters of R-warfarin were not changed significantly. Steady-state study of warfarin showed that after co-administration of the two drugs, the PT and INR values increased(P&lt;0.05), and the plasma concentration of S-warfarin increased(P&lt;0.01), while the plasma concentration of R-warfarin was not changed significantly. The results suggest that Xiangdan Injection itself has no effect on coagulation index, but can enhance the anticoagulant effect of warfarin by slowing metabolism of S-warfarin.

Piperine Alters the Pharmacokinetics and Anticoagulation of Warfarin in Rats.

IntroductionPiperine, the bioactive compound of black pepper, and warfarin are metabolized by cytochrome P450 enzymes and are both highly plasma protein-bound compounds. In this study, we evaluated the effect of co-administered piperine on the pharmacokinetics and anticoagulation of warfarin in rats.MethodsWe studied four Sprague-Dawley rat groups: a negative control group receiving only oral warfarin, a test group receiving warfarin plus piperine, a positive control group receiving warfarin plus sulfaphenazole (CYP2C inhibitor), and another positive control group receiving warfarin plus ketoconazole (CYP3A inhibitor). We also analyzed plasma concentrations of warfarin and its major metabolite, 7-hydoxywarfarin. Blood clotting time, calculated as international normalized ratio (INR), was also measured.ResultsOur results showed that although co-administration of piperine produced a non-significant decrease in warfarin concentrations, it resulted in significantly lower 7-hydroxywarfarin metabolite concentrations. Piperine significantly decreased, by sixfold, AUC0–∞, by eightfold, Cmax, but significantly increased, by fivefold, CL/F and, by sixfold, Vd/F of 7-hydroxywarfarin. The INR values were consistent with the decrease in warfarin concentration in the presence of piperine and showed a significant decrease at 24 h after warfarin dose.ConclusionWe conclude that piperine could be a potent inhibitor of cytochrome P450 metabolism of warfarin in vivo and, contrary to the expectation, may reduce the plasma concentration and anticoagulation of warfarin. This interaction could have a clinical significance and should be investigated in patients.

Effects of sulfotanshinone sodium injection on the pharmacokinetics and pharmacodynamics of warfarin in rats in vivo

This study was to explore the effects of sulfotanshinone sodium injection (SSI) on the pharmacokinetics and pharmacodynamics of warfarin in rats.The studies of single dose and multiple dose of warfarin were designed to assess the interaction between warfarin and SSI. Rats were divided into different groups randomly and administered with warfarin in the absence or presence of SSI. Prothrombin time (PT) and activated partial thromboplastin time (APTT) values were detected by blood coagulation analyzer, and international normalized ratio (INR) values were calculated. Plasma concentrations of warfarin enantiomers were determined by UPLC–MS/MS method, pharmacokinetic parameters were calculated.The single-dose study demonstrated that the repeated doses of SSI alone had no effect on PT, APTT and INR values, but had a significant effect on PT and INR values produced by a single dose of warfarin, APTT values were unaffected. The Cmax, AUC of R-warfarin and S-warfarin were reduced, t1/2 were shortened. The multiple-dose study showed that PT, APTT, INR values, and the Cmax and AUC of R-warfarin and S-warfarin decreased significantly after administration of SSI.The finding implied that SSI could accelerate warfarin metabolism and weaken its anticoagulation. However, human SSI–warfarin interaction studies need to be conducted to confirm this finding.

Influence of glycyrrhetinic acid on the pharmacokinetics of warfarin in rats

1. Combination of different drugs has been widely applied in clinics in China. Both glycyrrhetinic acid (GA) and warfarin possess various pharmacological activities, the co-administration of them is becoming popular. However, the herb–drug interaction between GA and warfarin is still unknown.2. The herb–drug interaction between GA and warfarin in vivo and in vitro was studied, to clarify the effect of GA on the pharmacokinetics of warfarin and its main mechanism.3. The pharmacokinetics of intragastric administered warfarin (0.5 mg/kg) with or without GA pretreatment (100 mg/kg/day, 7 days) were investigated. The rat liver microsomes incubation systems were used to study the effect of GA on the metabolic stability of warfarin and support the in vivo pharmacokinetic data.4. The pharmacokinetic results indicated that co-administration of GA could increase the systemic exposure of warfarin, including area under the curve (48.87 ± 2.89 µg·h·mL−1 without GA versus 58.63 ± 1.90 µg·h·mL−1 with GA), maximum plasma concentration and t1/2. The metabolic stability of warfarin increased from 23.8 ± 5.9 to 41.4 ± 7.1 min with the pretreatment of GA.5. These results indicated that GA could change the pharmacokinetic profile of warfarin. The metabolism of warfarin was slowed down in rat liver and the systemic exposure increased by GA, via inhibiting the activity of CYP3A4.

Development and validation of an ultra-high-performance liquid chromatography-tandem mass spectrometry method to determine the bioavailability of warfarin and its major metabolite 7-hydroxy warfarin in rats dosed with oral formulations containing different polymorphic forms.

A simple, sensitive and rapid ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry method was developed and validated for the quantification of warfarin and 7-hydroxy warfarin in Sprague Dawley (SD) rats. Animals were administered a single dose of warfarin sodium formulations (crystalline and amorphous) at 12 mg/kg via oral gavage and blood was drawn over a 96-h time course. Sample process recoveries, matrix effect and analyte stability were determined. The linearity for warfarin and 7-hydroxy warfarin was from 5 to 2000 ng/mL in blank SD rat plasma. Correlation coefficients (r2 ) for standard calibration curves were >.98 and analytes quantified within ±15% of target at all calibrator concentrations. The average percent accuracy and precision for intra- and inter-day were 93.7%-113.8% and ≤12.1%, respectively, for warfarin and 7-hydroxy warfarin, across the quality control standards (5, 10, 500, 1800 and 2000 ng/mL). Acceptable analytical recovery (>55%) was achieved with process efficiencies >41.5% and matrix effects <139.9% over the analytical range. Both analytes were stable in stock solution, autosampler, benchtop and three cycles of freeze-thaw with percent accuracy ≥90.2% and precision (percent relative standard deviation) ≤14%. The validated method was successfully applied to a pre-clinical bioavailability study of crystalline and amorphous warfarin sodium formulations in SD rats.

Effects of CYP2C11 gene knockout on the pharmacokinetics and pharmacodynamics of warfarin in rats

1. CYP2C11 is the most abundant isoform of cytochrome P450s (CYPs) in male rats and is considered the main enzyme for warfarin metabolism.2. To further access the in vivo function of CYP2C11 in warfarin metabolism and efficacy, a CYP2C11-null rat model was used to study warfarin metabolism with both in vitro and in vivo approaches. Prothrombin time (PT) of warfarin was also determined.3. The maximum rate of metabolism (Vmax) and intrinsic clearance (CLint) of liver microsomes from CYP2C11-null males were reduced by 37 and 64%, respectively, compared to those in Sprague Dawley (S-D) rats. The Km of liver microsomes from CYP2C11-null males was increased by 73% compared to that of S-D rats. The time to reach the maximum plasma concentration (Tmax) of warfarin in CYP2C11-null males was significantly delayed compared to that in S-D males, and the CL rate was also reduced. The PT of CYP2C11-null rats was moderately longer than that of S-D rats.4. In conclusion, the clearance rate of warfarin was mildly decreased and its anticoagulant effect was moderately increased in male rats following CYP2C11 gene knockout. CYP2C11 played a certain role in the clearance and efficacy of warfarin, while it did not seem to be essential.

Influence of Flavonoids from Galium verum L. on the activities of cytochrome P450 isozymes and pharmacokinetic and pharmacodynamic of warfarin in rats

Background: Galium verum L., a traditional Chinese medicine, has been widely used in the folk in China. Preparations of G. verum L. were used to treat thromboembolic disease in clinic for many years and often combined with anticoagulants. Flavonoids from G. verum L. (FGVL) are the main active component. Materials and Methods: We assessed the potential influence of FGVL on the activities of five cytochrome P450 (CYP) enzymes and on the pharmacokinetic of warfarin in rats. The pharmacokinetics of five probe drugs and of warfarin was compared between control and FGVL-pretreated groups, which could estimate the effect on the activities of the five isozymes and warfarin metabolism. Moreover, the potential influence of FGVL on the pharmacodynamic of warfarin was investigated. Results: There was no significant difference in the pharmacokinetic parameters of chlorzoxazone and midazolam between control and FGVL-pretreated groups. However, the pharmacokinetic parameters of caffeine in every dose, metoprolol in middle dose, and tolbutamide in high dose were affected significantly (P < 0.05). It indicated that the metabolism of caffeine was markedly faster in FGVL-pretreated group but metoprolol in the middle dose and tolbutamide in the high-dose FGVL-pretreated group were markedly slower. The anticoagulation of combination group is better than warfarin group or FGVL group. This suggested that FGVL showed no effect on the enzyme activities of CYP2E1 and CYP3A2, induced the enzyme activities of CYP1A2, but inhibited the enzyme activities of CYP2D4 in the middle dose and CYP2C11 in high dose. Conclusion: This indicates that FGVL may increase the anticoagulation of warfarin in clinic dose. The dose of warfarin should be adjusted when combined with FGVL or preparations of G. verum L.

Influence of andrographolide on the pharmacokinetics of warfarin in rats

Context: Andrographolide and warfarin are often used together in clinics in China. However, the herb-drug interaction between andrographolide and warfarin is still unknown.Objective: This study investigates the herb-drug interaction between andrographolide and warfarin in vivo and in vitro.Materials and methods: A sensitive and reliable LC-MS/MS method was developed for the determination of warfarin in male Sprague-Dawley rats plasma, and then the pharmacokinetics of orally administered warfarin (0.5 mg/kg) with or without andrographolide (30 mg/kg/day for 7 days) pretreatment was investigated. In addition, Sprague-Dawley rat liver microsomes incubation systems were used to support the in vivo pharmacokinetic data and investigate its potential mechanism.Results: The method validation results showed that a sensitive and reliable LC-MS/MS method was developed for the determination of warfarin in rat plasma samples. The pharmacokinetic results indicated that co-administration of andrographolide could increase the systemic exposure of warfarin significantly, including area under the curve (118.92 ± 18.08 vs. 60.58 ± 9.46 μg × h/mL), maximum plasma concentration (3.32 ± 0.41 vs. 2.35 ± 0.25 μg/mL) and t1/2 (22.73 ± 3.28 vs. 14.27 ± 2.67 h). Additionally, the metabolic stability of warfarin increased from 23.5 ± 4.7 to 38.7 ± 6.1 min with the pretreatment of andrographolide, and the difference was significant (p < 0.05).Discussion and conclusion: In conclusion, andrographolide could increase the systemic exposure of warfarin in rats when andrographolide and warfarin were co-administered, and possibly by slowing down the metabolism of warfarin in rat liver by inhibiting the activity of CYP3A4 or CYP2C9.

Influence of Shenxiong Glucose Injection on the Activities of Six CYP Isozymes and Metabolism of Warfarin in Rats Assessed Using Probe Cocktail and Pharmacokinetic Approaches

Shenxiong glucose injection (SGI), a traditional Chinese medicine (TCM) preparation, has been widely used for the treatment of various cardiovascular and cerebrovascular diseases for many years. We assessed the potential influences of SGI on the activities of six CYP enzymes (CYP1A2, CYP2C11, CYP2C19, CYP2D4, CYP2E1, and CYP3A2) and on the pharmacokinetics of warfarin in rats. We compared plasma pharmacokinetics of six probe drugs (caffeine/CYP1A2, tolbutamide/CYP2C11, omeprazole/CYP2C19, metoprolol/CYP2D4, chlorzoxazone/CYP2E1, and midazolam/CYP3A2) and of warfarin between control and SGI-pretreated groups, to estimate the effect on the relative activities of the six isozymes and warfarin metabolism. There were no significant differences in the pharmacokinetic parameters of caffeine, omeprazole, metoprolol, chlorzoxazone, and midazolam between the SGI-pretreated and control groups. However, many pharmacokinetic parameters of tolbutamide in SGI-pretreated rats were affected significantly (p < 0.05), and indicated tolbutamide metabolism in the former group was markedly slower. Moreover, SGI reduced the clearance of warfarin. These results suggested SGI showed no effects on the enzyme activities of rat CYP1A2, CYP2C19, CYP2D4, CYP2E1, and CYP3A2, but inhibited the enzyme activity of CYP2C11, and improved the blood concentration of warfarin. This suggests that the dose of warfarin may need be adjusted when co-administrated with SGI.

Effects of safflower injection on the pharmacodynamics and pharmacokinetics of warfarin in rats

1. Safflower injection (SI) is extracted from Chinese herbal medicine safflower that comprises many active components. Warfarin is a common anticoagulant and has exhibited drug interactions with several herbal products. This study aimed to investigate the effects of SI on pharmacodynamics and pharmacokinetics of warfarin in rats.2. Wistar rats were randomly divided into blank control group, SI group, warfarin control group and SI + warfarin group, respectively. In SI and SI + warfarin groups, rats were injected with SI (1.6 mL/kg/d, i.p.) for 14 days. Warfarin (0.2 mg/kg) was given orally on the eighth day. Saline was given as control. The blood samples were collected at various time points. Prothrombin time (PT) and activated partial thromboplastin time (APTT) were measured. UPLC-MS/MS was used to determine the plasma concentrations of S(R)-warfarin, and the pharmacokinetic parameters were calculated.3. PT, APTT in SI and SI + warfarin rats increased significantly compared with corresponding control rats. The pharmacokinetic parameters including Cmax, t1/2, AUC0-t and AUC0-∞ of S-warfarin and R-warfarin in SI + warfarin rats were higher than those in warfarin control rats.4. These findings suggest that SI significantly increases the anticoagulant effect of warfarin by affecting its pharmacodynamic and pharmacokinetic parameters.