Routine Use of Tenecteplase for Thrombolysis in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: In ischemic stroke, intravenous tenecteplase is noninferior to alteplase in selected patients and has some practical advantages. Several stroke centers in New Zealand changed to routine off-label intravenous tenecteplase due to improved early recanalization in large vessel occlusion, inconsistent access to thrombectomy within stroke networks, and for consistency in treatment protocols between patients with and without large vessel occlusion. We report the feasibility and safety outcomes in tenecteplase-treated patients. METHODS: We performed a retrospective analysis of consecutive patients thrombolyzed with intravenous tenecteplase at 1 comprehensive and 2 regional stroke centers from July 14, 2018, to February 29, 2020. We report the baseline clinical characteristics, rates of symptomatic intracranial hemorrhage, and angioedema. These were then compared with patient outcomes with those treated with intravenous alteplase at 2 other comprehensive stroke centers. Multivariable mixed-effects logistic regression models were performed assessing the association of tenecteplase with symptomatic intracranial hemorrhage and independent outcome (modified Rankin Scale score, 0-2) at day 90. RESULTS: There were 165 patients treated with tenecteplase and 254 with alteplase. Age (75 versus 74 years), sex (56% versus 60% male), National Institutes of Health Stroke Scale scores (8 versus 10), median door-to-needle times (47 versus 48 minutes), or onset-to-needle time (129 versus 130 minutes) were similar between the groups. Symptomatic intracranial hemorrhage occurred in 3 (1.8% [95% CI, 0.4-5.3]) tenecteplase patients compared with 7 (2.7% [95% CI, 1.1-5.7]) alteplase patients (P=0.75). There were no differences between tenecteplase and alteplase in the rates of angioedema (4 [2.4%; 95% CI, 0.7-6.2] versus 1 [0.4%; 95% CI, 0.01-2.2], P=0.08) or 90-day functional independence (100 [61%] versus 140 [57%], P=0.47), respectively. In mixed-effects logistic regression models, there was no significant association between thrombolytic choice and symptomatic intracranial hemorrhage (odds ratio tenecteplase, 0.62 [95% CI, 0.14-2.80], P=0.53) or functional independence (odds ratio tenecteplase, 1.20 [95% CI, 0.74-1.95], P=0.46). CONCLUSIONS: Routine use of tenecteplase for stroke thrombolysis was feasible and had comparable safety profile and outcome to alteplase.

Golden Age of Fluorenylidene Phosphaalkenes-Synthesis, Structures, and Optical Properties of Heteroaromatic Derivatives and Their Gold Complexes.

The substitution of 2,7-dibromo-9-fluorenyl phosphaalkenes with heteroaromatic substituents (bithiophene, benzothiophene, pyridine) offers access to interesting push-pull dye molecules. Steric shielding due to the bulky P-substituent gives marked different reactivities at the 2- and 7-positions, allowing the synthesis of mixed/asymmetric derivatives. Further functionalization via gold(I) coordination was demonstrated and increased the acceptor character, concomitant with a red-shifted absorption.

Comparison of the Magnetic and Structural Properties of MnFePSi Microwires and MnFePSi Bulk Alloy.

We provide comparative studies of the structural, morphological, microstructural, and magnetic properties of MnFePSi-glass-coated microwires (MnFePSi-GCMWs) and bulk MnFePSi at different temperatures and magnetic fields. The structure of MnFePSi GCMWs prepared by the Taylor-Ulitovsky method consists of the main Fe2P phase and secondary impurities phases of Mn5Si3 and Fe3Si, as confirmed by XRD analysis. Additionally, a notable reduction in the average grain size from 24 µm for the bulk sample to 36 nm for the glass-coated microwire sample is observed. The analysis of magnetic properties of MnFePSi-glass-coated microwires shows different magnetic behavior as compared to the bulk MnFePSi. High coercivity (450 Oe) and remanence (0.32) are observed for MnFePSi-GCMWs compared to low coercivity and remanent magnetization observed for bulk MnFePSi alloy. In addition, large irreversibility at low temperatures is observed in the thermal dependence of magnetization of microwires. Meanwhile, the bulk sample shows regular ferromagnetic behavior, where the field cooling and field heating magnetic curves show a monotonic increase by decreasing the temperature. The notable separation between field cooling and field heating curves of MnFePSi-GCMWs is seen for the applied field at 1 kOe. Also, the M/M5K vs. T for MNFePSi-GCMWs shows a notable sensitivity at a low magnetic field compared to a very noisy magnetic signal for bulk alloy. The common features for both MnFePSi samples are high Curie temperatures above 400 K. From the experimental results, we can deduce the substantial effect of drawing and quenching involved in the preparation of glass-coated MnFePSi microwires in modification of the microstructure and magnetic properties as compared to the same bulk alloy. The provided studies prove the suitability of the Taylor-Ulitovsky method for the preparation of MnFePSi-glass-coated microwires.

Microfluidic Processing of Piezoelectric and Magnetic Responsive Electroactive Microspheres.

Poly(vinylidene fluoride) (PVDF) combined with cobalt ferrite (CFO) particles is one of the most common and effective polymeric magnetoelectric composites. Processing PVDF into its electroactive phase is a mandatory condition for featuring electroactive behavior and specific (post)processing may be needed to achieve this state, although electroactive phase crystallization is favored at processing temperatures below 60 °C. Different techniques are used to process PVDF-CFO nanocomposite structures into microspheres with high CFO dispersion, with microfluidics adding the advantages of high reproducibility, size tunability, and time and resource efficiency. In this work, magnetoelectric microspheres are produced in a one-step approach. We describe the production of high content electroactive phase PVDF and PVDF-CFO microspheres using microfluidic technology. A flow-focusing polydimethylsiloxane device is fabricated based on a 3D printed polylactic acid master, which enables the production of spherical microspheres with mean diameters ranging from 80 to 330 µm. The microspheres feature internal and external cavernous structures and good CFO distribution with an encapsulation efficacy of 80% and prove to be in the electroactive γ-phase with a mean content of 75%. The microspheres produced using this approach show suitable characteristics as active materials for tissue regeneration strategies and other piezoelectric polymer applications.

Music in the Operating Room: Comparing the Opinions of Surgeons, Anesthesiologists, and Nurses.

BACKGROUND: Music is part of operating room (OR) culture; however, some personnel may perceive music as a distraction. METHODS: A single institution survey of surgeons (SURG), anesthesia (ANES), and nursing (NURS) regarding attitudes on music in the OR. RESULTS: There were 222 responses (67% response rate) agreeing that music in the OR should be allowed (91%), is calming (75%), and helps with focus (63%). Most did not feel music was distracting (63%) or unsafe (80%). SURG were more likely to state that surgeons should decide (46.7%) if music should be played, whereas ANES and NURS (81%) were more likely to feel decisions should be made collaboratively (P < .001). CONCLUSION: Most OR personnel feel positively towards music. Surgeons were more likely to believe the decision to play music should be the surgeon's choice. The majority of OR staff agreed with collaborative decision-making, aligning with creating a safe OR culture.

Electro and magnetoactive printed bi-functional actuators based on alginate hybrid hydrogels.

Soft materials are attracting much attention for the development of biostructures able to mimic the movement of natural systems by remote actuation. Multi-sensitive hydrogels are among the best materials for obtaining dynamic and biocompatible soft structures for soft actuators and related biomedical devices. Nevertheless, bioinks based on naturally occurring and stimuli responsive hydrogels able to be 3D printed continues being a challenge for advanced applications. In this work 3D printable electrically and magnetically responsive, non-cytotoxic, hybrid hydrogels based on alginate and zero monovalent iron nanoparticles (NPs) are presented. The effect of NPs addition on the physico-chemical properties of the hydrogels is addressed, together with its effect on the functional electroactive and magnetoactive response. NPs concentration up to 10 % do not affect the mechanical stability of the gels, while promoting an increase actuation response.

APEX: a phase II randomised clinical trial evaluating the safety and preliminary efficacy of oral X-82 to treat exudative age-related macular degeneration.

PURPOSE: The safety and efficacy of X-82, an orally administered inhibitor of vascular endothelial growth factor (VEGF) and platelet-derived growth factor, was investigated for treatment of wet age-related macular degeneration (AMD) in a phase II clinical trial. METHODS: This phase II, randomised, double-masked, placebo-controlled trial enrolled subjects with a prior diagnosis of exudative AMD having received at least two intravitreal injections of anti-VEGF therapy. Subjects were randomised equally into four groups that received either daily 50mg, 100mg or 200mg dosages of X-82 or a placebo tablet. At each 4-week interval visit for 52 weeks, subjects were to be assessed to determine if rescue treatment was needed with anti-VEGF therapy. RESULTS: 157 patients were enrolled. Due to gastrointestinal and hepatobiliary adverse events and the fulfilment of the primary endpoint, the trial was stopped prematurely after a second interim analysis. The primary endpoint of non-inferiority of visual acuity compared with placebo was demonstrated in all groups receiving X-82 (p<0.001). There was a dose-dependent trend in the number of injections over a 52-week period, with the 50 mg (n=40), 100 mg (n=39), 200 mg (n=39) and placebo (n=39) group requiring 6.7, 6.0, 4.7 and 8.1 injections, respectively. CONCLUSIONS: X-82 oral therapy in combination with pro re nata anti-VEGF injections showed non-inferiority in visual acuity outcomes while achieving a dose-dependent decrease in the number of anti-VEGF injections compared with placebo. Given the limited tolerability and safety issues observed, X-82 does not have a sufficient benefit to risk profile in treatment of patients with AMD.

Multiple drug resistance in hookworms infecting greyhound dogs in the USA.

Ancylostoma caninum is the most prevalent nematode parasite of dogs. We confirmed multiple-drug resistance (MDR) in several A. caninum isolates to all anthelmintic drug classes approved for the treatment of hookworms in dogs in the USA. Cases of MDR hookworms appear to be highly overrepresented in greyhounds. The aims of this study were to evaluate the drug-resistant phenotypes and genotypes of the A. caninum infecting greyhounds. Fecal samples from greyhounds of the USA were acquired from two greyhound adoption kennels, one active greyhound racing kennel, and three veterinary practices. Fecal egg counts (FECs) were performed on fecal samples from 219 greyhounds, and despite treatment with anthelmintics, the mean FEC was 822.4 eggs per gram (EPG). Resistance to benzimidazoles and macrocyclic lactones were measured using the egg hatch assay (EHA) and the larval development assay (LDA), respectively. We performed 23 EHA and 22 LDA on either individual or pooled feces, representing 54 animals. Mean and median IC50 and IC95 values for the EHA were 5.3 µM, 3.6 µM, and 24.5 µM, 23.4 µM, respectively. For the LDA, the median IC50 value was >1000 nM. These values ranged 62-81 times higher than our susceptible laboratory isolate. Only post-treatment samples were available. For samples collected <10 days post-treatment with albendazole, moxidectin, or a combination of febantel-pyrantel-moxidectin, the mean FEC were 349, 333, and 835 EPG, respectively. We obtained DNA from hookworm eggs isolated from 70 fecal samples, comprised of 60 individual dogs and 10 pools. Deep sequencing of the isotype 1 ß-tubulin gene only revealed the presence of the F167Y (TTC>TAC) resistance polymorphism in 99% of these samples. These clinical, in vitro, and genetic data provide strong evidence that greyhound dogs in the USA are infected with MDR A. caninum at very high levels in prevalence and infection intensity.

The pharmacokinetics and pharmacodynamics of prasugrel in healthy Chinese, Japanese, and Korean subjects compared with healthy Caucasian subjects.

PURPOSE: Prasugrel is a novel thienopyridine prodrug metabolised to an active metabolite that binds irreversibly to the platelet P2Y(12) receptor and inhibits adenosine diphosphate (ADP)-induced platelet aggregation. We compared prasugrel pharmacokinetics, pharmacodynamics, and tolerability in healthy Chinese, Japanese, Korean and Caucasian subjects. METHODS: In an open-label, single-centre, parallel-design study, 89 healthy subjects (25 Chinese, 20 Japanese, 22 Korean and 22 Caucasian) aged 20-65 years were given a prasugrel 60-mg loading dose (LD) followed by daily 10-mg maintenance doses (MD) for 7 days and then 5-mg MD for 10 days. Plasma concentrations of prasugrel's active metabolite and inhibition of ADP-induced platelet aggregation (IPA) were determined. RESULTS: Mean exposure to prasugrel's active metabolite in all treatment regimens was higher in each of the Asian groups than in the Caucasian group, although there was considerable overlap between individual exposure estimates in Asians and Caucasians. The mean IPA was also higher in Asians than in Caucasians following a prasugrel 60-mg LD, although the difference did not consistently achieve statistical significance. Prasugrel 10-mg or 5-mg MD produced statistically significantly higher IPA in each Asian group compared with that in the Caucasians. Prasugrel was well tolerated during the LD and MD regimens by all groups. CONCLUSIONS: Mean exposure to the prasugrel active metabolite following prasugrel 60-mg LD and during daily 10-mg or 5-mg MD was higher in each of the Asian groups than in the Caucasian group, which resulted in greater platelet inhibition.

Birth of a Live Cria After Transfer of a Vitrified-Warmed Alpaca (Vicugna pacos) Preimplantation Embryo.

The alpaca (Vicugna pacos) is an important species for the production of fiber and food. Genetic improvement programs for alpacas have been hindered, however, by the lack of field-practical techniques for artificial insemination and embryo transfer. In particular, successful techniques for the cryopreservation of alpaca preimplantation embryos have not been reported previously. The objective of this study was to develop a field-practical and efficacious technique for cryopreservation of alpaca preimplantation embryos using a modification of a vitrification protocol originally devised for horses and adapted for dromedary camels. Four naturally cycling non-superovulated Huacaya females serving as embryo donors were mated to males of proven fertility. Donors received 30 µg of gonadorelin at the time of breeding, and embryos were non-surgically recovered 7 days after mating. Recovered embryos (n = 4) were placed individually through a series of three vitrification solutions at 20°C (VS1: 1.4 M glycerol; VS2: 1.4 M glycerol + 3.6 M ethylene glycol; VS3: 3.4 M glycerol + 4.6 M ethylene glycol) before loading into an open-pulled straw (OPS) and plunging directly into liquid nitrogen for storage. At warming, each individual embryo was sequentially placed through warming solutions (WS1: 0.5 M galactose at 37°C; WS2: 0.25 M galactose at 20°C), and warmed embryos were incubated at 37°C in 5% CO2 in humidified air for 20-22 h in 1 ml Syngro® holding medium supplemented with 10% (v/v) alpaca serum to perform an initial in vitro assessment of post-warming viability. Embryos whose diameter increased during culture (n = 2) were transferred individually into synchronous recipients, whereas embryos that did not grow (n = 2) were transferred together into a single recipient to perform an in vivo assessment of post-warming viability. Initial pregnancy detection was performed ultrasonographically 29 days post-transfer when fetal heartbeat could be detected, and one of three recipients was pregnant (25% embryo survival rate). On November 13, 2019, the one pregnant recipient delivered what is believed to be the world's first cria produced from a vitrified-warmed alpaca embryo.

Population pharmacokinetic analyses to evaluate the influence of intrinsic and extrinsic factors on exposure of prasugrel active metabolite in TRITON-TIMI 38.

Serial pharmacokinetic (PK) sampling in 1159 patients from TRITON-TIMI 38 was undertaken. A multilinear regression model was used to quantitatively predict prasugrel's active metabolite (Pras-AM) concentrations from its 2 downstream inactive metabolites. Population-based methods were then applied to Pras-AM concentration data to characterize the PK. The potential influence of body weight, body mass index, age, sex, renal function, diabetes, tobacco use, and other disease status on Bayesian estimates of Pras-AM exposures was assessed. The PK of Pras-AM was adequately described by a multicompartmental model and consistent with results from previous studies. The systemic exposure of prasugrel was not appreciably affected by body mass index, gender, diabetes, smoking, and renal impairment. Pras-AM mean exposure in patients weighing <60 kg (4.1%) was 30% (90% confidence interval [CI] 1.16-1.45) higher than exposure in patients > or =60 kg. Mean Pras-AM exposures for patients > or =75 years (10.5%) were 19% (90% CI: 1.11-1.28) higher compared with patients <75 years.

A comparison of the antiplatelet effects of prasugrel and high-dose clopidogrel as assessed by VASP-phosphorylation and light transmission aggregometry.

Platelet inhibition as measured by vasodilator-stimulated phosphoprotein (VASP) and light transmission aggregometry (LTA) have shown concordance following dosing of clopidogrel. No reports have directly compared the VASP assay and LTA at the levels of P2Y(12) blockade after loading doses (LDs) of prasugrel or high dose clopidogrel (600 and 900 mg). The aim was to compare the VASP assay and LTA during the loading dose phase of a comparative study of prasugrel and clopidogrel. Prasugrel 60 mg LD/10 mg maintenance dose (MD) and clopidogrel 300 mg/75 mg and 600 mg/75 mg LD/MD regimens were compared in a 3-way crossover study in 41 healthy, aspirin-free subjects. Each LD was followed by seven daily MDs and a 14-day washout period. P2Y(12) receptor blockade was estimated using the VASP assay, expressed as platelet reactivity index (VASP-PRI). Platelet aggregation was assessed by light transmission aggregometry (20 and 5 microM ADP). Twenty-four hours after prasgurel 60 mg or clopidogrel 300 mg and 600 mg, respectively, VASP-PRI decreased from approximately 80% to 8.9%, 54.7%, and 39.0%, and maximal platelet aggregation (MPA) decreased from approximately 79% to 10.8%, 42.7%, and 31.2%, with an overall VASP:MPA correlation of 0.88 (p < 0.01). VASP assay responses after the clopidogrel LDs showed a wider range of values (300 mg: 0-93%; 600 mg: 0-80%) than prasugrel (0-13%); MPA responses followed a similar trend. Pearson's correlation suggested a strong agreement between VASP and LTA (20 microM ADP) for MPA (r = 0.86, p < 0.0001). VASP and LTA demonstrated concordance across the response range of P2Y(12) receptor blockade following thienopyridine LDs.

The use of the VerifyNow P2Y12 point-of-care device to monitor platelet function across a range of P2Y12 inhibition levels following prasugrel and clopidogrel administration.

Variability in response to antiplatelet agents has prompted the development of point-of-care (POC) technology. In this study, we compared the VerifyNow P2Y12 (VN-P2Y12) POC device with light transmission aggregometry (LTA) in subjects switched directly from clopidogrel to prasugrel. Healthy subjects on aspirin were administered a clopidogrel 600 mg loading dose (LD) followed by a 75 mg/d maintenance dose (MD) for 10 days. Subjects were then switched to a prasugrel 60 mg LD and then 10 mg/d MD for 10 days (n = 16), or to a prasugrel 10 mg/d MD for 11 days (n = 19). Platelet function was measured by LTA and VN-P2Y12 at baseline and after dosing. Clopidogrel 600 mg LD/75 mg MD treatment led to a reduction in P2Y(12) reaction units (PRU) from baseline. A switch from clopidogrel MD to prasugrel 60 mg LD/10 mg MD produced an immediate decrease in PRU, while a switch to prasugrel 10 mg MD resulted in a more gradual decline. Consistent with the reduction in PRU, device-reported percent inhibition increased during both clopidogrel and prasugrel regimens. Inhibition of platelet aggregation as measured by LTA showed a very similar pattern to that found with VN-P2Y12 measurement, irrespective of treatment regimens. The dynamic range of VN-P2Y12 appeared to be narrower than that of LTA. With two different thienopyridines, the VN-P2Y12 device, within a somewhat more limited range, reflected the overall magnitude of change in aggregation response determined by LTA. The determination of the clinical utility of such POC devices will require their use in clinical outcome studies.

Evaluation of population pharmacokinetics and exposure-response relationship with coadministration of amlodipine besylate and olmesartan medoxomil.

Population pharmacokinetic models for amlodipine and olmesartan were developed using data collected from 4 phase I studies in healthy volunteers and 1 phase III study in subjects with mild to severe hypertension. A 2-compartment and a 1-compartment model best described the pharmacokinetics of olmesartan and amlodipine, respectively; both agents were characterized by first-order elimination/absorption and an absorption time lag. The analysis shows that neither agent had a clinically significant impact on the clearance of the other. The impact of covariates on the clearance of olmesartan and amlodipine was similar after coadministration of amlodipine besylate and olmesartan medoxomil as separate entities or as a fixed-dose combination compared with monotherapy. The effect of exposure to amlodipine and olmesartan on the change in trough seated diastolic blood pressure was best described by linear and maximum effect (E(max)) models, respectively. Black race was the most important covariate in the exposure-response model, decreasing the maximal possible effect of olmesartan on blood pressure while increasing the effect of amlodipine, without influencing pharmacokinetic parameters. The drug effect of combination therapy was defined on the basis of exposure to both compounds and was greater than the effect of monotherapy with either agent.

Model-based development of a PPARgamma agonist, rivoglitazone, to aid dose selection and optimize clinical trial designs.

A model-based approach was implemented for the development of the proliferator-activated receptor gamma (PPARgamma) agonist rivoglitazone. Population pharmacokinetic and pharmacodynamic models were developed using data collected from 2 phase I and 2 phase II studies in healthy volunteers and participants with type 2 diabetes mellitus. A 2-compartment model with first-order absorption and elimination and an absorption time lag best described rivoglitazone pharmacokinetics. Modified indirect-response models were used to characterize changes in fasting plasma glucose, HbA(1c), and hemodilution as a function of rivoglitazone plasma concentrations. In addition, differences in hemodilution among participants correlated with the incidence of edema. Current use of oral antidiabetic medication was a significant covariate for the fasting plasma glucose-HbA(1c) exposure-response model. Using a learn-and-confirm process, models developed prior to the second phase II study were able to make valid predictions for exposures and response variables in that study. In future studies, seamless designs can be supported by models such as those developed here.

Pharmacokinetics of amlodipine and olmesartan after administration of amlodipine besylate and olmesartan medoxomil in separate dosage forms and as a fixed-dose combination.

The pharmacokinetics of amlodipine and olmesartan in healthy volunteers after coadministration of amlodipine besylate and olmesartan medoxomil concomitantly as separate dosage forms and together in a fixed-dose combination tablet were characterized in 5 phase I, randomized, crossover studies. The mean steady-state pharmacokinetics of amlodipine and olmesartan were similar when olmesartan medoxomil 40 mg/day and amlodipine 10 mg/day were administered separately or concomitantly for 10 days. The total and maximum exposure to amlodipine and olmesartan after administration of fixed-dose combination amlodipine/olmesartan medoxomil 10 mg/40 mg was bioequivalent to amlodipine 10 mg plus olmesartan medoxomil 40 mg. The ratio of least squares mean and 90% confidence intervals for the area under the drug concentration-time curve from time zero to time t, from time zero to infinity, and the maximum observed plasma drug concentration of amlodipine and olmesartan fell within the prespecified range for bioequivalence (80.0% - 125.0%). The area under the drug concentration-time curve from time zero to time t, from time zero to infinity, and the maximum observed plasma drug concentration of both drugs also met the prespecified criterion for bioequivalence when the fixed-dose combination tablet was taken 30 minutes after a high-fat breakfast. Total exposure to amlodipine and olmesartan was dose-proportional after administration of olmesartan medoxomil 10 mg to 40 mg in the fixed-dose combination formulation with amlodipine 5 mg to 10 mg. From a pharmacokinetic perspective, the 2 drugs are well suited to coadministration in a fixed-dose combination.

Prasugrel, a new thienopyridine antiplatelet drug, weakly inhibits cytochrome P450 2B6 in humans.

Prasugrel, a thienopyridine prodrug, is hydrolyzed in vivo by esterases to a thiolactone followed by a single cytochrome P450 (CYP)-dependent step to an active metabolite that is a potent inhibitor of adenosine diphosphate-induced platelet aggregation. This open-label, multiple-dose, 2-period, fixed-sequence study assessed CYP2B6 inhibition by prasugrel using bupropion as a probe substrate, where its active metabolite, hydroxybupropion, is almost exclusively formed by CYP2B6. Thirty healthy subjects received a single 150-mg oral dose of sustained-release bupropion. After a 7-day washout, a 60-mg prasugrel loading dose, followed by a 10-mg daily maintenance dose for 10 days, was administered. Bupropion (150 mg) was given with prasugrel on day 7 of this phase. Prasugrel weakly inhibited CYP2B6 activity as it increased bupropion Cmax and AUC0-infinity by 14% and 18%, respectively, and decreased hydroxybupropion Cmax and AUC0-infinity by 32% and 23%. These results are consistent with patients receiving prasugrel not requiring dose adjustments when treated with drugs primarily metabolized by CYP2B6.

Effects of the proton pump inhibitor lansoprazole on the pharmacokinetics and pharmacodynamics of prasugrel and clopidogrel.

Prasugrel and clopidogrel, thienopyridine prodrugs, are each metabolized to an active metabolite that inhibits the platelet P2Y(12) ADP receptor. In this open-label, 4-period crossover study, the effects of the proton pump inhibitor lansoprazole on the pharmacokinetics and pharmacodynamics of prasugrel and clopidogrel were assessed in healthy subjects given single doses of prasugrel 60 mg and clopidogrel 300 mg with and without concurrent lansoprazole 30 mg qd. C(max) and AUC(0-tlast) of prasugrel's active metabolite, R-138727, and clopidogrel's inactive carboxylic acid metabolite, SR26334, were assessed. Inhibition of platelet aggregation (IPA) was measured by turbidimetric aggregometry 4 to 24 hours after each treatment. Lansoprazole (1) decreased R-138727 AUC(0-tlast) and C(max) by 13% and 29%, respectively, but did not affect IPA after the prasugrel dose, and (2) did not affect SR62334 exposure but tended to lower IPA after a clopidogrel dose. A retrospective tertile analysis showed in subjects with high IPA after a clopidogrel dose alone that lansoprazole decreased IPA, whereas IPA was unaffected in these same subjects after a prasugrel dose. The overall data suggest that a prasugrel dose adjustment is not likely warranted in an individual taking prasugrel with a proton pump inhibitor such as lansoprazole.

Pain relief model for a COX-2 inhibitor in patients with postoperative dental pain.

AIM: To develop a pain relief model for a cyclooxygenase (COX)-2 inhibitor, CS-706, that permits prediction of doses for acute pain relief in Japanese and Western populations. METHODS: A categorical response model was developed to describe the probability of pain relief (PR) over time for a Phase 2a study. Models were also developed to describe patient's use of rescue medication and onset of pain relief. RESULTS: The placebo response was described by a first-order increase in PR that achieved a stable response after 4 h. The effect of CS-706 on PR was described using an E(max) model; the plasma concentration of CS-706 producing 50% of the maximum response was estimated to be 87 ng ml(-1), the median peak plasma concentration achieved after a 50-mg oral dose. The probability of rescue medication (REMD) decreased over time and was a function of the last observed PR score. This probability was < 16% for patients with a PR score > or =2. The probability of experiencing meaningful PR was 98% in patients who did not require REMD and 47% in those who required REMD. For patients who did not require REMD, the median onset time of meaningful pain relief (TMPR) decreased with increasing doses. In patients who required REMD, there was a saturable decline in TMPR, with the greatest improvement occurring from placebo to 50-mg doses. CONCLUSIONS: The set of models developed permitted compilation of multiple dose-response curves for dose selection of CS-706 in Westerners and facilitated scaling of doses to a Japanese population.

Effect of atorvastatin on the pharmacokinetics and pharmacodynamics of prasugrel and clopidogrel in healthy subjects.

STUDY OBJECTIVE: To investigate the potential effect of atorvastatin 80 mg/day on the pharmacokinetics and pharmacodynamics of the thienopyridines prasugrel and clopidogrel. DESIGN: Open-label, randomized, crossover, two-arm, parallel-group study. SETTING: Single clinical research center in the United Kingdom. PARTICIPANTS: Sixty-nine healthy men aged 18-60 years. Intervention. Subjects received either a loading dose of prasugrel 60 mg followed by a maintenance dose of 10 mg/day or a loading dose of clopidogrel 300 mg followed by 75 mg/day. The drug was given as monotherapy for 10 days, and after a 6-day run-in period with atorvastatin 80 mg/day, the same dosage of atorvastatin was continued with the respective thienopyridine for 10 days. A 14-day washout period separated the treatment regimens. MEASUREMENTS AND MAIN RESULTS: Blood samples were collected before and at various time points after dosing on days 1 and 11 for determination of plasma concentrations of metabolites and for measurement of platelet aggregation induced by adenosine 5'-diphosphate 20 microM and vasodilator-stimulated phosphoprotein (VASP). Coadministration of atorvastatin did not alter exposure to active metabolites of prasugrel or clopidogrel after the loading dose and thus did not alter inhibition of platelet aggregation (IPA). During maintenance dosing, atorvastatin administration resulted in 17% and 28% increases in the area under the plasma concentration-time curve (AUC) values of prasugrel's and clopidogrel's active metabolites, respectively. These small changes in AUC did not result in a significant change in IPA response to prasugrel but did result in a significant increase in IPA during clopidogrel maintenance dosing at some, but not all, of the time points on day 11. Coadministration of atorvastatin with either prasugrel or clopidogrel had no effect on VASP phosphorylation relative to the thienopyridine alone after the loading dose. CONCLUSION: Coadministration of atorvastatin 80 mg/day with prasugrel or clopidogrel did not negatively affect the antiplatelet response to either drug after a loading dose or during maintenance dosing. The lack of a clinically meaningful effect of high-dose atorvastatin on the pharmacodynamic response to prasugrel after the loading or maintenance dose indicates that no dosage adjustment should be necessary in patients receiving these drugs concomitantly.