Iv Dose Research Articles

Preoperative tramadol combined with postoperative small-dose tramadol infusion after total abdominal hysterectomy: a double-blind, randomized, controlled trial

This double blind, randomized, controlled trial investigated whether a single preoperative intravenous (iv) dose of tramadol (100mg) given 30min before abdominal hysterectomy resulted in improved analgesic efficacy, reduced postoperative morphine patient-controlled analgesia (PCA) use and reduced side effects when combined with a postoperative small-dose tramadol infusion. Two-hundred twenty-four patients undergoing elective abdominal hysterectomy were randomly allocated to one of two groups: the tramadol group (n=113) received iv tramadol (100mg) 30min before surgery, and the control group (n=111) received an equivalent volume of normal saline. Upon awakening from general anesthesia, all patients received a loading dose of 0.5mg/kg of tramadol and a small-dose infusion of tramadol (0.1mg/kg/h) for 48h. In addition, all patients were connected to morphine PCA delivering a morphine bolus of 0.02mg/kg with a 6-min lock-out. Data on pain intensity at rest and during movement, morphine consumption, side-effects and overall patient satisfaction were recorded. A total of 189 patients completed the study. Preemptive tramadol was associated with superior analgesia at rest and with movement in the first 24h after surgery (p < 0.01), a longer interval to first morphine PCA request (p=0.019), and reduced morphine PCA use (p=0.017). The tramadol group had reduced nausea (p=0.015), dizziness (p=0.001) and drowsiness (p=0.0001), while other side-effects were similar. In conclusion, a single dose of iv tramadol (100mg) 30min prior to abdominal hysterectomy improves analgesia, and reduces morphine PCA requirements, nausea, dizziness and drowsiness when combined with a postoperative small-dose tramadol infusion and morphine PCA when compared to the same analgesic regimen that omitted the preemptive tramadol.

Physiologically Based Pharmacokinetics of Zearalenone

The objectives of this study were to (1) develop physiologically based pharmacokinetic (PBPK) models for zearalenone following intravenous (iv) and oral (po) dosing in rats and (2) predict concentrations in humans via interspecies scaling. The model for iv dosing consisted of vein, artery, lung, liver, spleen, kidneys, heart, testes, brain, muscle, adipose tissue, stomach, and small intestine. To describe the secondary peak phenomenon observed after po administration, the absorption model was constructed to reflect glucuronidation, biliary excretion, enterohepatic recirculation, and fast and slow absorption processes from the lumenal compartment. The developed models adequately described observed concentration–time data in rats after iv or po administration. Upon model validation in rats, steady-state zearalenone concentrations in blood and tissues were simulated for rats after once daily po exposures (0.1 mg/kg/d). The average steady-state blood zearalenone concentration predicted in rat was 0.014 ng/ml. Subsequently, a daily human po dose needed to achieve the same steady-state blood concentration found in rats (0.014 ng/ml) was determined to be 0.0312 mg/kg/d or 2.18 mg/70 kg/d. The steady-state zearalenone concentration–time profiles in blood and tissues were also simulated for human after multiple po administrations (dose 0.0312 mg/kg/d). The developed PBPK models adequately described the pharmacokinetics in rats and may be useful in predicting human blood and tissue concentrations for zearalenone under different po exposure conditions.

Disposition, Oral Bioavailability, and Tissue Distribution of Zearalenone in Rats at Various Dose Levels

This study was conducted to characterize the disposition, oral bioavailability, and tissue distribution of zearalenone in rats. The pharmacokinetics and tissue distribution of zearalenone were studied after intravenous (iv) or oral (po) administration at doses ranging from 1 to 8 mg/kg in intact and bile duct-cannulated rats. Serum, bile, and urine concentrations were determined by liquid chromatography and mass spectroscopy (LC/MS/MS) and tissue concentrations by high-performance liquid chromatography (HPLC)/fluorescence detection assays. Noncompartmental methods were used for pharmacokinetic analysis. Average Cls (range 5.0–6.6 L/h/kg) and Vdss (range 2–4.7 L/kg) remained unaltered over an iv dose range from 1 to 8 mg/kg, and area under the concentration–time curve (AUC) and initial peak concentrations increased linearly with dose. Minimal quantities of zearalenone were excreted unchanged in urine (fe,urine 0.5 ± 0.2%) and bile (fe,bile 0.91 ± 0.64%). After po administration of 8 mg/kg, zearalenone was rapidly absorbed and serum concentration–time profiles showed a distinct second peak. The absolute oral bioavailability was low (2.7%). Comparing bile duct-cannulated to intact rats at a dose of 8 mg/kg, the impact of biliary excretion on overall pharmacokinetics was more pronounced after po than after iv administration. Upon iv infusion to steady state, the highest zearalenone concentration was found in small intestine, followed by kidneys, liver, adipose tissue, and lung. Zearalenone concentrations in stomach, heart, brain, spleen, muscle, and testes were lower than those found in serum. The pharmacokinetics and tissue distribution data from this study may be useful to develop physiologically based pharmacokinetic (PBPK) models for zearalenone and subsequently to predict the pharmacokinetics and toxicity in humans.

Nab‐Paclitaxel: a bright new SPARC in taxane therapy of cancer

Nab‐Paclitaxel: a bright new SPARC in taxane therapy of cancer

Attualità e controversie nella terapia delle malattie infiammatorie croniche intestinali

The treatment of Inflammatory bowel disease comes from many years of esperience, clinical trials and mistakes. In patients with active Crohn disease steroids are considerated the first choice, but recently, the introduction of anti-TNF alfa agents (infliximab and adalimumab) has changed the protocols. Anti-TNF are also used for closing fistula after surgical curettage. An efficently preventive treatment of Crohn disease still has not been found but hight dose of oral salicylates, azatioprine or 6-MP and antibiotics might be useful. In severe attacks of ulcerative colitis, high dose iv treatment of steroids are required for a few days. Later on, a further treatment with anti-TNF might delay the need of surgery. In patients with mild to moderate attacks of ulcerative colitis, topical treatment is preferred, it consists of enemas, suppositories or foams containing 5-aminosalycilic acid, traditional steroids, topical active steroids. Topical treatment can be associated with oral steroids or oral salicylates. Oral salicylates or azatioprine are used for prevention of relaps.

Primordial Follicles in the Mouse Ovary Are Not Renewed after Depletion with Ovotoxins or Irradiation.

The notion of a fixed, non-renewable pool of oocytes in the ovary around birth was questioned after reports of germline stem cells giving rise to new oocytes in the adult ovary. Our aims were to test the hypothesis that in the C57BL/6 mouse ovary, the primordial follicle pool can be restored de novo after treatment with ovotoxins or γ-irradiation, which substantially reduce the size of the primordial pool. Exp1 Mice (6 wk old) received doxorubicin (DXR;5mg/kg/100 μL saline) via tail iv and ovaries were collected at 1, 2 and 7 days later (7/group). Control ovaries (6 wk; 7/group; vehicle) were collected at 6 and 7 wk. Exp 2 Mice (6 wk old) received DXR (5mg/kg/100 μL saline) via tail iv and repeat doses at 7 and 8 wk, and ovaries collected at 10 wk. Control ovaries (6 wk; n=7; vehicle) were collected at 10 wk. Exp3 Mice (25 day old) received Trichostatin A (TSA;10mg/kg/100 μL DMSO sc). Ovaries were collected at 1 and 7 days (7-8/group). Control ovaries (day 25; 7/group; vehicle) were collected at days 1 and 7. Exp 4 Mice (5 days old) were whole-body gamma-irradiated with either 0.45Gy (n=6) or 4.5Gy (n=6) or untreated (controls; n=6) and ovaries collected at 10 days. Primordial and primary follicles per ovary (mean ± sem) in Exps 1-3 were estimated using the fractionator/optical disector technique. In randomly selected ovaries from Exp 4, follicles with an oocyte nucleus were counted in 3 selected 5μm sections per ovary and the area (μm2) of the sections measured with image analysis software. Representative follicle numbers per ovary and per group (mean ± sem) were expressed per 104 μm2 ovarian tissue area. At 1 and 2 days after DXR treatment, mean primordial follicle numbers per ovary declined significantly (P < 0.05) to 65% from their mean number in 6 wk control ovaries and declined further to 51% (P< 0.01) at 7 days after DXR treatment. Over the same treatment period mean primary follicle numbers per ovary were unchanged (P=0.89) in comparison to controls. Following multiple DXR treatments beginning at 6 wk, mean primordial follicle numbers per ovary at 10 wk had declined significantly (P< 0.001) to 28% in comparison to the age-matched controls but primary follicle numbers per ovary were not significantly different (P=0.91) compared with age-matched controls. Between 1 and 7 days after TSA treatment, mean primordial follicle numbers per ovary declined significantly (P < 0.01) to 51% and 61% compared to the mean number in day 25 control ovaries, whereas mean primary follicle numbers per ovary after TSA treatment were not significantly different (P =0.27) in comparison to control. Estimates of primordial and primary follicle numbers in 10 day ovaries after exposure to 0.45Gy or 4.5Gy gamma-irradiation on day 5 showed their respective total or near complete elimination (P< 0.001). There was no evidence in any of the treatments of a significant restoration of primordial numbers in the time frames examined. The results suggest that if primordial follicle numbers are experimentally reduced, there is no compensatory mechanism for full or partial renewal of the follicle pool. Supported by NH&MRC of Australia (#441101 & 241000). (poster)

Cyclooxygenase-1 or -2—which one mediates lipopolysaccharide-induced hypothermia?

Systemic inflammation is associated with either fever or hypothermia. Fever, a response to mild systemic inflammation, is mediated by cyclooxygenase (COX)-2 and not by COX-1. However, it is still disputed whether COX-2, COX-1, neither, or both mediate(s) responses to severe systemic inflammation, and, in particular, the hypothermic response. We compared the effects of SC-236 (COX-2 inhibitor) and SC-560 (COX-1 inhibitor) on the deep body temperature (T(b)) of rats injected with a lower (10 microg/kg i.v.) or higher (1,000 microg/kg i.v.) dose of LPS at different ambient temperatures (T(a)s). At a neutral T(a) (30 degrees C), the rats responded to LPS with a polyphasic fever (lower dose) or a brief hypothermia followed by fever (higher dose). SC-236 (2.5 mg/kg i.v.) blocked the fever induced by either LPS dose, whereas SC-560 (5 mg/kg i.v.) altered neither the febrile response to the lower LPS dose nor the fever component of the response to the higher dose. However, SC-560 blocked the initial hypothermia caused by the higher LPS dose. At a subneutral T(a) (22 degrees C), the rats responded to LPS with early (70-90 min, nadir) dose-dependent hypothermia. The hypothermic response to either dose was enhanced by SC-236 but blocked by SC-560. The hypothermic response to the higher LPS dose was associated with a fall in arterial blood pressure. This hypotensive response was attenuated by either SC-236 or SC-560. At the onset of LPS-induced hypothermia and hypotension, the functional activity of the COX-1 pathway (COX-1-mediated PGE(2) synthesis ex vivo) increased in the spleen but not liver, lung, kidney, or brain. The expression of splenic COX-1 was unaffected by LPS. We conclude that COX-1, but not COX-2, mediates LPS hypothermia, and that both COX isoforms are required for LPS hypotension.

Phase I study of pemetrexed in recurrent/metastatic head and neck squamous cell cancer (HNSCC) and to assess the need for steroid premedication

e17009 Background: Pemetrexed is a novel antimetabolite that inhibits both purine and pyrimidine biosynthesis. Because its mechanism of action is similar to that of both methotrexate and 5-FU, it may also have activity in recurrent/metastatic HNSCC, a disease with limited treatment options and very poor median survival. Pemetrexed is traditionally prescribed with steroids due to skin toxicities observed in early studies; however vitamin supplementation (B12 and folic acid) was not standard at the time of those studies. No study to date has evaluated the optimal use of steroids with pemetrexed in the era of vitamin supplementation. Methods: All patients had metastatic or recurrent HNSCC, were treated with at least one prior chemotherapy regimen, and had ECOG PS of 0–2. The first cohort of patients received pemetrexed 500 mg/m2 every 3 weeks and the next receiving 600 mg/m2 based on a predefined standard dose escalation design. Within each dose level, patients were randomized to one of 3 premedication regimens: no dexamethasone, 20 mg IV on day 1, or standard 4 mg orally bid for 3 days. All patients received vitamin supplementation. The primary endpoint of the study was to determine the maximum tolerated dose of pemetrexed based on steroid premedication. Results: From October 2005 to March 2008, 36 patients were enrolled and 31 were available for evaluation. Median age was 57 years (range 42–82). 51.5% of patients had more than one prior chemotherapy regimens, 81.8% of patients had prior radiation therapy, and 48.5% of patients had prior surgery. Incidence of rash and combined skin toxicities were: 1/11 (9%) and 3/11 (27%) of patients without steroids, 1/11 (9%) and 3/11 (27%) with single IV dose, and 4/9 (44%) and 5/9 (55%) with oral steroids. No treatment-related grade 3 toxicities were observed. One patient initially received no steroid and required dose reduction and addition of steroid due to grade 2 rash. A partial response was observed in one patient (3.2%), and stable disease in 8 patients (25.8%) for a disease control rate of 29%. Conclusions: This is the first study to report the role of steroids as a premedication for pemetrexed. Our data suggests that no steroid premedication is needed with pemetrexed and vitamin supplementation. [Table: see text]

A novel neurotrophic therapeutic strategy for experimental stroke

Human chorionic gonadotropin (hCG) promotes proliferation of endogenous neural stem cells, and erythropoietin (EPO) promotes differentiation of these cells into neural stem cells. The current study examined effects of sequential administration of these two compounds, initiated 24 h after stroke. At that time, rats were randomized into four treatment groups: hCG+EPO (3 IM doses hCG over 5 days, followed by 3 IV doses EPO over 3 days), hCG+Saline using the same schedule, Saline+EPO using the same schedule, or neither drug (Saline+Saline). The primary endpoint was the composite neurological score, measured 11 times, from 1 h until 12 weeks post-insult. The neurological score was different across treatment groups ( p < 0.03). Pairwise testing of groups found that the hCG+EPO group had significantly better behavior at 6/10 post-stroke time points as compared to Saline+Saline. The differences observed when comparing the two-drug group with placebo were less apparent when comparing either of the one-drug groups with placebo. The two one-drug treatment arms did not significantly differ at any time point. Treatment with hCG+EPO significantly reduced total lesion volume by 82–89% compared to the other three treatment groups. The current therapeutic strategy improved behavioral outcome and reduced lesion volume with a time window of 24 h after the onset of stroke. The results from these experiments provide new insight into the effects of these two growth factors on stroke in rats, and could suggest a potential for translation into human stroke studies.

Combination of trastuzumab, oxaliplatin, and docetaxel as first-line treatment in HER2-positive metastatic breast cancer patients: First-step results of a phase II trial (HOT trial)

1132 Background: The addiction of trastuzumab to standard chemotherapy has improved the outcome of HER-2-positive metastatic breast cancer (MBC) pts. Oxaliplatin and docetaxxel are among the most active agents in MBC pts pretreated with anthracyclines. In vitro studies showed synergistic effect of the combination. We investigated the feasibility and the safety of the 3-drug combination given as first line chemotherapy (CT) in HER-2-positive MBC. Methods: HER-2-positive MBC pts were prospectively enrolled to receive a first-line treatment consisting of trastuzumab 8 mg/kg loading dose iv (followed by 6 mg/kg) on day 1, docetaxel 75 mg/sqm iv on day 1, and oxaliplatin 70 mg/sqm on day 2 every 21 days. All pts received peg-filgrastim 6 mg on day 3 to prevent bone marrow toxicity. Pts received up to 9 cycles of CT. Primary end points were overall response rate (ORR) (according to RECIST criteria), clinical benefit (CB), and tolerability. Cardiac function was evaluated by echocardiography at baseline, each 3 courses and at the end of treatment. Results: To date, 13 pts have been enrolled (median age 59 yrs [range 34–70]; ECOG PS 0) representing the first-step accrual according to Minimax design. Ten pts had previously received anthracyclines as adjuvant treatment and 11 pts presented with visceral metastasis. All pts received at least 6 cycles of treatment with 7 pts continuing up to 9 cycles. Response and toxicity data are available for all pts. Two pts experienced CR, 7 pts PR, and 4 pts showed SD (lasting more than 6 months in 3 cases) with an ORR of 70% and a CB of 100%. No pts progressed during treatment. No grade 4 toxicity was observed. Most common grade 3 toxicities were diarrhea (18%), nausea/vomiting (22%), mucositis (11%). In particular, 2 episodes of febrile neutropenia were reported and no grade 4 haematologycal toxicity was observed. No significative reduction of LVEF were reported. Conclusions: The combination of trastuzumab, oxaliplatin, and docetaxel (HOT combination) showed promising activity and was well tolerated as first-line treatment in pts with HER-2-positive MBC. Peg-filgrastim profilaxis improved safety profile. No significant financial relationships to disclose.

Pharmacokinetics and metabolism of the putative cancer chemopreventive agent cyanidin-3-glucoside in mice

Cyanidin-3-glucoside (C3G), an anthocyanin component of fruits and berries, possesses cancer chemopreventive properties in mouse models of carcinogenesis. Its pharmacokinetics and metabolism in mice have hitherto not been studied. C57BL6J mice received C3G by either gavage at 500 mg/kg or tail vein injection at 1 mg/kg. Blood, urine, bile and heart, lung, kidney, liver, prostate, brain and gastrointestinal (gi) mucosal tissues were obtained up to 2 h after administration. Levels of C3G and its anthocyanin metabolites were determined by HPLC with visible detection. Metabolites were identified by LC/MS/MS. After oral administration peak concentrations of anthocyanins occurred within 30 min after administration. Levels were highest in the urine and gi mucosa. In the gi mucosa and liver the predominant flavonoid species after oral administration was C3G, whilst after iv dosing the majority of anthocyanins was C3G metabolites. After oral or iv administration, C3G half-lives in the different biofluids and tissues ranged from 0.7 to 1.8 h and 0.3 to 0.7 h, respectively. Systemic bioavailabilities for parent C3G and total anthocyanins were 1.7 and 3.3%, respectively. The major metabolites of C3G were products of methylation and glucuronidation. Cyanidin was a minor metabolite in the gut. C3G and its metabolites were recovered from murine tissues which may be targets for cancer chemopreventive intervention. Anthocyanin levels achieved in the gi mucosa, prostate and the kidneys were of an order of magnitude consistent with pharmacological activity.

Development of PBPK model of molinate and molinate sulfoxide in rats and humans

Molinate has been widely used as a pre-emergent herbicide in the rice fields of California’s Central Valley. In rat studies, the metabolite molinate sulfoxide is suspected of causing testicular toxicity after exposure to molinate. The sulfoxide is generated in the liver and can circulate in the blood, eventually reaching the testis. Man qualitatively produces the same molinate metabolites as the rat. To extrapolate the reproductive risk to man, the present study outlines the development of a preliminary PBPK (physiologically-based pharmacokinetic) model, validation in the rat and extrapolation to man. The preliminary seven-compartment PBPK model for molinate was constructed for the adult, male Sprague–Dawley rat that employed both flow-limited (blood, kidney, liver, rapid-perfused tissues and slowly perfused tissues) and diffusion-limited (fat) rate equations. The systemic circulation connects the various compartments. The simulations predict the molinate blood concentrations of the rat blood and testes compartment favorably with the profiles obtained from 10 and 100 mg/kg po or 1.5 and 15 mg/kg iv doses. Human physiological parameters were substituted into the oral dosed model and the simulations closely predicted the molinate blood concentration obtained from 5.06 mg oral dose. A sensitivity analysis determined for an oral dose that peak blood molinate concentrations were most responsive to the blood flows to kidney and fat compartments while testicular molinate sulfoxide concentrations depended on molinate sulfoxide partition coefficients for the testes compartment and the K m for glutathione conjugation of molinate sulfoxide in the liver compartment.

Hypnotic interaction between midazolam and different doses of propofol

Objective To evaluate the hypnotic interaction between midazolam and different doses of propofol. Methods One hundred and twenty ASA Ⅰor Ⅱpatients (43 male, 77 female) aged 18-60 yr weighing 40-80 kg undergoing elective surgery were randomly divided into 4 groups (n=30 each):group Ⅰmidazolam (M); group Ⅱ propofol (P) and group Ⅲ, Ⅳ midazolam + propofol (MP1, MP2). Six doses of midazolam (0.04, 0.06, 0.08, 0.1, 0.12, 0.15 mg/kg) and propofol (0.8, 1.0, 1.2, 1.5, 1.8 mg/kg) were given iv in group M and P respectively. OAA/S scale was used to assess the level of sedation (5=alert, 1=only responds to squeezing deltoid muscle). The hypnotic end point was defined as an OAA/S score ≤2. The level of sedation was assessed at 3 min after midazolam administration in group M and at 1 min after propofol administration in group P, MP1and MP2 . ED50 (95 % confidence intervals,95 % CI) of midazolam and propofol were determined by probit analysis in group M and P. Isobolographic analysis was used to analyze the interaction between the two drugs. The ratio of ED50 of midazolam to ED50 of propofol was 1:13 in group MP1 and 1:10 in group MP2 . Results The ED50 (95 % CI) of midazolam for hypnosis was 0.088 (0.066-0.110), 0.031 (0.026-0.036) and 0.045 (0.040-0.049) mg/kg respectively in group M, MP1 and MP2. The ED50 (95% CI) of propofol for hypnosis was 1.142(0.933-1.350), 0.421 (0.343-0.480), 0.450 (0.399-0.491) mg/kg respectively in group P, MP1,MP2. Isobolographie analysis confirmed that midazolam and propofol interacted synergistically at the ratio of 1: 13in group MP1 and additively at the ratio of 1:10 in group MP2 . Conclusion Midazolam and propofol interact synergistically at the ratio of 1:13 but additively at the ratio of 1:10. Key words: Propofol; Midazolam; Dose-response relationship, drug; Drug interactions; Hypnosis, anesthetic

Pharmacokinetic parameters of artesunate and dihydroartemisinin in rats infected with Fasciola hepatica

The pharmacokinetic (PK) parameters of artesunate, recently discovered to possess promising trematocidal activity, and its main metabolite dihydroartemisinin (DHA) were determined in rats infected with hepatic and biliary stages of Fasciola hepatica and compared with uninfected rats after single intragastric and intravenous (iv) doses. Rats infected with F. hepatica for 25 and 83 days and uninfected rats were cannulated in the right jugular vein and blood samples were withdrawn at selected timepoints following 10 mg/kg of iv and a single 100 mg/kg oral dose of artesunate. Plasma was analysed for artesunate and DHA by liquid chromatography coupled to tandem mass spectrometry. Rats harbouring juvenile and adult F. hepatica infections revealed considerable changes in PK parameters of artesunate and DHA. Following oral administration, maximum plasma concentrations (C(max)) of artesunate and DHA were 1.8-2.3-fold higher in infected rats [artesunate: 1334 +/- 1404 ng/mL (no infection) versus 2454 +/- 1494 ng/mL (acute infection) and 2768 +/- 538 ng/mL (chronic infection); DHA: 3802 +/- 2149 ng/mL (no infection) versus 6507 +/- 3283 ng/mL (acute infection) and 9093 +/- 884 ng/mL (chronic infection)]. The AUCs of artesunate and DHA were 2.1-4.4-fold greater in infected rats. An opposite trend was observed after iv injection. C(max) and AUC of artesunate and DHA following iv dosing were 5784 +/- 3718 and 140 938 +/- 128 783 ng.min/mL and 3849 +/- 3060 and 86 107 +/- 41 863 ng.min/mL, respectively, in uninfected rats versus 2623 +/- 1554 and 21 617 +/- 12 230 ng.min/mL and 2835 +/- 980 and 64 290 +/- 29 057 ng.min/mL, respectively, in rats harbouring a chronic infection. The elimination half-lives (t(1/2)) of artesunate and DHA were considerably altered in infected rats following oral and iv administration of artesunate. F. hepatica infections strongly influence the disposition kinetics of artesunate and its metabolite in rats. The clinical implications of this finding need to be carefully studied.

Differences in tissue drug concentrations following intravenous versus intraperitoneal treatment with amphotericin B deoxycholate or liposomal amphotericin B

Amphotericin B formulations were compared in preclinical models by using intraperitoneal (ip) and intravenous (iv) delivery of amphotericin B deoxycholate (DAMB) or liposomal amphotericin B. We examined the effects on drug tissue penetration and retention resulting from different routes of drug administration. Mice were treated with equivalent total doses of AmBisome (AmBi) or DAMB (i.e.,15 mg/kg) given ip (3 mg/kg/day for 5 days) or iv (3 mg/kg/day AmBi for 5 days or 1 mg/kg/day DAMB for 15 days), with tissues collected 24 h post-treatment. For drug retention studies, mice were given iv or ip total doses of 30 mg/kg AmBi (10 mg/kg/day 3 x /week) or 60 mg/kg AmBi (20 mg/kg/day 3 x /week) with tissue collection 24 h or 7 days post-treatment. Blood samples were collected at 0.5 h, 2 h, 8 h, 12 h and 24 h after ip or iv drug dosing. A Paecilomyces variottii bioassay was used to determine drug concentrations. AmBi and DAMB were detected in the kidneys following iv, but not ip dosing. Significantly more DAMB than AmBi was detected in the lungs with ip dosing (P = 0.008), and more AmBi than DAMB (P = 0.056) was present with iv dosing. Unlike the lungs, the spleen and liver retained the AmBi for up to one week post-treatment regardless of the route of drug administration. Thus, there are significant differences in AmBi and DAMB tissue distribution depending upon the drug route and these differences could effect how the drugs perform in fungal infection models.

Comparing models for perfluorooctanoic acid pharmacokinetics using Bayesian analysis

Selecting the appropriate pharmacokinetic (PK) model given the available data is investigated for perfluorooctanoic acid (PFOA), which has been widely analyzed with an empirical, one-compartment model. This research examined the results of experiments [Kemper R. A., DuPont Haskell Laboratories, USEPA Administrative Record AR-226.1499 (2003)] that administered single oral or iv doses of PFOA to adult male and female rats. PFOA concentration was observed over time; in plasma for some animals and in fecal and urinary excretion for others. There were four rats per dose group, for a total of 36 males and 36 females. Assuming that the PK parameters for each individual within a gender were drawn from the same, biologically varying population, plasma and excretion data were jointly analyzed using a hierarchical framework to separate uncertainty due to measurement error from actual biological variability. Bayesian analysis using Markov Chain Monte Carlo (MCMC) provides tools to perform such an analysis as well as quantitative diagnostics to evaluate and discriminate between models. Starting from a one-compartment PK model with separate clearances to urine and feces, the model was incrementally expanded using Bayesian measures to assess if the expansion was supported by the data. PFOA excretion is sexually dimorphic in rats; male rats have bi-phasic elimination that is roughly 40 times slower than that of the females, which appear to have a single elimination phase. The male and female data were analyzed separately, keeping only the parameters describing the measurement process in common. For male rats, including excretion data initially decreased certainty in the one-compartment parameter estimates compared to an analysis using plasma data only. Allowing a third, unspecified clearance improved agreement and increased certainty when all the data was used, however a significant amount of eliminated PFOA was estimated to be missing from the excretion data. Adding an additional PK compartment reduced the unaccounted-for elimination to amounts comparable to the cage wash. For both sexes, an MCMC estimate of the appropriateness of a model for a given data type, the Deviance Information Criterion, indicated that this two-compartment model was better suited to describing PFOA PK. The median estimate was 142.1 +/- 37.6 ml/kg for the volume of the primary compartment and 1.24 +/- 1.1 ml/kg/h for the clearances of male rats and 166.4 +/- 46.8 ml/kg and 30.3 +/- 13.2 ml/kg/h, respectively for female rats. The estimates for the second compartment differed greatly with gender-volume 311.8 +/- 453.9 ml/kg with clearance 3.2 +/- 6.2 for males and 1400 +/- 2507.5 ml/kg and 4.3 +/- 2.2 ml/kg/h for females. The median estimated clearance was 12 +/- 6% to feces and 85 +/- 7% to urine for male rats and 8 +/- 6% and 77 +/- 9% for female rats. We conclude that the available data may support more models for PFOA PK beyond two-compartments and that the methods employed here will be generally useful for more complicated, including PBPK, models.

Optimizing dosing frequencies for bisphosphonates in the management of postmenopausal osteoporosis: patient considerations

Postmenopausal osteoporosis is common and underrecognized among elderly women. Osteoporotic fractures cause disability and disfigurement and threaten patients' mobility, independence, and survival. Care for incident fractures in this age group must go beyond orthopedic repair, to assessment and treatment of the underlying bone fragility. Fracture risk can be reduced by vitamin D and calcium supplementation along with antiresorptive drug treatment. First-line osteoporosis pharmacotherapy employs nitrogen-containing bisphosphonates. The inconvenience of daily oral treatment has motivated development of weekly, monthly, and intermittent oral regimens, as well as quarterly and yearly intravenous (i.v.) regimens. Ibandronate is the first bisphosphonate to have shown direct anti-fracture efficacy with a non-daily regimen; it was approved for once-monthly oral dosing in 2005 and for quarterly i.v. dosing in 2006. Intermittent oral risedronate and yearly i.v. zoledronic acid were approved in 2007. Newly available regimens with extended dosing intervals reduce the inconvenience of bisphosphonate therapy and provide patients with a range of options from which to select a maximally sustainable course of treatment. This review discusses the development, efficacy, safety, and tolerability of extended-interval bisphosphonate regimens and examines their potential to improve patient acceptance and long-term success of osteoporosis treatment.

Sym001, the First Recombinant Polyclonal Rhesus-D Specific Antibody Product, Was Safe and Well-Tolerated in a Placebo-Controlled Randomized Phase I Trial.

Sym001 is the first compound in a new class of biopharmaceuticals in clinical development for the treatment of Immune Thrombocytopenic Purpura (ITP), and the prevention of hemolytic disease of the newborn by anti-D prophylaxis (ADP). Sym001 is a recombinant polyclonal antibody product consisting of 25 different anti-Rhesus D specific (RhD) antibodies. The primary objective of this clinical study was to assess the safety of Sym001 following a single intravenous (iv) dose in RhD+ and RhD− healthy male volunteers. Secondary objectives were to assess the potential immunogenicity and pharmacokinetic (PK) profile of Sym001. Fifty-nine RhD+ subjects and 18 RhD− subjects were randomized to receive up to 12.5 μg/kg or 75 μg/kg, respectively, in seven dose cohorts as shown below:Number of SubjectsCohortDose (μg/kg)RhD+ Sym001RhD+ PlaceboRhD− Sym001RhD− Placebo10.25520021.0520034.07272412.57272525720065072007757200Treatment with Sym001 was well tolerated and there were no serious adverse events (SAEs), no AEs of severe intensity and no AEs that resulted in discontinuation of the study in either the RhD+ or RhD− population. The frequencies of treatment-emergent AEs (TEAE), i.e. AEs occurring after drug administration, were similar among Sym001 and placebo treated subjects and there was no dose-dependent pattern of TEAEs. No significant decrease in mean hemoglobin level compared to baseline was observed at any dose level during the study, and no decrease in hemoglobin > 2 g/dL in any subject was seen. No other laboratory findings were suggestive of clinically significant hemolysis. In addition, no clinically significant changes in vital signs or electrocardiograms (ECGs) were observed, and there were no significant changes in clinical chemistry variables that did translate into SAEs or were assessed as being related to study medication. No immunogenicity to Sym001 was detected and analysis of PK is in progress. In conclusion, Sym001 was found to be safe and well-tolerated in healthy volunteers in doses up to 75 μg/ kg. Sym001 is now being evaluated in a red blood cell (RBC) challenge trial for the ADP indication and in a Phase II trial for treatment of patients with ITP.

Rapid Mobilization of Long Term Repopulating Hematopoietic Stem Cells (HSC) with AMD15057, a Small Molecule Inhibitor of VLA4; Synergism with AMD3100 and G-CSF

Background: Hematopoietic stem cells (HSC) interact with stromal cells, osteoblasts and matrix proteins in the hematopoietic niche. This interaction plays an important role in HSC trafficking, proliferation and differentiation. Significant data support the roles of both the SDF-1/CXCR4 and the VCAM1-VLA-4 axes in stem cell homing and mobilization. Two recent reports have shown that Natalizumab, an anti-VLA-4 monoclonal antibody used in the treatment of Multiple Sclerosis, induces mobilization of CD34+ HSC over several days. In the present study we tested the specificity and efficacy of a novel VLA-4 small molecule inhibitor, AMD15057, in murine preclinical studies of normal HSC mobilization.Methods: Fibronectin adhesion assays were performed with Jurkat cells to test the specificity of AMD15057. Ninety-six well plates were coated with fibronectin or BSA and the inhibition of Jurkat cell (VLA-4 +) adhesion by AMD15057 was determined in the presence or absence of PMA activation. To evaluate the mobilization of HSC progenitors, 8 week old 129/B6 F1 mice (n=6 per group, 3 experiments) were left untreated (unmobilized) or treated with AMD15057 (0.1,1,3 mg/kg iv or 3,5,7 mg/ kg sc), AMD3100 (1,3 mg/kg iv or 1,3,5 mg/kg sc), G-CSF (250 mg/kg/d × 5 d) or combinations. Total WBC and CFU-GM were determined at different time points for each mobilization regimen. For long-term competitive repopulation cell assays (LTRC), PBMCs from 3 Ly5.2+ unmobilized or mobilized mice (700uL PB each) were pooled, mixed with 5×105 Ly5.1+ BM mononuclear cells (MNC) (3:1 ratio) and injected into lethally irradiated Ly5.1+/Ly5.2+ compound heterozygote recipient mice. Chimerism was evaluated monthly for 6 months by flow cytometry. Secondary transplants to evaluate long term repopulation activity was performed by injecting lethally irradiated heterozygotes with 106 BM pooled MNC from the primary recipients.Results: The adhesion of untreated and PMA treated Jurkat cells to fibronectin coated wells was decreased by 62% (3.2 SD) and 69% (3.4 SD) (p<0.001) respectively, upon the addition of 1ug/ml AMD15057 compared to vehicle control. In vivo, a single iv or sc injection of AMD15057 resulted in maximum mobilization of CFU-GM within 0.5–0.75 hr. This effect was dose dependent for both sc and iv administrations. Maximum and comparable peak mobilization (13-fold iv; 9-fold sc, pNS) and kinetics of murine HSC mobilization was seen in mice receiving 1mg/kg iv and 5mg/kg sc AMD15057. In contrast, iv dosing of a small molecule inhibitor of CXCR4, AMD3100 (3mg/kg optimal dose) resulted in more rapid peak mobilization (10-fold) in <1hr compared to 3hr peak mobilization (20-fold) after sc dosing (5mg/kg optimal dose). Combination of AMD15057 (1mg/kg iv) with AMD3100 (5mg/kg sc) resulted in synergistic mobilization of CFU-GM (60-fold) when compared to each agent alone (p<0.01). In addition, when AMD3100 and AMD15057 were administered to mice after 5 days of mobilization with G-CSF (17-fold), a dramatic, rapid and reversible mobilization of CFU-GM was observed (200-fold) which was significantly higher than G-CSF+AMD3100 (90-fold) and G-CSF+AMD15057 (90-fold). LTRC assays confirmed that both AMD3100 and AMD15057 induced the rapid mobilization of short and long term repopulating cells and that this effect was synergistic when both agents were co-administered and exceed the LTRC seen after G-CSF mobilization. Secondary transplants confirmed the long term repopulating capacity of HSC mobilized with AMD15057.Conclusions: The VCAM1/VLA-4 axis is involved in HSC trafficking. AMD15057 is effective in blocking the interaction between VLA4 and its ligand fibronectin. AMD15057 induces rapid and reversible mobilization of normal progenitors and HSC which have the long term repopulating capacity. Finally, a dramatic synergistic effect was observed when AMD15057 was combined with AMD3100, G-CSF and the combination. The results provide a plausible foundation for replacing G-CSF with small molecule inhibitors of CXCR4 and VLA-4 for rapid and reversible HSC mobilization in humans.

The discovery of AZD5597, a potent imidazole pyrimidine amide CDK inhibitor suitable for intravenous dosing

The development of a novel series of imidazole pyrimidine amides as cyclin-dependent kinase (CDK) inhibitors is described. Optimisation of inhibitory potency against multiple CDK’s (1, 2 and 9) resulted in imidazole pyrimidine amides with potent in vitro anti-proliferative effects against a range of cancer cell lines. Excellent physiochemical properties and large margins against inhibition of CYP isoforms and the hERG ion channel were achieved by modification of lipophilicity and amine basicity. A candidate with disease model activity in human cancer cell line xenografts and with suitable physiochemical and pharmacokinetic profiles for intravenous (iv) dosing was selected for further development as AZD5597.