Disposition of flurbiprofen in man: influence of stereochemistry and age

1. The stereoselective metabolism and pharmacokinetics of the enantiomers of flurbiprofen were investigated following the oral administration of the racemic drug (100 mg) to four young and four elderly healthy volunteers (two males and two females per group). 2. The stereochemical composition of the drug and the 4'-hydroxy- metabolite in serum and the drug, 4'-hydroxy- and 3'-hydroxy-4'-methoxy- metabolites, both free and conjugated, in urine were determined by a direct chromatographic method of enantiomeric analysis. 3. Modest enantioselectivity in clearance (CL S/R: young, 0.86; elderly, 0.88) was largely responsible for the apparent elimination half-life of (S)-flurbiprofen being significantly greater (p<0.01) than that of the R-enantiomer in both age groups (young, S: 5.2 +/- 0.7 versus R: 4.5 +/- 0.6 h; elderly, S: 9.6 +/- 1.2 versus R: 7.1 +/- 1.0 h). The serum concentrations of 4'-hydroxyflurbiprofen were five- to 20-fold lower than those of the corresponding drug enantiomers, stereoselective disposition being evident in the significantly greater (p<0.05) apparent half-lives of the S- compared with the R-enantiomer in both groups (young, S: 10.6 +/- 2.4 versus R: 6.7 +/- 1.1 h; elderly, S: 13.7 +/- 1.7 versus R: 10.2 +/- 1.2 h). 4. Some 60 and 72% of the dose was excreted in 24-h urine in elderly and young volunteers, respectively, a significantly greater (p<0.05) proportion of which was of the R-configuration in both age groups (S/R: young, 0.87; elderly, 0.81). The major urinary excretion products were flurbiprofen and 4'-hydroxyflurbiprofen, and their acyl-conjugates in both groups. 5. Age-associated differences in the pharmacokinetics of flurbiprofen occurred in a non-stereoselective manner and were primarily as a consequence of a significant approximately 40% decrease (p<0.01) in clearance of both enantiomers in the elderly due to reduced metabolic activity. Consequently, the elderly had greater exposure to both enantiomers, as reflected by the AUCs(0-inf) being significantly higher (p<0.05), by 60%, in this age group compared with the young. 6. The findings suggest that age-related alterations in the disposition of flurbiprofen could have significant implications for the use of the drug in the elderly.     

Effects of calcitriol on bone mineral density in patients treated with esomeprazole

Context: Proton pump inhibitor (PPI) increases the risk of decrease in bone mineral density (BMD). However, whether calcitrol improves this situation is unknown.

Objective: The current study investigates the effects of calcitriol on BMD in patients with esomeprazole therapy.

Materials and methods: Three hundred and eighty-six participants with gastrointestinal ulcerations were enrolled and randomly assigned into controlled and supplemented groups. Participants in the controlled group were prescribed esomeprazole (20?mg/qd), while the supplemented group was prescribed esomeprazole (20?mg/qd) and calcitriol (2.5?μg/qd). BMD, serum levels of calcium, carboxy-terminal collagen crosslinks (CTX), and alkaline-phosphatase (ALP) were assessed.

Results: (1) No significant between-group difference of age, gender, smoking, previous glucocorticoid use and hemoglobin level was found; (2) after 10.6?±?0.8?d of PPI therapy, BMD T score in the controlled group was slightly increased compared with initial (?1.25?±?0.08 versus ?1.28?±?0.06, p?=?0.084), while there was no change in the supplemented group (?1.25?±?0.05 versus ?1.26?±?0.03, p?=?0.308); (3) during study termination, calcium level in the supplemented group was slightly higher than the controlled group (2.05?±?0.03?mmol/L versus 2.01?±?0.05?mmol/L, p?=?0.073), while no significant differences of CTX (366.57?±?43.71?pg/mL versus 373.15?±?50.23?pg/mL, p?=?0.036) and ALP were found among these two groups (50.47?±?9.32?U/L versus 52.23?±?10.45?U/L, p?=?0.075).

Conclusion: Patients with gastrointestinal ulcerations with esomeprazole therapy, calcitriol supplement showed no efficacy on BMD changes.     

Identification of cytochrome P450 enzymes involved in the metabolism of 4′-methoxy-α-pyrrolidinopropiophenone (MOPPP), a designer drug,in human liver microsomes

1. The metabolism of 4′-methoxy-α-pyrrolidinopropiophenone (MOPPP), a novel designer drug, to its demethylated major metabolite 4′-hydroxy-pyrrolidinopropio-phenone (HO-PPP) was studied in pooled human liver microsomes (HLM) and in cDNA-expressed human hepatic cytochrome P450 (CYP) enzymes.

2. CYP2C19 catalysed the demethylation with apparent K_m and V_max values of 373.4 ± 45.1?μM and 6.0 ± 0.3?pmol?min^?1?pmol^?1 CYP, respectively (mean ± SD). Both CYP2D6 and HLM exhibited clear biphasic profiles with apparent K_m,1 values of 1.3 ± 0.4 and 22.0 ± 6.5?μM, respectively, and V_max,1 values of 1.1 ± 0.1 pmol?min^?1?pmol^?1 CYP and 169.1 ± 20.5?pmol?min^?1?mg^?1 protein, respectively.

3. Percentages of intrinsic clearances of MOPPP by particular CYPs were calculated using the relative activity factor (RAF) approach with (S)-mephenytoin-4′-hydroxylation or bufuralol-1′-hydroxylation as index reactions for CYP2C19 or CYP2D6, respectively.

4. MOPPP, HO-PPP and the standard 3′,4′-methylenedioxy-pyrrolidinopropio-phenone (MDPPP) were separated and analysed by liquid chromatography–mass spectrometry in the selected-ion monitoring (SIM) mode.

5. The CYP2D6 specific chemical inhibitor quinidine (3?μM) significantly (?p<0.0001) inhibited HO-PPP formation by 91.8 ± 0.5% (mean ± SEM) in incubation mixtures with HLM and 2?μM MOPPP.

6. It can be concluded from the data obtained from kinetic and inhibition studies that polymorphically expressed CYP2D6 is the enzyme mainly responsible for MOPPP demethylation.     

Influence of CYP2C19 and ABCB1 polymorphisms on plasma concentrations of lansoprazole enantiomers after enteral administration

1. An intraoral annihilation enteric-coated preparation of lansoprazole is often administered via intestinal fistula. The purpose of this study was to determine the plasma concentrations of lansoprazole enantiomers after enteral administration in subjects with cytochrome P4502C19 (CYP2C19) and ABCB1 C3435T genotypes.

2. Fifty-one patients who underwent a curative oesophagectomy for oesophageal cancer were enrolled in this study. After a single enteral dose of racemic lansoprazole (30?mg), plasma concentrations of lansoprazole enantiomers were measured 4?h post-dose (C_4h).

3. There were significant differences in the C_4h of (R)- and (S)-lansoprazole and the R/S-enantiomer ratio for three CYP2C19 genotype groups (*1/*1, *1/*2 ± *1/*3, and *2/*2 ± *2/*3 ± *3/*3 (poor metabolizers (PMs)), but not the ABCB1 C3435T genotypes. In a stepwise forward selection multiple regression analysis, the C_4h of (R)- and (S)-lansoprazole were associated with CYP2C19 PMs (p?=?0.0005 and < 0.0001 respectively) and age (p?=?0.0040 and 0.0121 respectively), while the R/S-enantiomer ratio was associated with CYP2C19*1/*1 (p?=?0.0191) and CYP2C19 PMs (p?=?0.0426).

4. Direct administration to the jejunum is unaffected by residence time in the stomach and the gastric emptying rate. With enteral administration, CYP2C19 phenotyping of patients using the lansoprazole R/S enantiomer index at C_4h could be possible.

     

24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain

ABSTRACT

Background: Collagen hydrolysate is a nutritional supplement that has been shown to exert an anabolic effect on cartilage tissue. Its administration appears beneficial in patients with osteoarthritis.

Objective: To investigate the effect of collagen hydrolysate on activity-related joint pain in athletes who are physically active and have no evidence of joint disease.

Design and setting: A prospective, randomized, placebo-controlled, double-blind study was conducted at Penn State University in University Park, Pennsylvania. Parameters including joint pain, mobility, and inflammation were evaluated with the use of a visual analogue scale during a 24-week study phase.

Study participants: Between September 2005 and June 2006, 147 subjects who competed on a varsity team or a club sport were recruited. Data from 97 of 147 subjects could be statistically evaluated.

Intervention: One hundred and forty-seven subjects (72 male, 75 female) were randomly assigned to two groups: a group (n?=?73) receiving 25?mL of a liquid formulation that contained 10?g of collagen hydrolysate (CH-Alpha)^* and a group (n?=?74) receiving a placebo, which consisted of 25?mL of liquid that contained xanthan.

Main outcome measures: The primary efficacy parameter was the change in the visual analogue scales from baseline during the study phase in relation to the parameters referring to pain, mobility, and inflammation.

Results: When data from all subjects (n?=?97) were evaluated, six parameters showed statistically significant changes with the dietary supplement collagen hydrolysate (CH) compared with placebo: joint pain at rest, assessed by the physician (CH vs. placebo (–1.37?±?1.78 vs. –0.90?±?1.74 (?p?=?0.025)) and five parameters assessed by study participants: joint pain when walking (–1.11?±?1.98 vs. –0.46?±?1.63, p?=?0.007), joint pain when standing (–0.97?±?1.92 vs. –0.43?±?1.74, p?=?0.011), joint pain at rest (–0.81?±?1.77 vs. –0.39?±?1.56, p?=?0.039), joint pain when carrying objects (–1.45?±?2.11 vs. –0.83?±?1.71, p?=?0.014) and joint pain when lifting (–1.79?±?2.11 vs. –1.26?±?2.09, p?=?0.018). When a subgroup analysis of subjects with knee arthralgia (n?=?63) was performed, the difference between the effect of collagen hydrolysate vs. placebo was more pronounced. The parameter joint pain at rest, assessed by the physician, had a statistical significance level of p?=?0.001 (–1.67?±?1.89 vs. –0.86?±?1.77), while the other five parameters based on the participants’ assessments were also statistically significant: joint pain when walking (?p?=?0.003 (– 1.38?±?2.12 vs. – 0.54?±?1.65)), joint pain when standing (?p?=?0.015 (–1.17?±?2.06 vs. –0.50?±?1.68)), joint pain at rest with (?p?=?0.021 (–1.01 ±1.92 vs. –0.47?±?1.63)), joint pain when running a straight line (?p?=?0.027 (–1.50?±?1.97 vs. –0.80?±?1.66)) and joint pain when changing direction (?p?=?0.026 (–1.87?±?2.18 vs. –1.20?±?2.10)).

Conclusion: This was the first clinical trial of 24-weeks duration to show improvement of joint pain in athletes who were treated with the dietary supplement collagen hydrolysate. The results of this study have implications for the use of collagen hydrolysate to support joint health and possibly reduce the risk of joint deterioration in a high-risk group. Despite the study's size and limitations, the results suggest that athletes consuming collagen hydrolysate can reduce parameters (such as pain) that have a negative impact on athletic performance. Future studies are needed to support these findings.     

Prevention of arsenic-mediated reproductive toxicity in adult female rats by high protein diet

Abstract

Context: The detrimental effects of arsenic on female reproductive functions may involve overt oxidative stress. Casein and pea [Pisum sativum Linn. (Fabaceae)] proteins have antioxidant properties.

Objective: To investigate the role of casein- and pea-supplemented high-protein diet (HPD) in utero-ovarian protection from arsenic toxicity.

Materials and methods: Adult female Wistar rats were orally gavaged with vehicle (Gr-I) or arsenic at 3?ppm/rat/d (Gr-II and Gr-III) for 30 consecutive days, when they were maintained on either regular diet containing 18% protein (Gr-I and Gr-II), or HPD containing 27% protein in the form of casein (20%) and pea (7%) (Gr-III). Reproductive functions were evaluated using a battery of biochemical and histological techniques.

Results: As compared to Gr-I, the Gr-II rats suffered from loss of estrous cyclicity, reduction in weight (mg/100?g body weight) of ovary (Gr-I: 54.3?±?4.2 versus Gr-II: 35.8?±?1.6; p?<?0.001) and uterus (Gr-I: 161.7?±?24.6 versus Gr-II: 94.44?±?13.2; p?<?0.05), utero-ovarian degeneration, attenuated ovarian activities (unit/mg tissue/h) of Δ⁵, 3β-hydroxysteroid dehydrogenase (Gr-I: 3.41?±?0.12 versus Gr-II: 2.31?±?0.09; p?<?0.01) and 17β-hydroxysteroid dehydrogenase (Gr-I: 3.82?±?0.57 versus Gr-II: 1.24?±?0.19; p?<?0.001), and decreased serum estradiol level (pg/ml) (Gr-I: 61.5?±?2.06 versus 34.1?±?2.34; p?<?0.001). Ovarian DNA damage was preponderant with blatant generation of malondialdehyde (nM/mg tissue; Gr-I: 15.10?±?2.45 versus Gr-II: 29.51?±?3.44; p?<?0.01) and attenuated superoxide dismutase activity (unit/mg tissue) (Gr-I: 2.18?±?0.19 versus Gr-II: 1.33?±?0.18; p?<?0.05). The Gr-III rats were significantly protected from these ill effects of arsenic.

Discussion and conclusion: HPD, by way of antioxidant properties, may find prospective role in the protection of reproductive damage caused by arsenic.     

The value of post-marketing medication surveys in Parkinson's disease

ABSTRACT

Objective: In previous studies, the I₁ imidazoline specific agonist rilmenidine effectively lowered office blood pressure (BP) in patients with metabolic syndrome, improved glucose metabolism and did not demonstrate unfavourable effects on plasma lipids. The aim of the present study was to investigate the effects of 12?weeks’ therapy with rilmenidine compared with the ACE inhibitor lisinopril on ambulatory BP, plasma lipid and fasting glucose levels in women with metabolic syndrome.

Research design: Prospective randomised open-label, blinded end-points study.

Methods: Female patients (n = 51) with hypertension and other components of metabolic syndrome were treated with 1?mg rilmenidine (n = 24) or 10?mg lisinopril (n = 27), once- or twice-daily. Anthropometric measurements, office BP and heart rate (HR) measurements, ambulatory BP monitoring, lipid and fasting glucose assessment were performed before and after 12?weeks of treatment.

Main outcome measures: Changes in ambulatory BP and HR, including 24-h, daytime and night-time values, and in lipids and glucose levels. All changes were adjusted for baseline values using the analysis of covariance method.

Results: Ambulatory 24-h systolic BP and diastolic BP were decreased significantly in the rilmenidine group (–11.9 ± 1.9 and –7.7 ± 0.8?mm Hg, p < 0.001) respectively and the lisinopril group (–11.0 ± 1.8 and –6.7 ± 0.7?mm Hg respectively, p < 0.001). There were no significant differences between the two groups. Rilmenidine reduced 24-h ambulatory HR (–3.6 ± 0.8?bpm versus 0.3 ± 0.8?bpm with lisinopril; p = 0.002). The reductions of day-time and night-time BP were also significant for both treatment groups, but the rilmenidine group demonstrated a greater decrease in night-time diastolic BP (?p = 0.046). Rilmenidine significantly increased HDL cholesterol and decreased fasting glucose levels (?p = 0.009 and p = 0.012, respectively). HDL cholesterol tended to increase and fasting glucose tended to decrease in the lisinopril group. However, differences between groups were not significant.

Conclusion: Rilmenidine has similar effects on ambulatory BP patterns in hypertensive women with metabolic syndrome as lisinopril. Rilmenidine compared with lisinopril significantly reduces ambulatory HR. In this study, rilmenidine and lisinopril demonstrate similar effects on plasma lipid and fasting glucose levels.     

A comparison of teriparatide and calcitonin therapy in postmenopausal Asian women with osteoporosis: a 6‐month study

ABSTRACT

Objective: The number of hip fractures is expected to double in the next 20 years, with current estimates that Asia will account for 37% of these cases. As bone mineral density (BMD) may be used as a measure of fracture risk, we sought to compare the effects of teriparatide with salmon calcitonin treatment on changes in BMD, biochemical bone markers, and safety in postmenopausal Asian women with osteoporosis.

Methodology: A total of 104 patients (?n = 47 teriparatide [20?µg/day subcutaneously] and n = 57 calcitonin [100?IU/day subcutaneously]) were enrolled in Hong Kong, Singapore, Philippines, Malaysia, and Thailand. Calcium (≥ 500?mg/day) and vitamin D (200–400?IU/day) supplements were taken throughout the 6‐month controlled, randomized study.

Results: Teriparatide was associated with a 5.03 ± 4.77% increase in lumbar spine BMD (?p < 0.0001, mean ± SD change from baseline), whereas changes in lumbar spine BMD for patients on calcitonin were not statistically significant (mean change of 0.36 ± 4.12%, p = 0.16). Comparison of the two groups indicated that teriparatide treatment improved lumbar spine BMD statistically significantly more than calcitonin (?p < 0.0001). No statistically significant changes were observed for total hip or femoral neck BMD. Serum bone-specific alkaline phosphatase (BSAP) increased by 55.9% (median change from baseline, p < 0.0001) in the teriparatide group, and remained stable with calcitonin (5.0% change, p = 0.24); osteocalcin increased by 156.15% (median change from baseline, p < 0.0001) with teriparatide, and decreased with calcitonin (–15.25%, p = 0.03). Similar rates of adverse events were observed, with nausea and dizziness the most commonly reported for both groups (teriparatide versus calcitonin, 13.0% versus 23.2% p = 0.21, 10.9% versus 21.4% p = 0.19, respectively). There were no clinically relevant changes observed in laboratory parameters.

Conclusions: Both treatments were similarly tolerated, however teriparatide was associated with greater increases in lumbar spine BMD and bone formation markers, demonstrating the unique mechanism of action and safety of this treatment for osteoporosis in these Asian women.     

Inhibitory effect of TGF-β peptide antagonist on the fibrotic phenotype of human hypertrophic scar fibroblasts

Context: TGF-β plays a central role in hypertrophic scar (HS) formation and development.

Objective: This study investigated the role of a TGF-β antagonist peptide in inhibiting fibrotic behavior of human HS-derived fibroblasts (HSFs).

Materials and methods: HSFs were seeded at a density of 3.1?×?10⁴/cm² and were subjected to treatment of peptide antagonist (30?μM) or TGF-β receptor inhibitor LY2109761 (10?μM) or without treatment followed by the analyses of quantitative PCR, Elisa, in vitro wounding and fibroblast-populated collagen lattice (FPCL) assays.

Results: qPCR and Elisa analyses showed that the peptide could, respectively, reduce the gene (at 48?h) and protein (at 72?h) expression levels of collagen I (86?±?4.8%; 56.6?±?7.3%), collagen III (73?±?10.7%; 43.7?±?7.2%), fibronectin (90?±?8.9%; 21.1?±?2.8%), and TGF-β1 (85?±?9.3%; 25.0?±?9.4%) as opposed to the non-treated group (p?<?0.05), as the LY2109761 group similarly did. Cell proliferation was also significantly inhibited at day 5 (CCK-8 assay) by both peptide and LY2109761 treatments compared with the non-treated group (p?<?0.05). The peptide also significantly inhibited cell migration as opposed to blank control at 24?h (43?±?6.7% versus 60?±?2.1%, p?<?0.05) and at 48?h (63.9?±?3.1% versus 95?±?4.1%, p?<?0.05). Similar to LY2109761, the peptide antagonist significantly reduced HS FPCL contraction compared with the non-treated group with significant differences in surface area at 48?h (0.71?±?0.06?cm² versus 0.51?±?0.06?cm², p?<?0.05) and at 72?h (0.65?±?0.02?cm² versus 0.42?±?0.01?cm², p?<?0.05).

Conclusion: The TGF-β antagonist peptide may serve as an important drug for HS prevention and reduction given the obvious benefits of good biosafety, low cost, and easy manufacture and delivery.     

Synthesis and the Stereoselective Enzymatic Hydrolysis of Flurbiprofen-Basic Amino Acid Ethyl Esters

Abstract

Ethyl esters of flurbiprofen L-arginine (FP-Arg-OH), flurbiprofen L-lysine (FP-Lys-OH) and flurbiprofen p-guanidino-L-phenylalanine (FP-GPA-OH) were synthesized and then the release of flurbiprofen enantiomers from these derivatives in the presence of trypsin (Tp), carboxypeptidase B (CPB) and car-boxypeptidase Y (CPY) were examined in order to evaluate their availability as prodrugs for flurbiprofen (FP). The ester bonds of the three racemic FP derivatives were hydrolyzed by Tp at about 3 to 20 times the rates of N-benzoyl-L-arginine ethyl ester (Bz-Arg-OEt), a specific substrate for Tp. (R)- FP was released faster than (S)-FP by either CPB or CPY from both FP-Arg-OH and FP-Lys-OH. On the other hand, FP-GPA-OH was not hydrolyzed at all by CPB and the hydrolysis rate of this compound by CPY was very slow. (S)-Flurbiprofen L-arginine ethyl ester ((S)-FP-Arg-OEt) was separated from (R)-FP-Arg-OEt by high-performance liquid chromatography. A comparison of the kinetic parameters for the tryptic hydrolysis of the two optically active FP-Arg-OEt diastereomers and those of Bz-Arg-OEt suggested that the orientation of the scissile bond in each diastereomer to the catalytic center of Tp is more favorable than that of Bz-Arg-OEt. However, no significant difference was found between the kinetic parameters for the two diastereomers, suggesting that the orientational difference between (S)-FP and (R)-FP in the diastereomers does not have any effect on the tryptic hydrolysis of the ester bond. On the other hand, for the hydrolysis of the diastereomers by CPB and CPY, the kcat values for (R)-FP-Arg-OH were larger than those for (S)-FP-Arg-OH, while the Km values for the former were almost the same as those for the latter. These results indicate that the orientation of the scissile bond in (R)-FP-Arg-OH to the catalytic sites of CPB and CPY was more favorable than that in (S)-FP-Arg-OH. (S)-FP-Arg-OEt is thus considered to be a promising optically active water-soluble prodrug for the sustained release of FP.     

Exenatide effects on diabetes,obesity, cardiovascular risk factors and hepatic biomarkers in patients with type 2 diabetes treated for at least 3 years

ABSTRACT

Background: Exenatide, an incretin mimetic for adjunctive treatment of type 2 diabetes (T2DM), reduced hemoglobin A_1c (A1C) and weight in clinical trials. The objective of this study was to evaluate the effects of?≥?3 years exenatide therapy on glycemic control, body weight, cardiometabolic markers, and safety.

Methods: Patients from three placebo-controlled trials and their open-label extensions were enrolled into one open-ended, open-label clinical trial. Patients were randomized to twice daily (BID) placebo, 5?µg exenatide, or 10?µg exenatide for 30 weeks, followed by 5?µg exenatide BID for 4 weeks, then 10?µg exenatide BID for ≥3 years of exenatide exposure. Patients continued metformin and/or sulfonylureas.

Results: 217 patients (64% male, age 58?±?10 years, weight 99?±?18?kg, BMI 34?±?5?kg/m², A1C 8.2?±?1.0% [mean?±?SD]) completed 3 years of exenatide exposure. Reductions in A1C from baseline to week 12 (?1.1?±?0.1% [mean?±?SEM]) were sustained to 3 years (?1.0?±?0.1%; p?<?0.0001), with 46% achieving A1C?≤?7%. Exenatide progressively reduced body weight from baseline (?5.3?±?0.4?kg at 3 years; p?<?0.0001). Patients with elevated serum alanine aminotransferase (ALT) at baseline (n?=?116) had reduced ALT (?10.4?±?1.5?IU/L; p?<?0.0001) and 41% achieved normal ALT. Patients with elevated ALT at baseline tended to lose more weight than patients with normal ALT at baseline (?6.1?±?0.6?kg vs. ?4.4?±?0.5?kg; p?=?0.03), however weight change was minimally correlated with baseline ALT (r?=??0.01) or ALT change (r?=?0.31). Homeostasis Model Assessment B (HOMA-B), blood pressure, and aspartate aminotransferase (AST) all improved. A subset achieved 3.5 years of exenatide exposure and had serum lipids available for analysis (n?=?151). Triglycerides decreased 12% (p?=?0.0003), total cholesterol decreased 5% (p?=?0.0007), LDL-C decreased 6% (p?<?0.0001), and HDL-C increased 24% (p <?0.0001). Exenatide was generally well tolerated. The most frequent adverse event was mild-to-moderate nausea. The main limitation of this study is the open-label, uncontrolled nature of the study design which does not provide a placebo group for comparison.

Conclusion: Adjunctive exenatide treatment for ≥3 years in T2DM patients resulted in sustained improvements in glycemic control, cardiovascular risk factors, and hepatic biomarkers, coupled with progressive weight reduction.     

Influence of switching to travoprost on intraocular pressure of uncontrolled chronic open-angle glaucoma patients compliant to previously-used topical medication

ABSTRACT

Objective: To investigate the influence of switching to travoprost on intraocular pressure (IOP) of chronic open-angle glaucoma (COAG) patients.

Research design and methods: Multicentre, open-label, non-comparative, 12‐week, phase IV study conducted at 10 academic and hospital centres in Hungary. Patients’ compliance to use of the pre-study medication was confirmed at a visit 10 days before the baseline measurements, and compliance was monitored throughout the study period.

Results: Of the 203 COAG patients three (1.48%) ceased travoprost medication due to ocular hyperaemia, and one subject was lost from follow-up. Self-reported compliance was optimal except for two patients. For the per-protocol analysis 197 patients were evaluable. IOP of the 37 per-protocol patients receiving additional travoprost medication decreased from 23.1 ± 3.2?mmHg (mean ± SD) to 17.3 ± 2.6?mmHg at week 12 (?p < 0.001). Switching the 121 per-protocol patients from latanoprost to travoprost IOP decrease from 20.8 ± 3.5?mmHg to 17.7 ± 2.4?mmHg (?p < 0.001). IOP of the 11 patients switched from topical non-selective beta-blockers to travoprost decreased from 20.1 ± 2.1?mmHg to 15.7 ± 1.5?mmHg (?p < 0.001). For the whole per-protocol population (n = 197) IOP decreased from 21.0 ± 3.4?mmHg to 17.4 ± 2.4?mmHg (?p < 0.001). Defining responders as having an IOP decrease > 2.0?mmHg or ≥ 5?mmHg at week 12, the responder rate was respectively 62.9% or 31% for the total study population; 86.5% or 54.1% when travoprost was added to the established therapy; 54.5% or 24.0% if latanoprost was switched to travoprost; and 90.9% or 36.4% for those who switched from beta-blockers.

Conclusion: Travoprost provided a clinically and statistically significant IOP decrease in uncontrolled COAG patients whose self-reported compliance to their previous topical medication was optimal. Our results suggest that the IOP reduction found after switching to travoprost is not explainable by improved compliance due to the clinical study situation.     

Hospitalization rates before and after initiation of paliperidone ER in patients with schizophrenia: results from open-label extensions of the US double-blind trials

ABSTRACT

Objective: To assess differences in the number of days hospitalized among schizophrenic patients receiving paliperidone extended-release (paliperidone ER) during the open-label extension (OLE) phases, compared to a similar time period prior to the screening for entry into the double-blind (DB) trials conducted in the United States.

Methods: Mental health-related hospital days during the 52 weeks before entering the DB trials and during the OLE phases were compared. The mean number of hospital days per person per year in the pre- and post-periods was calculated and the statistical significance of pre-post differences was assessed using bootstrap resampling methods. Total person-years were also calculated for the pre- and post-periods to account for different lengths of observation.

Results: Patients' (n = 215) mean (?±?SD) age was 41.2 (?±?11.0) years; most were male (73.0?%?); and black (52.1 vs. 45.1?%?white). The mean (?±?SD) paliperidone ER treatment duration during the OLE phase was 167.0 (?±?145.0) days and the mean (?±?SD) daily dose was 10.5 (?±?2.0) mg. Overall, paliperidone ER patients spent an average (?±?SD) of 13.2 (?±?1.6) and 3.1 (?±?0.7) hospital days per person-year in the pre-and post-periods, respectively (mean?±?SD change 10.0?±?1.8, 95?%?CI 6.5, 13.4, p?<?0.001). Using the 2007 Federal Per Diem Base Rate (i.e., $595.09 per day), this reduction in hospital days would result in an average (?±?SD) cost savings of $5951 (?±?1071) per person per year.

Conclusions: Patients had significantly fewer hospital days in the OLE phase compared to the 1-year period prior to entering the DB trial. Paliperidone ER may play a role in reducing mental health-related hospital days and associated costs. Important study limitations include the lack of a control group, the pre-post design comparing historical data with data collected in the trials which could create a bias due to the mismatch in settings, and patients having more frequent contact with treating physicians and investigators during the trial period, which could favor the outcomes in the OLE phase. Further studies are needed to confirm these findings.     

Brimonidine purite 0.1% versus brinzolamide 1% as adjunctive therapy to latanoprost in patients with glaucoma or ocular hypertension

ABSTRACT

Objective: To evaluate the efficacy and tolerability of brimonidine purite 0.1% in comparison to brinzolamide 1% when used as adjunctive therapy to latanoprost 0.005% in patients with glaucoma or ocular hypertension.

Methods: Randomized, single-center, investigator-masked, parallel-group clinical study. Patients with IOP?≥?18?mmHg while on once-daily latanoprost were randomized to adjunctive treatment with brimonidine purite TID (n?=?20) or brinzolamide TID (n?=?20) for 3 months. Intraocular pressure (IOP) was measured at 8 a.m., 10 a.m., and 4 p.m. at latanoprost-treated baseline and after 1 and 3 months of latanoprost and adjunctive therapy. A patient questionnaire was administered to evaluate the tolerability of eye drop instillation.

Results: Baseline mean diurnal IOP (± standard deviation, mmHg) on latanoprost was comparable between groups (brimonidine purite: 19.6?±?2.94; brinzolamide: 19.8?±?3.25; p = 0.846). Mean diurnal IOP at Month 3 was 16.3?±?2.63?mmHg with brimonidine purite and 17.8?±?2.19?mmHg with brinzolamide (?p = 0.028). Adjunctive use of brimonidine purite provided greater IOP lowering than brinzolamide at 10 a.m. (?p < 0.001) and 4 p.m. (?p = 0.050) and equivalent IOP lowering to brinzolamide at 8 a.m. (?p = 0.716). Blurred vision at Month 1 and bitter taste at Months 1 and 3 were more common upon instillation of brinzolamide eye drops.

Conclusion: Brimonidine purite 0.1% provided significantly lower IOP compared with brinzolamide 1% when used as adjunctive therapy to latanoprost. Both adjunctive therapies were well tolerated. Limitations of this study include the use of a single site and the sample size. Additional studies are needed to further evaluate these drugs as adjunctive therapy to prostaglandin analogs.     

Effect of pramlintide as an adjunct to basal insulin on markers of cardiovascular risk in patients with type 2 diabetes

ABSTRACT

Objective: Intensification of insulin therapy in patients with type 2 diabetes, while improving glycemic control, often leads to an increase in body weight and other markers of cardiovascular risk. The effects of pramlintide as an adjunct to basal insulin titration (without mealtime insulin) on glycemia and cardiovascular risk markers were examined.

Research design and methods: This was a post hoc analysis of a 16-week, double-blind, placebo-controlled study in patients with type 2 diabetes (N?=?211) using insulin glargine (without mealtime insulin)?±?oral agents. Patients were randomized to treatment with placebo or pramlintide (60 or 120?µg with major meals), and insulin glargine was titrated to target a fasting plasma glucose concentration of ≥70 to <100?mg/dL.

Main outcome measures: Endpoints included the change from baseline to Week 16 in body weight, high sensitivity C-reactive protein (hsCRP), triglycerides, HDL, LDL, and blood pressure.

Results: Pramlintide-treated patients lost weight and placebo-treated patients gained weight during 16 weeks of treatment (?1.6?±?0.3?kg vs. +0.7?±?0.3?kg, p?<?0.001; mean?±?SE). hsCRP was reduced in pramlintide-treated versus placebo-treated patients (?0.8?±?0.2?mg/L vs. 0.1?±?0.2?mg/L, p?<?0.01; mean?±?SE). Patients with baseline hsCRP?>?3?mg/L (high cardiovascular risk) demonstrated greater hsCRP reductions with pramlintide versus placebo treatment at Week 16 (p?<?0.05). Patients with baseline triglycerides ≥150?mg/dL or ≥200?mg/dL (high cardiovascular risk) showed significant reductions from baseline in triglyceride concentrations with pramlintide (?43?±?14?mg/dL or ?59?±?19?mg/dL; p?<?0.05; mean?±?SE) but not with placebo (1?±?29?mg/dLor ?3?±?54?mg/dL; mean?±?SE). No significant differences between pramlintide and placebo were observed for changes in HDL, LDL, or blood pressure. Pramlintide treatment was generally well tolerated. The most frequent adverse event related to pramlintide was mild-to-moderate nausea (31% pramlintide vs. 10% placebo). Pramlintide added to basal insulin did not increase the incidence of hypoglycemia. A limitation of the study was its relatively short duration.

Conclusions: Pramlintide, as an adjunct to basal insulin, was associated with improvements in several cardiovascular risk markers, warranting long-term clinical studies to determine its potential effects on cardiovascular risk.     

Effects of exenatide versus sitagliptin on postprandial glucose,insulin and glucagon secretion,gastric emptying,and caloric intake: a randomized,cross-over study

ABSTRACT

Background: This study evaluated the effects of exenatide, a GLP-1 receptor agonist, and sitagliptin, a DPP-4 inhibitor, on 2-h postprandial glucose (PPG), insulin and glucagon secretion, gastric emptying, and caloric intake in T2D patients.

Methods: This double-blind, randomized cross-over, multi-center study was conducted in metformin-treated T2D patients: 54% female; BMI: 33?±?5?kg/m²; HbA_1c: 8.5?±?1.2%; 2-h PPG: 245?±?65?mg/dL. Patients received exenatide (5?µg BID for 1 week, then 10?µg BID for 1 week) or sitagliptin (100?mg QAM) for 2 weeks. After 2 weeks, patients crossed-over to the alternate therapy. Postprandial glycemic measures were assessed via standard meal test; caloric intake assessed by ad libitum dinner (subset of patients). Gastric emptying was assessed by acetaminophen absorption (Clinicaltrials.gov Registry Number: NCT00477581).

Results: After 2 weeks of therapy, 2-h PPG was lower with exenatide versus sitagliptin: 133?±?6?mg/dL versus 208?±?6?mg/dL, p?<?0.0001 (evaluable, N?=?61). Switching from exenatide to sitagliptin increased 2-h PPG by +73?±?11?mg/dL, while switching from sitagliptin to exenatide further reduced 2-h PPG by ?76?±?10?mg/dL. Postprandial glucose parameters (AUC, C_ave, C_max) were lower with exenatide than sitagliptin (p?<?0.0001). Reduction in fasting glucose was similar with exenatide and sitagliptin (?15?±?4?mg/dL vs. ?19?±?4?mg/dL, p?=?0.3234). Compared to sitagliptin, exenatide improved the insulinogenic index of insulin secretion (ratio exenatide to sitagliptin: 1.50?±?0.26, p?=?0.0239), reduced postprandial glucagon (AUC ratio exenatide to sitagliptin: 0.88?±?0.03, p?=?0.0011), reduced postprandial triglycerides (AUC ratio exenatide to sitagliptin: 0.90?±?0.04, p?=?0.0118), and slowed gastric emptying (acetaminophen AUC ratio exenatide to sitagliptin: 0.56?±?0.05, p?<?0.0001). Exenatide reduced total caloric intake compared to sitagliptin (?134?±?97?kcal vs. +130?±?97?kcal, p?=?0.0227, N?=?25). Common adverse events with both treatments were mild to moderate in intensity and gastrointestinal in nature.

Conclusions: Although this study was limited by a 2-week duration of exposure, these data demonstrate that, exenatide had: (i) a greater effect than sitagliptin to lower postprandial glucose and (ii) a more potent effect to increase insulin secretion and reduce postprandial glucagon secretion in T2D patients. In contrast to sitagliptin, exenatide slowed gastric emptying and reduced caloric intake. These key findings differentiate the therapeutic actions of the two incretin-based approaches, and may have meaningful clinical implications.     

Comparison of enantioselective disposition of rabeprazole versus lansoprazole in renal-transplant recipients who are CYP2C19 extensive metabolizers

The purpose of this study was to investigate the comparative pharmacokinetics of rabeprazole and lansoprazole enantiomers in renal-transplant recipients on tacrolimus who were CYP2C19 extensive metabolizers. Sixteen Japanese patients were randomly assigned after renal transplantation to receive repeated doses of one of the following two regimens for 28 days; tacrolimus, mycophenolate mofetil and prednisolone together with either 20?mg of racemic rabeprazole (n?=?8) or 30?mg of racemic lansoprazole (n?=?8). The mean C_max and AUC_0–24 of (R)-lansoprazole compared to (S)-lansoprazole in renal transplant recipients were 12-fold (954?±?522 vs. 167?±?137?ng?ml^?1, respectively) and 6.9-fold (4787?±?3454 vs. 451?±?354?ng?h?ml^?1, respectively) greater, and its elimination half-life was 2.1-fold (2.3?±?1.0 vs. 1.2?±?0.6?h, respectively) longer. In contrast, although the elimination half-life of (R)-rabeprazole was significantly longer than that of the (S)-enantiomer (2.1?±?0.5 vs. 1.3?±?0.9?h, respectively; P?C_max between the (R)- and (S)-enantiomer (186?±?40 vs. 200?±?92?ng?ml^?1, respectively). In conclusion, in renal-transplant recipients who are CYP2C19 extensive metabolizers, there is less stereoselective difference in the pharmacokinetic disposition between the (R)- and (S)-enantiomers of rabeprazole than those of lansoprazole.     

Post-bedtime dosing with indiplon in adults and the elderly: results from two placebo-controlled,active comparator crossover studies in healthy volunteers

ABSTRACT

Objective: To assess the effects of post-bedtime dosing with indiplon on next-day function in adults and the elderly.

Research design and methods: Two randomized, double-blind, placebo-controlled crossover studies were conducted in two groups of healthy volunteers: an adult study (18–45 years) and an elderly study (65–80 years). In adults, a single post-bedtime dose of indiplon 10?mg and 20?mg was compared to placebo, with zolpidem 10?mg and zopiclone 7.5?mg included as controls. In the elderly, a single post-bedtime dose of indiplon 5?mg and 10?mg was compared to placebo, with zopiclone 3.75?mg included as a control. Next-day residual effects were evaluated in the morning at 4 and 6?h post-dose in adults, and 4, 6, and 8?h in the elderly, by a Visual Analog Scale of sleepiness (VAS-sleepiness), Digit Symbol Substitution Test (DSST), and the Symbol Copying Test (SCT).

Results: In adults, there were no statistically significant differences between indiplon and placebo on the VAS-sleepiness, DSST, or SCT at any timepoint for either dose. In contrast, a significant increase versus placebo in VAS-sleepiness was observed for both zopiclone (at 4 and 6?h post-dose; p < 0.0001 and p = 0.002, respectively) and zolpidem (at 4?h post-dose; p = 0.042). In the elderly, there were no statistically significant differences between indiplon 5?mg and placebo on the VAS-sleepiness, DSST, or SCT at any timepoint. DSST was significantly reduced for indiplon 10?mg versus placebo at 4?h only (?p = 0.022), compared with a significant reduction in DSST for zopiclone at both 4 and 8?h post-dose (?p = 0.002 and p = 0.003, respectively). In adults, the overall incidence of adverse events was higher on zopiclone compared to indiplon, zolpidem, and placebo. In the elderly, the incidence of adverse events was similar for indiplon, zopiclone, and placebo. Potential limitations of the current study include recruitment of healthy volunteers and the use of a limited pharmacodynamic battery.

Conclusions: Indiplon, at doses of 10?mg in adults and 5?mg in the elderly, was not associated with next day residual sedation or impairment in simple cognitive and psychomotor tasks when administered during the night 4?h prior to awakening.     

Patient characteristics,drug adherence patterns,and hypoglycemia costs for patients with type 2 diabetes mellitus newly initiated on exenatide or insulin glargine

ABSTRACT

Objective: Examine real-world effectiveness and hypoglycemia cost burden in patients with type?2 diabetes newly initiated on exenatide or insulin glargine.

Design and methods: Retrospective cohort study describing patient characteristics, drug adherence patterns, and 1-year hypoglycemia rates with associated costs using an administrative claims database. Adult subjects with type?2 diabetes had an initial claim for exenatide or insulin glargine between May?1, 2005 and June?30, 2007, and had continuous eligibility for ≥?6 months pre- and ≥?12 months post-initiation.

Results: The exenatide cohort (n?=?3262) was 53?±?10?years (±SD); 54% female. The insulin glargine cohort (n?=?3038) was 56?±?12?years; 41% female. The mean Deyo-Charlson comorbidity index score was 1.45 for exenatide versus 1.82 for insulin glargine (p?<?0.001). Baseline OAD use rates for exenatide and insulin glargine, respectively, were 77% versus 69% metformin; 47% versus 65% sulfonylurea; 50% versus 49% thiazolidinedione; 56% versus 60% multiple OAD. For patients with two or more pharmacy claims for exenatide or insulin glargine, the 12-month medication possession ratio (MPR) was 68?±?29% for exenatide and 58?±?28% for insulin glargine (p?<?0.001). MPR ≥?80% was higher for exenatide (p?<?0.001) and fewer patients discontinued therapy (p?<?0.001). The probability of a hypoglycemic event was significantly lower for exenatide (p?<?0.005), resulting in lower associated annual costs.

Conclusions: This study provides the first real-world observational comparison of type?2 diabetes patients newly initiated on exenatide or insulin glargine. Exenatide patients had a lower comorbidity burden, better drug adherence, and a lower rate of hypoglycemic events with associated costs. Retrospective database analyses examine medical care utilization in large populations using a relatively inexpensive and expedient approach. However, data are only representative of a commercial health-care plan with limited information on multiple variables usually collected during clinical trials.