Safety and effectiveness profile of raloxifene in long-term, prospective, postmarketing surveillance.

This large-scale postmarketing surveillance of raloxifene (60 mg/day) was conducted to assess the safety and effectiveness of raloxifene for long-term use in postmenopausal Japanese women with osteoporosis. The baseline examination included 6,967 women (mean age, 70.4 years). Participants completed observation after 6, 12, 24, and 36 months of therapy. Adverse drug reactions (ADR) were reported in 776 participants (11.14 %), with a total of 87 serious ADR cases occurring in 76 participants (1.09 %). The most frequently reported ADRs were edema peripheral (45/6,967, 0.65 %) and venous thromboembolism (11/6,967, 0.16 %). Of the 6,967 participants, 2,784 were included in the effectiveness analysis. Lumbar spine bone mineral density (BMD) increased significantly (p < 0.001, paired t test) compared with baseline at 6, 12, 24, and 36 months (2.51 %, 2.85 %, 4.76 %, and 3.51 %, respectively). Significant decreases in serum and urinary cross-linked amino-terminal telopeptide of type I collagen (NTX) and urinary deoxypyridinoline levels from baseline were observed at 3 months, followed by a significant decrease of serum bone alkaline phosphatase at 6 months [p < 0.001 for all comparisons except serum NTX (p = 0.011), Wilcoxon signed-rank test]. Early reductions in the biochemical markers of bone turnover (BTM) observed at 3 months with raloxifene treatment correlated negatively with subsequent increases in lumbar spine BMD at 1 year (r = -0.347, p = 0.008). The incidence of any new clinical fractures within 3 years was 1.18 % (82/6,967 participants). In summary, no new signals in safety were observed in the daily use of raloxifene. Moreover, the effectiveness profile of raloxifene was confirmed in practical use by this large-scale, long-term, postmarketing surveillance.

Vertebral fracture status and the World Health Organization risk factors for predicting osteoporotic fracture risk in Japan.

INTRODUCTION: Vertebral fractures are the most common osteoporotic fracture and the prevalence of vertebral fracture is commonly assessed in clinical practice in Japan. The objective of this study was to evaluate potential risk factors for osteoporotic fractures, including morphometric spine fracture status and the WHO risk factors for predicting 4-year fracture risk. METHODS: A population-based community cohort, the Adult Health Study, consisting of 2613 men and women with mean age of 65 enrolled in Hiroshima was followed prospectively for 4 years. The prevalence and incidence of spine fractures were identified from lateral and posterior-anterior spine radiographs using a semiquantitative method. Information on incident nonvertebral fragility fractures (hip, proximal humeral, and forearm) was collected at interviews by trained nurses and physicians during biennial health examinations. RESULTS: A model, including spine fracture status in addition to the WHO risk factors, appeared to provide greater prognostic information regarding future fracture risk (gradient of risk/standard deviation: GR/SD=2.73) than a model with the WHO risk factors alone (GR/SD=2.54). In univariate analyses, age, bone mineral density (BMD), prior clinical fracture, and spine fracture status had the highest gradient of risk. The presence of multiple prevalent spine or non-spine fractures significantly increased fracture risk, but, their contributions to the gradient of risk were similar to those when fracture status was categorized as a binary variable. A model considering those four risk factors yielded GR/SD=2.67, indicating that it could capture most of the predictive information provided by the model with spine fracture status plus the WHO risk factors. CONCLUSION: The use of age, BMD, prior clinical fracture and spine fracture predicted future fracture risk with greater simplicity and higher prognostic accuracy than consideration of the risk factors included in the WHO tool.

Improved glycemic control and reduced bodyweight with exenatide: A double-blind, randomized, phase 3 study in Japanese patients with suboptimally controlled type 2 diabetes over 24 weeks.

UNLABELLED: Aims/Introduction: To evaluate the efficacy and safety of the glucagon-like peptide-1 receptor agonist, exenatide, in Japanese patients with type 2 diabetes mellitus suboptimally controlled despite therapeutic doses of a sulfonylurea alone or combined with a biguanide or thiazolidinedione. MATERIALS AND METHODS: Patients were randomized to a placebo or exenatide, either 5 or 10 µg, given subcutaneously b.i.d. in addition to oral therapy. Patients randomized to 10 µg exenatide received 5 µg b.i.d. for the first 4 weeks, followed by 10 µg b.i.d. for the last 20 weeks. RESULTS: A total of 179 patients received the study drug and composed the full analysis set (n = 35, placebo; n = 72, exenatide 5 µg; n = 72, exenatide 10 µg; 68% male; 58 ± 10 years; body mass index 25.5 ± 4.1 kg/m(2); HbA1c 8.2 ± 0.9%; means ± standard deviations). Baseline to end-point (least-squares means ± standard errors) HbA1c changes (%) were -0.28 ± 0.15 (placebo), -1.34 ± 0.11 (exenatide 5 µg) and -1.62 ± 0.11 (exenatide 10 µg) (both P < 0.001, exenatide vs placebo). Baseline to end-point bodyweight changes (kg) were -0.47 ± 0.39 (placebo), -0.39 ± 0.28 (exenatide 5 µg) and -1.54 ± 0.27 (exenatide 10 µg; P = 0.026, exenatide 10 µg vs placebo). Nausea, generally mild to moderate, was reported in 8.6% (placebo), 25.0% (exenatide 5 µg) and 36.1% (exenatide 10 µg) of patients. Mild to moderate hypoglycemia was reported in 22.9% (placebo), 51.4% (exenatide 5 µg) and 58.3% (exenatide 10 µg) of patients. CONCLUSIONS: Over 24 weeks, exenatide vs the placebo improved glycemic control, reduced bodyweight (10 µg) and was well tolerated in Japanese patients with type 2 diabetes mellitus suboptimally controlled, despite oral therapy including a sulfonylurea. This trial was registered with ClinicalTrials.gov (no. NCT00577824). (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00084.x, 2011).

Amelioration of endothelin-1-induced optic nerve head ischemia by topical bunazosin.

PURPOSE: To investigate the effects of bunazosin hydrochloride, an alpha1-adrenergic blocker, on the impairment of optic nerve head (ONH) blood flow and depression of visual function induced by repeated intravitreal injections of endothelin-1 (ET-1) in rabbits. METHOD: We injected ET-1 (20 pmol) into the right posterior vitreous of rabbits twice a week for 4 weeks, and the observation period was set at 8 weeks (starting the first injection). The animals that received ET01 were divided into two groups: twice a day for 8 weeks, o ne group received topical 0.01% bunazosin, while the second received the vehicle for bunazosin. The ONH blood flow was monitored using the laser speckle method, and visual function was assessed by examining visually evoked potentials (VEPs). Changes in the ONH cup/disk area and in the number of cells in the retinal ganglion cell layer (CCL) were also determined. RESULTS: Repeated injections of ET-1 decreased the ONH blood flow, prolonged the VEP implicit time, enlarged the optic cup, and decreased the number of GCL cells. Topical bunazosin significantly decreased these impairments. CONCLUSIONS: These results indicate that in rabbits, topical bunazosin suppresses the changes in ONH circulation and function induced by intravitreal ET-1.

Effects of adenosine on optic nerve head circulation in rabbits.

This study was performed to determine whether intravitreal or intravenous adenosine can alter the microcirculation in the optic nerve head (ONH) of rabbits. Capillary blood flow in the ONH was measured serially with a laser speckle tissue analyser for 2 hr after the intravitreal (0.1, 1.0 and 10 nmol) or intravenous (0.2 and 0.6 mg kg(-1)min) injections of adenosine. In addition, the effect of specific adenosine A(1) and A(2a) antagonists and an adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channel blockers on the adenosine-induced changes on the ONH blood flow was analysed. Intravitreal adenosine increased the capillary blood flow in the ONH in a dose-dependent manner, while intravenous adenosine had no effect. Co-administration of the specific adenosine A(1) receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 10 nmol) significantly suppressed (P=0.006, ANOVA) the increase in the ONH blood flow induced by adenosine (10 nmol). The specific A(2a) receptor antagonist, 8-(3-chlorostyryl) caffeine (CSC, 10 nmol), had a weak effect in inhibiting the increase but the change was not significant (P=0.08, ANOVA). Both specific A(1) and A(2a) receptor agonists, N(6)-cyclopentyladenosine (CPA, 10 nmol) and 2-p-(2-carboxyethyl) phenethyl-amino-5'-N-ethylcarboxamidoadenosine (CGS-21680, 10 nmol), increased the ONH tissue blood flow (P<0.01, ANOVA). Glibenclamide (10 nmol), a selective K(ATP) channels antagonist, suppressed the increase of ONH blood flow induced by 10 nmol adenosine significantly (P<0.001, ANOVA). On the other hand, 10 nmol of 8-Br-cAMP, a cAMP analog, failed to enhance the capillary blood flow in the ONH. These results indicate that adenosine increases the capillary blood flow in the ONH of rabbits, and it acts through A(1) and A(2a) receptors from the ablumenal side where pericytes are located. Activation of K(ATP) channels is strongly related to the mechanism of adenosine-induced increase in ONH blood flow, while the participation of adenylate cyclase is less likely.

Bunazosin hydrochloride reduces glutamate-induced neurotoxicity in rat primary retinal cultures.

To study neuroprotective effects of bunazosin hydrochloride which is an alpha(1)-adrenoceptor antagonist used as an ocular hypotensive drug compared to other alpha(1)-adrenoceptor antagonists, and its mechanism of action. We evaluated the neuroprotective effects of bunazosin hydrochloride or seven other alpha(1)-adrenoceptor antagonists against glutamate-induced cell death in rat primary retinal cultures. We also evaluated the binding inhibition of bunazosin hydrochloride for 24 different receptors/channels and its effects on the Na(+) influx into cells induced by veratridine or glutamate. Bunazosin hydrochloride significantly inhibited glutamate-induced cell death at concentrations of 1 and 10 microM. Cells were also protected when treated with some alpha(1)-adrenoceptor antagonists, but not by the others. Bunazosin hydrochloride showed a high inhibition for Na(+) channels and inhibited the Na(+) influx induced by veratridine or glutamate. These findings indicate that in retinal cultures bunazosin hydrochloride has a neuroprotective effect against glutamate-induced cell death and that the inhibition of Na(+) channels by bunazosin hydrochloride may be partly responsible for this effect.

Effects of poly(ADP-ribose) polymerase inhibitor on NMDA-induced retinal injury.

PURPOSE: Excessive activation of poly(ADP-ribose) polymerase (PARP), a nuclear enzyme that is activated by DNA damage, leads to neuronal cell death through depletion of ATP. The purpose of this study was to determine whether inhibition of PARP has some neuroprotective effects on the N-methyl-D-aspartate (NMDA)-induced functional and morphological injury to the rabbit retina. METHODS: Visually evoked potentials (VEPs) were recorded at different times after an intravitreal injection of NMDA (200, 660, and 2000 nmol) alone, or NMDA with 3-aminobenzamide (ABA, 200 nmol), a PARP inhibitor, or with MK-801 (200 nmol), an NMDA antagonist. The physiological changes were followed for 2 weeks, after which the eyes were enuculeated and prepared for histological examinations. RESULTS: Intravitreal injections of NMDA reduced the amplitudes of rabbit VEPs and the number of cells in the retinal ganglion cell layer in a dose-dependent manner. No significant changes could be detected in the bright-flash electroretinograms (ERGs). Simultaneous injection of MK-801 (200 nmol) significantly diminished the changes induced by intravitreal NMDA. 3-Aminobenzamide (ABA) (200 nmol) also suppressed these changes, but its effects were less than those of MK-801. CONCLUSIONS: NMDA-induced retinal damage can be detected by VEPs, and PARP inhibition has some neuroprotective effects on the NMDA-induced retinal damage.

Adenosine protects cultured retinal neurons against NMDA-induced cell death through A1 receptors.

PURPOSE: To determine whether adenosine can protect cultured retinal neurons, consisting mainly of amacrine cells, from N-methyl-D-aspartate (NMDA)-induced neurotoxicity, and to determine whether agonists and antagonists of adenosine receptors also have a protective effect. METHODS: Cultured retinal neurons obtained from fetal Wistar rats (gestational age 18-19 days) were maintained for 10-11 days. Neurons were exposed to NMDA (1.0 mM) for 10 min with or without adenosine or to NMDA with adenosine receptor agonists or antagonists. Neuronal death was assessed by the trypan-blue exclusion method 24 hr after the exposure. RESULTS: Adenosine at doses of 0.01 microM and higher significantly protected (p < 0.05, Dunnett) primary cultured fetal rat retinal neurons from apoptotic and/or necrotic death induced by NMDA (1.0 mM). The protective effect of adenosine (10 microM) against NMDA-induced neuronal death was lost by simultaneous exposure to selective A1 receptor antagonist but not to A2a receptor antagonist. Selective A1 receptor agonists had similar effects as adenosine, but A2a receptor agonists and 8-Br-cyclic AMP had no effect on cell viability. CONCLUSIONS: Adenosine can protect cultured retinal neurons against NMDA-induced cell death via the A1 receptor.

New fluoroprostaglandin F(2alpha) derivatives with prostanoid FP-receptor agonistic activity as potent ocular-hypotensive agents.

To find new prostanoid FP-receptor agonists possessing potent ocular-hypotensive effects with minimal side effects, we evaluated the agonistic activities of newly synthesized prostaglandin F(2alpha) derivatives for the prostanoid FP-receptor both in vitro and in vivo. The iris constrictions induced by the derivatives and their effects on melanin content were examined using cat isolated iris sphincters and cultured B16 melanoma cells, respectively. The effects of derivative ester forms on miosis and intraocular pressure (IOP) were evaluated in cats and cynomolgus monkeys, respectively. Of these derivatives, 6 out of 12 compounds were more potent iris constrictors, with EC(50) values of 0.6 to 9.4 nM, than a carboxylic acid of latanoprost (EC(50)=13.6 nM). A carboxylic acid of latanoprost (100 microM) significantly increased the melanin content of cultured B16 melanoma cells, but some 15,15-difluoro derivatives, such as AFP-157 and AFP-172, did not. Topically applied AFP-168, AFP-169 and AFP-175 (isopropyl ester, methyl ester and ethyl ester forms, respectively, of AFP-172) induced miosis in cats more potently than latanoprost. AFP-168 (0.0005%) reduced IOP to the same extent as 0.005% latanoprost (for at least 8 h). These findings indicate that 15,15-difluoroprostaglandin F(2alpha) derivatives, especially AFP-168, have more potent prostanoid FP-receptor agonistic activities than latanoprost. Hence, AFP-168 may be worthy of further evaluation as an ocular-hypotensive agent.

Evaluation of nitric oxide synthesis in the optic nerve head in vivo using microdialysis and high-performance liquid chromatography and its interaction with endothelin-1.

PURPOSE: To investigate the relationship between nitric oxide synthesis and endothelin-1 (ET-1) in the optic nerve head in vivo. METHODS: A concentric microdialysis probe was inserted into the optic nerve head of a rabbit and was perfused with Ringer's solution at a constant flow rate of 2 microl/min. The perfused dialysates were collected every 10 min, and levels of nitrite and nitrate in the 10-min dialysate samples were measured after intravitreal injection of ET-1 (100 pmol) using high-performance liquid chromatography based on the Griess method. RESULTS: Basal levels of nitrite and nitrate in the 10-min dialysate were 0.08 +/- 0.01 and 3.95 +/- 0.50 microM, respectively. We confirmed that these levels were reduced by intravenous L-NAME and restored by L-arginine. Intravitreal ET-1 significantly elevated the levels of nitrate to 189% of baseline 10 min after ET-1 application, which was inhibited by pretreatment of intravenous L-NAME (50 mg/kg). CONCLUSION: These results indicate that production of nitric oxide is closely connected with the ET-1 signaling pathway.

Amelioration by topical bunazosin hydrochloride of the impairment in ocular blood flow caused by nitric oxide synthase inhibition in rabbits.

We investigated whether topical instillation of an alpha(1)-adrenergic blocker would improve an insufficient blood supply in the optic nerve head (ONH) and visual function, in rabbits. The effect of systemic NOS inhibition on visual-evoked potentials (VEPs) and hemodynamics in ONH were determined. VEPs were recorded before and every 15 min during a 120-min observation period after an intravenous injection of 50 mg/kg N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor. Capillary blood flow in ONH was evaluated by the laser speckle method throughout the same period. Then, we investigated the effect of topical instillation of a recently developed alpha(1) adrenergic blocker, bunazosin hydrochloride (0.01%), 60 min prior to the intravenous L-NAME (50 mg/kg) on the changes by NOS inhibition. The VEP amplitudes were reduced by L-NAME (10, 20, and 50 mg/kg) in a dose-dependent manner, while the VEP implicit time was unchanged, and no significant changes were detected in the electroretinogram. The reductions in ONH capillary blood flow and VEP amplitudes caused by L-NAME (50 mg/kg) were significantly suppressed by an instillation of bunazosin hydrochloride. These results indicate that blocking alpha(1)-adrenergic receptors may ameliorate the impairments in blood flow and retinal function caused by NOS inhibition. The enhancement of basal vascular tone due to deprivation of continuous NO production may be diminished by this alpha(1)-adrenergic blocker.

Topiramate reduces excitotoxic and ischemic injury in the rat retina.

The effects of topiramate, a drug used clinically as an anti-epileptic, were investigated in excitotoxin-induced neurotoxicity models involving two different retinal primary cultures and in a rat model of retinal ischemic injury. For the in vitro studies, we used retinal-neuron cultures from rat embryos and purified retinal ganglion cells (RGCs) from newborn rats. In the retinal-neuron cultures, neurotoxicity was induced by a 10-min exposure to 1 mM glutamate or (+/-)-a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA). In RGCs, neurotoxicity was induced by incubation for 3 days in a culture medium containing 25 microM glutamate. For the in vivo study, retinal ischemia was induced by elevating intraocular pressure to 130 mmHg for 45 min, and topiramate was administered intraperitoneally before and after the ischemia. Retinal damage was evaluated by measuring the number of cells in the ganglion cell layer (GCL) and the thickness of the inner plexiform layer (IPL), and by examining the a- and b-waves of the electroretinogram (ERG). Topiramate (> or =1 microM) markedly reduced the neuronal cell death induced by each of the excitotoxins in rat retinal-neuron cultures and in RGCs. Ischemia caused a decrease in GCL cells and in IPL thickness, and a diminution of the ERG waves. Histopathologic and functional analyses indicated that systemic treatment with topiramate prevented ischemia-induced damage in a dose-dependent manner. In conclusion, topiramate was protective against excitotoxic and ischemic retinal-neuron damage in vitro and in vivo, respectively. Therefore, it may be useful for treatment of the retina-related diseases such as central retinal artery occlusion, diabetic retinopathy, and glaucoma.

Protective effects of timolol against the neuronal damage induced by glutamate and ischemia in the rat retina.

The purpose of this study was to determine whether timolol, an ocular hypotensive drug, has retinal neuroprotective effects in experimental in vitro and in vivo models. For in vitro studies, we used retinal neuron cultures from rat embryos and purified retinal ganglion cells (RGCs) from newborn rats. In the former, neurotoxicity was induced using 1 mM glutamate and cell viability was assessed. In RGCs, neurotoxicity was induced using 25 microM glutamate for 3 days and cell viability was assessed. For the in vivo study, we used a rat model of retinal ischemic injury induced by elevating intraocular pressure (IOP) by raising the hydrostatic pressure. The retinal damage was evaluated by counting the number of cells in the ganglion cell layer (GCL) and by examining the a- and b-waves in the electroretinogram (ERG). For the intraocular distribution study, 0.5% [3H]timolol was topically applied to rat eyes, and these were enucleated after various intervals and divided into parts. Each part was combusted and the radioactivity measured. Timolol (0.1 and 1 microM) markedly reduced the glutamate-induced neuronal cells in retinal neuron cultures and in RGCs. After ischemic-reperfusion, both the number of cells in the GCL and a- and b-waves in the ERG decreased; however, topically applied 0.5% timolol reduced these effects. Topically applied 0.5% timolol was detected at a concentration of approximately 1 microg/g wet tissue in retina-choroid at 30 min after its application. In conclusion, timolol was effective against retinal neuron damage both in vitro and in vivo. Furthermore, topically applied timolol reached the retina-choroid. These findings suggest that timolol has a direct neuroprotective effect against retinal damage.