Effects of a pharmacist-managed anticoagulation outpatient clinic in Taiwan: evaluation of patient knowledge, satisfaction, and clinical outcomes.

Objective: The study aimed to evaluate the improvement of patient knowledge of warfarin use, satisfaction with pharmacists, and the quality of international normalized ratio (INR) control after the implementation of an anticoagulant clinic (ACC) service.Methods: This was a prospective single-group pre- and post-comparison study. Patients who were at least 20 years of age and participated in a pharmacist-managed ACC service were enrolled from February 2012 to September 2015. Each participant completed a self-administered questionnaire before and after the ACC service to evaluate changes in warfarin knowledge. Another questionnaire was distributed after the ACC to evaluate participants' satisfaction with the pharmacist service in the ACC. The INR levels before and after the ACC intervention were obtained to calculate the proportion of time spent in the therapeutic INR range (time in therapeutic range, TTR). Paired t-tests were used to compare changes in participants' knowledge related to warfarin use. Multiple linear regressions were performed to explore the predictors associated with the participants' knowledge scores and TTR after the ACC intervention.Results: One hundred and forty-eight participants were enrolled in this study. A significant improvement (31.5%,p<0.001) in the knowledge of warfarin use was observed at the end of the ACC intervention. The interaction between warfarin and food was the most confusing factor for participants in warfarin use. More than 95% of the participants perceived a positive value of the pharmacist-managed ACC service. However, the consultation fee was the least satisfactory of the ACC service. The average TTR increased from 51.0±34.3% to 78.6±24.5% (p<0.001) after the ACC service was implemented. Participants' education levels and baseline knowledge scores were significant determinants associated with the knowledge improvement in the appropriate warfarin use (p<0.001).Conclusions: A pharmacist-managed ACC improved patient knowledge of warfarin use and INR control, and led to high satisfaction with the pharmacist service in the ACC in Taiwan. Pharmacists should focus on patients with lower education levels to facilitate their understanding of the appropriate warfarin use for better health outcomes.

Pharmacokinetics and dosing of vancomycin in patients undergoing sustained low efficiency daily diafiltration (SLEDD-f): A prospective study.

BACKGROUND/PURPOSE: The pharmacokinetics of vancomycin in patients who undergo sustained low efficiency daily diafiltration (SLEDD-f) is not clear. This study aimed to determine the appropriate vancomycin dosage regimen for patients receiving SLEDD-f. METHODS: This prospectively observational study enrolled critically ill patients older than 18 years old that used SLEDD-f as renal replacement therapy and received vancomycin treatment. An 8-h SLEDD-f was performed with FX-60 (high-flux helixone membrane, 1.4 m2). Serial blood samples were collected before, during, and after SLEDD-f to analyse vancomycin serum concentrations. Effluent fluid samples (a mixture of dialysate and ultrafiltrate) were also collected to determine the amount of vancomycin removal. RESULTS: Seventeen patients were enrolled, and 10 completed the study. The amount of vancomycin removal was 447.4 ± 88.8 mg (about 78.4 ± 18.4% of the dose administered before SLEDD-f). The vancomycin concentration was reduced by 57.5 ± 14.9% during SLEDD-f, and this reduction was followed by a rebound with duration of one to three hours. The elimination half-life of vancomycin decreased from 64.1 ± 35.7 h before SLEDD-f to 7.0 ± 3.0 h during SLEDD-f. CONCLUSION: Significant amount of vancomycin removed during SLEDD-f. Despite the existence of post-dialysis rebound, a sufficient supplemental dose is necessary to maintain therapeutic range.

Prognostic factors in epithelial ovarian cancer: A population-based study.

The overall survival (OS) of patients with ovarian cancer is poor while epithelial ovarian cancer (EOC) is the most lethal gynecologic cancer. The aim of the present study was to evaluate the clinico-pathologic characteristics, especially the prognostic factors, for patients with epithelial ovarian cancer (EOC) in Taiwan. Information about newly diagnosed patients with EOC from 2009 to 2012 was retrieved from the database of the Taiwan Cancer Registry. Data from 2009 to 2013 for the respective cases from the claims database of Taiwan's National Health Insurance and National Death Registry were then retrieved. Potential prognostic factors were analyzed. The mean age at diagnosis of the 2,498 patients was 52.8 years. Serous carcinoma and clear cell carcinoma were diagnosed in 43.3% and 22.8% of the total patients, respectively. For patients with early-stage disease, taxane-based adjuvant chemotherapy, stage I, and younger age at diagnosis led to better overall survival (p = 0.030, p = 0.002, p<0.001, respectively) in multivariable analysis. For advanced-stage patients, histology (endometrioid type), taxane-based adjuvant chemotherapy, stage, and age at diagnosis had a significant impact on OS (p<0.001, p = 0.020, p<0.001, p<0.001, respectively). In conclusion, taxane-based chemotherapy impacts the outcome of patients with EOC. Personalized medicine may be needed for different histological types of EOC because of their different outcomes.

Age- and gender-specific epidemiology, treatment patterns, and economic burden of osteoporosis and associated fracture in Taiwan between 2009 and 2013.

This nationwide study investigated the epidemiology, treatment patterns, and economic burden of osteoporosis and associated fracture in Taiwan. The treatment of osteoporosis is alarmingly suboptimal, considering the significantly increased economic burden of major osteoporotic fracture. Osteoporosis men received lesser anti-osteoporosis drugs but had higher incremental costs attributable to osteoporotic fractures. PURPOSE: This nationwide study investigated the epidemiology, treatment patterns, and economic burden of osteoporosis and associated fracture between 2009 and 2013 in Taiwan. METHODS: We used the National Health Insurance Research Database as our data source. The prevalence of diagnosed osteoporosis and major osteoporotic fractures was calculated annually from 2009 to 2013, stratified by age and gender. Osteoporosis patients who received any prescription of anti-osteoporosis drugs during each fiscal year were defined as osteoporosis patients under treatment. Healthcare utilization and associated direct medical costs were used to quantify the economic burden of osteoporosis. For patients who encountered major osteoporotic fracture, the incremental changes of direct medical costs attributable to fracture using a pre- and post-quasi-experimental design were estimated. Furthermore, we compared the annual direct medical costs of patients who encountered major osteoporotic fracture with those diagnosed osteoporosis only and with the general population. RESULTS: The prevalence of diagnosed osteoporosis increased with age, with the highest rate among those aged 80 and older. Overall, less than one-third of women and only 10% of men received anti-osteoporosis drugs among osteoporosis patients. The annual direct medical costs for osteoporosis patients increased steadily from 2009 to 2013. The total medical costs and incremental change of direct medical costs were higher in men than those in women. CONCLUSION: We found the treatment of osteoporosis to be alarmingly suboptimal, considering the significantly increased economic burden of major osteoporotic fracture also identified in this study. Osteoporosis men received lesser anti-osteoporosis drugs but had higher incremental costs attributable to major osteoporotic fractures.

Bisphosphonate Use and the Risk of Undergoing Total Knee Arthroplasty in Osteoporotic Patients with Osteoarthritis: A Nationwide Cohort Study in Taiwan.

BACKGROUND: The use of bisphosphonates has been reported to have potential beneficial effects on knee osteoarthritis, but existing studies have limitations. The purpose of this study was to examine the association of bisphosphonate use with the risk of undergoing total knee arthroplasty and with the consumption of pain medication among osteoporotic patients with knee osteoarthritis. METHODS: We identified patients who were newly diagnosed with knee osteoarthritis among a cohort of patients with osteoporosis from 2009 to 2012 in the National Health Insurance Research Database in Taiwan. We further categorized these patients into 2 groups: those who were treated with bisphosphonates (bisphosphonate users) and those who were not treated with any anti-osteoporosis drug (nonusers). Bisphosphonate treatment adherence was calculated by the medication possession ratio (MPR) as the proportion of days of bisphosphonate treatment within a fixed duration; an MPR of ≥80% was considered high adherence. The primary and secondary outcomes of interest were undergoing total knee arthroplasty and the use of pain medication, respectively. Analyses using Cox proportional hazard models with propensity-score adjustment were performed to estimate the association between bisphosphonate use and the risk of undergoing total knee arthroplasty. The incremental change in the mean accumulated defined daily doses of pain medications among both bisphosphonate users and nonusers was calculated. RESULTS: We identified 16,276 bisphosphonate users and 123,791 nonusers of any anti-osteoporosis drug among the patients with osteoporosis who were newly diagnosed with osteoarthritis. Bisphosphonate use was significantly associated with a decreased risk of total knee arthroplasty (adjusted hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.69 to 0.83; p < 0.001). In patients with a follow-up period of ≥24 months and an MPR of ≥80%, the effect size was significantly greater (adjusted HR, 0.66; p = 0.048). Over the 5 years of follow-up, we found a significantly greater decrease in the use of pain medication among bisphosphonate users than among nonusers (p < 0.001; Chow test). CONCLUSIONS: Among patients with osteoporosis and osteoarthritis, bisphosphonate use was associated with a significantly lower risk of total knee arthroplasty, especially in patients with high adherence and longer treatment duration. A lower consumption of pain medication was also found for bisphosphonate users among the patients with osteoporosis and osteoarthritis. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Factors driving the use of warfarin and non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation.

BACKGROUND/PURPOSE: In the past, warfarin was the drug of choice for stroke prevention in patients with atrial fibrillation (AF). Recently, non-vitamin K antagonist oral anticoagulants (NOACs) have been approved as an alternative to warfarin in nonvalvular AF. However, there is a limited amount of real-world data on how NOACs are currently being used in Taiwan. This study was conducted to investigate the factors driving the initiation of anticoagulants and the selection of different anticoagulants in patients with AF. METHODS: We used National Taiwan University Hospital's electronic database to identify all nonvalvular AF patients from January 1, 2007 to December 31, 2013. Multivariate logistic regression models were used to examine the factors driving the initiation of anticoagulants and the selection of different anticoagulants. RESULTS: Among AF patients, 66.4% of anticoagulants users used NOACs instead of warfarin after the era of NOACs. Patients with female sex, hypertension, ischemic heart disease, cancer, hepatic disease, renal disease, bleeding history, and aspirin use were less likely to be anticoagulant users but are more likely to be anticoagulant users with a history of stroke (odds ratio = 2.64; 95% confidence interval, 2.02-3.45). Older age, ischemic heart disease, and aspirin use were the factors associated with NOACs usage, whereas hepatic disease showed the opposite results (odds ratio = 0.09; 95% confidence interval, 0.02-0.42). CONCLUSION: Stroke history was associated with anticoagulant use, whereas comorbidities associated with increased risk of bleeding showed the opposite result. Patients with hepatic disease were less likely to use NOACs.

Use of Hypoprothrombinemia-Inducing Cephalosporins and the Risk of Hemorrhagic Events: A Nationwide Nested Case-Control Study.

OBJECTIVE: Existing data regarding the risk of hemorrhagic events associated with exposure to hypoprothrombinemia-inducing cephalosporins are limited by the small sample size. This population-based study aimed to examine the association between exposure to hypoprothrombinemia-inducing cephalosporins and hemorrhagic events using National Health Insurance Research Database in Taiwan. DESIGN: A nationwide nested case-control study. SETTING: National Health Insurance Research database. PARTICIPANTS: We conducted a nested case-control study within a cohort of 6191 patients who received hypoprothrombinemia-inducing cephalosporins and other antibiotics for more than 48 hours. Multivariable conditional logistic regressions were used to calculate the adjusted odds ratio (aOR) and 95% confidence interval (CI) for hemorrhagic events associated with exposure to hypoprothrombinemia-inducing cephalosporins (overall, cumulative dose measured as defined daily dose (DDD), and individual cephalosporins). RESULTS: Within the cohort, we identified 704 patients with hemorrhagic events and 2816 matched controls. Use of hypoprothrombinemia-inducing cephalosporins was associated with increased risk of hemorrhagic events (aOR, 1.71; 95% CI, 1.42-2.06), which increased with higher cumulative doses (<3 DDDs, aOR 1.62; 3-5 DDDs, aOR 1.78; and >5 DDDs, aOR 1.89). The aOR for individual cephalosporin was 2.88 (95% CI, 2.08-4.00), 1.35 (1.09-1.67) and 4.57 (2.63-7.95) for cefmetazole, flomoxef, and cefoperazone, respectively. Other risk factors included use of anticoagulants (aOR 2.08 [95% CI, 1.64-2.63]), liver failure (aOR 1.69 [1.30-2.18]), poor nutritional status (aOR 1.41 [1.15-1.73]), and history of hemorrhagic events (aOR 2.57 [1.94-3.41]) 6 months prior to the index date. CONCLUSIONS: Use of hypoprothrombinemia-inducing cephalosporins increases risk of hemorrhagic events. Close watch for hemorrhagic events is recommended when prescribing these cephalosporins, especially in patients who are at higher risk.

The Effect of Different Carbapenem Antibiotics (Ertapenem, Imipenem/Cilastatin, and Meropenem) on Serum Valproic Acid Concentrations.

BACKGROUND: Carbapenem antibiotics (CBPMs) may significantly reduce the serum concentration of valproic acid (VPA), but the extent of this effect among various CBPMs is unknown. This study compared the extent and onset of the interactions among ertapenem, imipenem/cilastatin, and meropenem. METHODS: A 5-year retrospective study was performed. Hospitalized patients over 18 years old who received VPA and a CBPM concurrently were enrolled via the pharmacy computer system. Patients who lacked VPA serum concentration measurements before or during CBPMs' use, had concurrent medication(s) that might interfere with VPA metabolism, or had a history of liver cirrhosis were excluded. Total VPA serum concentrations before and during CBPMs' use and after its discontinuation were recorded, and differences among various CBPMs were analyzed. RESULTS: Fifty-two patients were included in this analysis. Irrespective of the route of administration, VPA serum concentrations were subtherapeutic in 90% of the subjects during CBPMs' use. There was a significant decrease (P < 0.001) in VPA serum concentrations during the use of CBPMs: 72% ± 17%, 42% ± 22%, and 67% ± 19% in the ertapenem (N = 9), imipenem/cilastatin (N = 17), and meropenem (N = 26) groups, respectively. The effect of ertapenem and meropenem on VPA was significantly more expressed than that of imipenem/cilastatin (P < 0.005). The onset of this drug interaction occurred within 24 hours of CBPMs' administration, and VPA serum concentrations returned to 90% of baseline within 7 days of CBPMs' discontinuation along with a 20% increase in VPA dose. Increasing VPA dose during the use of ertapenem or meropenem did not result in elevating VPA serum concentrations to therapeutic levels during the combined therapy period. CONCLUSIONS: CBPMs reduced VPA serum concentration within 24 hours of administration by approximately 60%. Ertapenem and meropenem had a greater effect on VPA serum concentration than imipenem/cilastatin. Because of the dramatic reduction of VPA serum concentration during CBPMs' use, concomitant use of VPA and CBPMs should be avoided.

Risk factors of ifosfamide-related encephalopathy in adult patients with cancer: A retrospective analysis.

BACKGROUND/PURPOSE: Ifosfamide, a widely used chemotherapeutic agent, has been frequently associated with encephalopathy. A larger-scale study was conducted to identify risk factors of ifosfamide-related encephalopathy, including hepatic function. METHODS: Adult patients who had completed at least one cycle of ifosfamide between January 2008 and December 2010 were included. Those with renal failure or liver failure were excluded. Data were collected through chart review. Patients with encephalopathy and patients without encephalopathy were compared on age, Eastern Cooperative Oncology Group (ECOG) performance status (PS), baseline serum creatinine (SCr) level, albumin level, white blood cell count, liver function, brain metastasis, and dosage of ifosfamide. Chi-square test or Fisher's exact test, Student t test, and univariate and multivariate logistic regressions were used for analysis. RESULTS: This study enrolled 337 patients. Thirty-eight patients (11%) had ifosfamide-related encephalopathy. They had poorer ECOG PS; higher SCr level, white blood cell count, and aspartate aminotransferase level; and lower serum albumin level compared with patients without encephalopathy. Ifosfamide dosage, brain metastasis, and age were not significant risk factors. Multivariate analysis indicated that only ECOG PS, SCr level, and albumin level contributed significantly to the risk. CONCLUSION: To date, this is the largest-scale study to have analyzed the risk factors of ifosfamide-related encephalopathy. This study confirms that an ECOG PS of 2-4 and increased SCr level are significant risk factors of ifosfamide-related encephalopathy, whereas increased albumin level decreases the risk, consistent with previous reports. Higher aspartate aminotransferase levels have no significant impact. In contrast to previous studies, ifosfamide dosage and brain metastasis are not significant contributing factors.

Pharmacokinetics of vancomycin in adults receiving extracorporeal membrane oxygenation.

BACKGROUND/PURPOSE: Extracorporeal membrane oxygenation (ECMO) alters the pharmacokinetics (PK) of vancomycin in neonates; but data on adults is limited. METHODS: This is a prospective, matched cohort, single center, pharmacokinetic study. For each adult patient who received vancomycin therapy in the ECMO group (with either centrifugal pump or roller pump), a control patient was matched by age (≥ 60 years or < 60 years), gender, and creatinine clearance (CLCr) in intensive care units. After vancomycin was administered for at least four doses, serial blood samples were drawn at 0.5 hours, 1 hour, 2 hours, 3 hours, 5 hours, 7 hours, 11 hours, 23 hours, 35 hours, and 47 hours post vancomycin infusion according to the dosing intervals. The serum concentration-time profile was fitted to a noncompartment model and a nonlinear mixed effect model to determine the PK parameters. RESULTS: Twenty-two critically ill adults without renal replacement therapy were enrolled. There were no significant differences between the ECMO group and the matched group in demographics, renal function, and PK parameters. However, vancomycin clearance in the roller pump group was significantly lower than that in the matched control (0.83 ± 0.43 mL/min/kg vs. 0.97 ± 0.43 mL/min/kg, p = 0.002). CONCLUSION: Vancomycin clearance in patients receiving ECMO with a roller pump was significantly lower than that in the matched cohort. Vancomycin PK parameters in patients on ECMO with a centrifugal pump were comparable to those in the matched control group.

Incidence and Risk Factors for Acute Kidney Injury Following Mannitol Infusion in Patients With Acute Stroke: A Retrospective Cohort Study.

Mannitol, an osmotic diuretic, is commonly used to treat patients with acute brain edema, but its use also increases the risk of developing acute kidney injury (AKI). In this study, we investigated the incidence and risk factors of mannitol-related AKI in acute stroke patients.A total of 432 patients (ischemic stroke 62.3%) >20 years of age who were admitted to the neurocritical care center in a tertiary hospital and received mannitol treatment were enrolled in this study. Clinical parameters including the scores of National Institutes of Health Stroke Scale (NIHSS) at admission, vascular risk factors, laboratory data, and concurrent nephrotoxic medications were registered. Acute kidney injury was defined as an absolute elevation in the serum creatinine (Scr) level of ≥0.3 mg/dL from the baseline or a ≥50% increase in Scr.The incidence of mannitol-related AKI was 6.5% (95% confidence interval, 4.5%-9.3%) in acute stroke patients, 6.3% in patients with ischemic stroke, and 6.7% in patients with intracerebral hemorrhage. Multivariate analysis revealed that diabetes, lower estimated glomerular filtration rate at baseline, higher initial NIHSS score, and concurrent use of diuretics increased the risk of mannitol-related AKI. When present, the combination of these elements displayed an area under the receiver operating characteristic curve of 0.839 (95% confidence interval, 0.770-0.909). In conclusion, mannitol-related AKI is not uncommon in the treatment of acute stroke patients, especially in those with vulnerable risk factors.

Nephrotoxic Polypharmacy and Risk of Contrast Medium-Induced Nephropathy in Hospitalized Patients Undergoing Contrast-Enhanced CT.

OBJECTIVE: For unknown reasons, there is discordance among previous reports with regard to the association of contrast medium (CM) with nephropathy and the incidence of nephropathy after contrast-enhanced CT. This study aimed to determine the frequency of and possible factors related to CM-induced nephropathy in hospitalized patients, with an emphasis on detailing coprescriptions with nephrotoxic potential. MATERIALS AND METHODS: Of 1378 inpatients who underwent CT, 208 (15.1%) met the inclusion criteria: receipt of IV iodinated CM and baseline serum creatinine level obtained within 45 days before and within 2 weeks after CT. Patient demographics, clinical characteristics, comorbidity, nephrotoxic comedications (nine classes of drugs), and type of CM administered were retrospectively reviewed. Relationships between CM-induced nephropathy (serum creatinine level increase ≥ 25% or ≥ 0.5 mg/dL after CT) and risk factors were assessed by stepwise multivariate logistic regression. RESULTS: The cohort of 208 subjects had a high number of comorbidities (mean [± SD], 5.8 ± 3.5 diagnoses) and a high rate of receiving nephrotoxic comedications (45.2%). CM-induced nephropathy was detected in 27 (13.0%) patients. Concurrent use of four nephrotoxic agents (odds ratio [OR], 26.250; 95% CI, 3.673-233.993) was the most influential factor associated with CM-induced nephropathy; other predictors included preexisting renal disease (OR, 8.218; 95% CI, 1.622-42.357), baseline serum creatinine level less than 0.7 or greater than or equal to 1.3 mg/dL (OR, 3.463; 95% CI, 1.341-9.025), and hemoglobin level less than 9.3 g/dL (OR, 3.141; 95% CI, 1.087-8.946). CONCLUSION: Among the known risk factors, such as preexisting renal disease, high serum creatinine level, and low hemoglobin level, a statistically significant association was identified between CM-induced nephropathy and concurrent receipt of four nephrotoxic medications. Relevant preventive measures are warranted for individuals at risk, especially hospitalized patients receiving multiple nephrotoxic medications who require contrast-enhanced CT.

De novo cancer avoidance after renal transplantation: A case-control study on low-dose sirolimus combined with a calcineurin inhibitor.

BACKGROUND/PURPOSE: Full-dose sirolimus (SRL) therapy without a calcineurin inhibitor (CNI) reduces the incidence of malignancy after renal transplantation, but with significant side effects. We hypothesized that de novo therapy with low-dose SRL combined with a CNI could still prevent cancer in renal transplant recipients. METHODS: A retrospective case-control study was performed to assess the cancer incidence among renal transplant patients who had undergone surgery in our transplant centers between January 2000 and June 2012. Patients who received low-dose SRL and a CNI (SRL group, n = 189) were compared with patients receiving conventional CNI-based therapy in the same hospitals (Conventional group, n = 271). RESULTS: The 5-year graft and patient survival rates were comparable between the two groups. Seven patients in the SRL group and 24 patients in the Conventional group developed malignancies during mean follow-up periods of 68.2 ± 37.5 months and 81.7 ± 51.4 months, respectively. The cancer incidence at 5 years was significantly lower in the SRL group (1.9%), than that in the Conventional group (6.7%; p = 0.04). By multivariate analyses, SRL therapy (p = 0.04), male sex (p = 0.04), and younger age (p = 0.01) were significantly associated with a lower risk of malignancy after kidney transplantation. CONCLUSION: De novo therapy with low-dose SRL combined with a CNI was associated with reduced risk of post-transplant cancer in renal transplant recipients. De novo cancer prevention using a low-dose proliferation signal inhibitor such as SRL could be effective for renal transplant recipients.

Medication knowledge to be improved in participants in community universities in Taiwan: Outcome of a nationwide community university program.

BACKGROUND/PURPOSE: To assess knowledge improvement by the participants in a pharmacist-facilitated national community education program over a 4-month semester and to identify the educational needs of adults related to medications. METHODS: This was a single-group, pre- and post-program comparative study. From February 2005 to February 2006, 1983 community residents participating in the education program implemented at 57 community universities nationwide were included. A questionnaire consisting of 50 true/false questions was administered before and after the program to assess the participants' medication knowledge. Paired t test was used to analyze the pre- and post-program differences and generalized linear mixed models were applied to examine the demographic variables that might influence the background knowledge and outcome after adjusting for school effects. RESULTS: A total of 848 participants (42.8%) completed the pre-to-post questionnaire. Baseline medication knowledge was positively correlated with participants' education level and negatively correlated with age. Significant improvement (11.3%, p < 0.001) in medication knowledge was evident at the end of the program. The age and education level were significant determinants in the improvement of the pre-to-post program test score. The specific areas that required improvement most in the knowledge of the participants were: instructions on refill prescriptions, proper storage of medication, the health insurance system, drug use in special populations, and over-the-counter drugs. CONCLUSION: This national program improved participants' medication knowledge over a 4-month period. Patient counseling focusing more on the knowledge deficiency identified in this study during patient care is recommended.

Formulation and stability of an extemporaneous 0.02% chlorhexidine digluconate ophthalmic solution.

BACKGROUND/PURPOSE: Acanthamoeba keratitis is difficult to treat because Acanthamoeba cysts are resistant to the majority of antimicrobial agents. Despite the efficacy of 0.02% chlorhexidine in treating Acanthamoeba keratitis, a lack of data in the literature regarding the formulation's stability limits its clinical use. The objective of this study was to develop an optimal extemporaneous 0.02% chlorhexidine digluconate ophthalmic formulation for patients in need. METHODS: With available active pharmaceutical ingredients, 0.02% chlorhexidine digluconate sample solutions were prepared by diluting with BSS Plus Solution or acetate buffer. Influences of the buffer, type of container, and temperature under daily-open condition were assessed based on the changes of pH values and chlorhexidine concentrations of the test samples weekly. To determine the beyond-use date, the optimal samples were stored at 2-8°C or room temperature, and analyzed at time 0 and at Week 1, Week 2, Week 3, Week 4, Week 5, Week 8, Week 12, and Week 24. RESULTS: Despite chlorhexidine exhibiting better stability in acetate buffer than in BSS solution, its shelf-life was < 14 days when stored in a light-resistant low-density polyethylene container. The acetate-buffered 0.02% chlorhexidine digluconate solution stored in light-resistant high-density polyethylene eyedroppers did not exhibit significant changes in pH or strength at any time interval. CONCLUSION: The acetate-buffered 0.02% chlorhexidine digluconate ophthalmic solution stored in light-resistant high-density polyethylene eyedroppers demonstrated excellent stability at 2-25°C for 6 months after being sealed and for 1 month after opening. This finding will enable us to prepare 0.02% chlorhexidine digluconate ophthalmic solutions based on a doctor's prescription.

Depletion of arginine by recombinant arginine deiminase induces nNOS-activated neurotoxicity in neuroblastoma cells.

The abnormal regulation of inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS) is associated with neurodegenerative disorders. Recombinant arginine deiminase (rADI) is a selective NO modulator of iNOS and eNOS in endothelial cells, and it also exhibits neuroprotective activity in an iNOS-induced neuron-microglia coculture system. However, the effect of rADI on nNOS remains unknown. Addressing this issue is important for evaluating the potential application of rADI in neurodegenerative diseases. SH-SY5Y cells were treated with N-methyl-D-aspartic acid (NMDA) to activate nNOS. NMDA increased NO production by 39.7 ± 3.9% via nNOS under arginine-containing conditions, but there was no significant increase in both arginine-free and rADI pretreated arginine-containing (citrulline) buffer. Subsequently, neither NMDA nor rADI alone caused cytotoxicity, whereas cotreatment with NMDA and rADI resulted in dissipation of the cell mitochondrial membrane potential and decreased cell viability. The mechanism of rADI cytotoxicity in the presence of NMDA is caused by the inhibition of NO production via nNOS mediated by the NMDA receptor, which was abolished when extracellular arginine was absent, even in the presence of citrulline. rADI not only reduced NO production but also caused cellular toxicity in nNOS-activated SH-SY5Y cells, suggesting a dual role for rADI in NOS-mediated neurotoxicity.

Intracellular delivery of recombinant arginine deiminase (rADI) by heparin-binding hemagglutinin adhesion peptide restores sensitivity in rADI-resistant cancer cells.

Recombinant arginine deiminase (rADI) has been used in clinical trials for arginine-auxotrophic cancers. However, the emergence of rADI resistance, due to the overexpression of argininosuccinate synthetase (AS), has introduced an obstacle in its clinical application. Here, we have proposed a strategy for the intracellular delivery of rADI, which depletes both extracellular and intracellular arginine, to restore the sensitivity of rADI-resistant cancer cells. In this study, the C terminus of heparin-binding hemagglutinin adhesion protein from Mycobacterium tuberculosis (HBHAc), which contains 23 amino acids, was used to deliver rADI into rADI-resistant human breast adenocarcinoma cells (MCF-7). Chemical conjugates (l- and d-HBHAc-SPDP-rADI) and a recombinant fusion protein (rHBHAc-ADI) were produced. l- and d-HBHAc-SPDP-rADI showed a significantly higher cellular uptake of rADI by MCF-7 cells compared to that of rADI alone. Cell viability was significantly decreased in a dose-dependent manner in response to l- and d-HBHAc-SPDP-rADI treatments. In addition, the ratio of intracellular concentration of citrulline to arginine in cells treated with l- and d-HBHAc-SPDP-rADI was significantly increased by 1.4- and 1.7-fold, respectively, compared with that obtained in cells treated with rADI alone (p < 0.001). Similar results were obtained with the recombinant fusion protein rHBHAc-ADI. Our study demonstrates that the increased cellular uptake of rADI by HBHAc modification can restore the sensitivity of rADI treatment in MCF-7 cells. rHBHAc-ADI may represent a novel class of antitumor enzyme with an intracellular mechanism that is independent of AS expression.

Statins and the risk of liver injury: a population-based case-control study.

OBJECTIVE: This case-control study investigated the association between statin use and liver injury using Taiwan's National Health Insurance Research Database. METHODS: Our study subjects included 4165 cases (patients who had been admitted with a primary diagnosis of liver injury between 2002 and 2009) and 16 660 age-matched, sex-matched and index date-matched controls. Multivariable conditional regression models were used to estimate the association between statin use and liver injury. RESULTS: Users of statins were not associated with risk of liver injury (adjusted odds ratio [aOR] 1.04; 95% confidence interval [0.90-1.19]) when compared with nonusers. Nevertheless, a higher dose of statin (≥1 defined daily dose; aOR 1.55 [1.14-2.11]) and use of rosuvastatin before event of liver injury (aOR 1.38 [1.03-1.85]) were significantly associated with liver injury. CONCLUSIONS: This population-based study extends previous evidence by exploring the potential association between statins use and risk of liver injury. Overall, we found that statin was not associated with risk of liver injury. Nevertheless, special concern should be paid to those who used statin ≥1 defined daily dose and rosuvastatin.

Intracellular delivery of cytochrome c by galactosylated albumin to hepatocarcinoma cells.

In some cancer cells, translocation of cytochrome c (Cyt c) from mitochondria to the cytoplasma is inhibited. This inhibition prevents cells from undergoing apoptotic cell death and can lead to uncontrolled cell growth. Increasing cytoplasmic concentration of Cyt c can induce apoptosis in cancer cells as a strategy of cancer therapy. Here we proposed a galactosylated albumin based carrier for intracellular delivery of Cyt c to hepatocarcinoma cells. Galactosylated albumin is recognized by highly expressed asialoglycoprotein receptors (ASGPR) on hepatocarcinoma cells and is further internalized into cells via receptor mediated endocytosis. Cyt c was chemically conjugated to galactosylated albumin with a reducible disulfide linker in order to release Cyt c from the carrier inside cells. We tested cellular uptake and cytotoxicity of Cyt c conjugates in ASGPR positive and negative hepatocarcinoma cells. The results showed galatosylated albumin significantly increased cellular uptake in both cell types resulting in cytotoxicity in a dose dependent manner through the induction of apoptosis. The lack of ASGPR specific uptake might be due to other carbohydrate-recognizing receptors expressed on tumor cells. In general, our work has shown that intracellular delivery of Cyt c to tumor cells can be an alternative therapeutic approach and galactosylated albumin can be a protein drug carrier for intracellular delivery.