Young-Mi Ah

Colistin resistance in Klebsiella pneumoniae

Increasing use of colistin for multidrug-resistant Gram-negative bacterial infections has led to the emergence of colistin resistance in Klebsiella pneumoniae in several countries worldwide, including Europe (especially Greece), and colistin resistance rates are continually increasing. Heteroresistance rates, which were significantly higher than resistance rates, were found to be important. Although the mechanism underlying resistance is unclear, it has been suggested that it is related to lipopolysaccharide modification via diverse routes. Several factors have been reported as being associated with colistin resistance, with improper use and patient-to-patient transmission being most often cited. Total infections and infection-related mortality from colistin-resistant K. pneumoniae are high, but currently there are no established treatment regimens. However, several combination regimens that are mainly colistin-based have been found to be successful for treating such infections.

Low adherence to upfront and extended adjuvant letrozole therapy among early breast cancer patients in a clinical practice setting.

Objective: The aim of this study was to investigate the prevalence and causes of early discontinuation and non-adherence to upfront and extended adjuvant letrozole therapy in breast cancer patients. Methods: Adherence was assessed using medical charts and longitudinal pharmacy records of 609 patients who initiated adjuvant letrozole between January 2002 and April 2011. A Cox proportional hazards regression model was adopted to identify potential predictors of non-adherence. Results: The overall adherence rate after 1 year of therapy was 79.5%, with cumulative rates declining to 63.7% after 3 years and 57.1% after 5 years. A significantly lower rate of adherence in the extended adjuvant group was observed compared with the upfront adjuvant group (49.0 vs. 72.5%, p < 0.001). Adverse events (50.4%) were the major cause of early discontinuation, with musculoskeletal pain (73.2%) being the single most cited reason. Additional factors correlating with non-adherence in the upfront adjuvant group included a delay in initiation of adjuvant hormone therapy, breast-conserving surgery, calcium supplements, bisphosphonate therapy and concomitant medication for co-morbidity. Conclusions: We observed that approximately 57% of patients fully adhered to letrozole therapy over a 5-year treatment period, and that the adherence to extended letrozole was meaningfully lower than the upfront adjuvant letrozole in a clinical practice setting.

Persistence with Antihypertensive Medications in Uncomplicated Treatment-Naïve Patients: Effects of Initial Therapeutic Classes

We aimed to assess one-year persistence with antihypertensive therapy (AHT) among newly treated uncomplicated hypertensive patients in Korea and to evaluate the effect of initial therapeutic classes on persistence. We retrospectively analyzed a random sample of 20% of newly treated uncomplicated hypertensive patients (n = 45,787) in 2012 from the National Health Insurance claims database. This group was classified into six cohorts based on initial AHT class. We then measured treatment persistence, allowing a prescription gap of 60 days. Adherence to AHT was assessed with the medication possession ratio. Calcium channel blockers (CCB, 43.7%) and angiotensin receptor blockers (ARB, 40.3%) were most commonly prescribed as initial monotherapy. Overall, 62.1% and 42.0% were persistent with any AHT and initial class at one year, respectively, and 64.2% were adherent to antihypertensive treatment. Compared with ARBs, the risk of AHT discontinuation was significantly increased with initial use of thiazide diuretics (hazard ratio [HR], 3.16; 95% confidence interval [CI] 2.96-3.74) and beta blockers (HR, 1.86; CI, 1.77-1.95) and was minimally increased with CCBs (HR, 1.12; CI, 1.08-1.15). In conclusion, persistence and adherence to AHT are suboptimal, but the differences are meaningful in persistence and adherence between initial AHT classes.

Antiepileptic drug adherence and persistence in children with epilepsy attending a large tertiary care children's hospital

We aimed to evaluate antiepileptic drug treatment persistence and adherence in paediatric epilepsy patients and investigate the association between medication-taking behaviours and clinical outcome. Medical and prescription records of newly treated paediatric epilepsy patients, aged 1-18 years who initiated antiepileptic drug monotherapy in a tertiary teaching hospital, were retrospectively reviewed. The rates of overall treatment, non-persistence, a treatment gap >60 days, and adherence, as measured by a medication possession ratio ≥0.8, were assessed. The relationship between non-adherence and clinical outcome, defined as an emergency department visit or hospitalisation due to seizure-related reasons, was analysed. A total of 1,172 patients met the inclusion criteria. The proportion of patients who were both persistent and adherent at one year was 70.14% and decreased to 56.83% at two years. Patients who started an antiepileptic drug at one year of age, took older generation antiepileptic drugs as the initial treatment, and those diagnosed with localized seizures were less likely to be adherent to and persistent with overall antiepileptic drug treatment. Patients who were non-adherent to antiepileptic drug treatment were at an increased risk of hospitalisation or emergency department visits for seizure-related reasons (adjusted HR 2.10, 95% CI 1.25-3.55). This large population study shows that 70% of paediatric epilepsy patients were persistent with and adherent to antiepileptic drugs after one year of treatment and confirms that non-adherence to antiepileptic drug treatment is an important factor in seizure-related clinical outcome.

Influence of initial angiotensin receptor blockers on treatment persistence in uncomplicated hypertension: A nation-wide population-based study

ABSTRACT We identified 55 504 uncomplicated, treatment-naïve hypertensive patients who started angiotensin II receptor blockers (ARBs) in 2012 from national claims data. The proportion of patients remaining on any hypertension treatment at 12 months and the adherence rate were similar between the losartan cohort (66.82% and 68.25%) and the nonlosartan ARB cohort (67.48% and 69.01%). After adjusting for confounding factors, there was no difference in persistence (aHR 0.98, 95% confidence interval (CI) 0.95–1.01) on hypertension treatment between losartan and nonlosartan ARB cohort. Post hoc analysis showed that patients initially prescribed eprosartan, irbesartan (both, aHR 1.33), and telmisartan (aHR 1.11) were more likely to discontinue the initial drug, whereas valsartan initiators (aHR 0.96) were less likely compared with losartan initiators.

Evaluation of Concordance Among Different Drug Information Sources Regarding the Recommendations for Dosage Adjustment in Renal Impairment

Background: It is very important to prescribe appropriate drugs and adjust medication and dosage for optimal disease management not only to maximize patient outcomes, but also to minimize adverse events. So, the accuracy of drug information and consistency among different resources would have a significant effect on drug therapy. Objectives: We aimed to evaluate the concordance among five drug information sources regarding the recommendations for dosage adjustment in renal impairment. Methods: The five drug information resources were selected the Korean National Formulary Drug (KNF), the British national formula 2013 (BNF 65), Daily Med in USA, Lexicomp-online, and Drug Prescribing in Renal Failure (DPRF, 5th ed.). After having classified the degrees of renal function and defined the terms used for the dosing methods, we analyzed the concordance in dosing recommendations in renal deficiency among the information sources by calculating Fleiss Kappa. Results: In the dosing adjustments of patients with renal insufficiency, there were some cases of contraindicated drugs that were not matched in each reference. Statistical analysis of the concordance of four references, except DPRF, and evaluation of 168 of the drugs that were mentioned in all four sources showed the Fleiss Kappa coefficientto be 0.243. This indicatesfair agreement among the data. Conclusion: Fair agreement was observed among 4 sources. This may be owing to discrepancies in the frequency of updating drug information sources. We suggest that the quantitative standard be used to classify renal function and to maintain consistency in definition of renal impairment.