Experiential education is a core curriculum of pharmacy education. In experiential education, formative feedback is an integral component of learning and teaching process. Feedback is defined as information provided by a preceptor regarding student's performance based on direct observation. With effective feedback, students can have opportunities to reinforce or correct behaviors and to acquire knowledge or skills. Students highly value and appreciate feedback. They rank provision of effective feedback as one of the most important qualities of preceptors. Preceptors, however, lack an understanding of feedback or practical skills necessary for providing effective feedback. As a result in reality, the feedback provided to students can be differentially effective in improving students' learning. This article describes a theoretical understanding of feedback including definition and value, as well as types of feedback. In addition, practical aspects in providing feedback, such as contents, timing, techniques, and models, are addressed. By understanding the value of feedback and mastering various feedback skills, preceptors will promote students' learning and enhance educational outcomes of experiential education.

Neonates have large inter-individual variability in pharmacokinetic parameters of many drugs due to developmental differences. The aim of this study was to investigate the factors affecting the pharmacokinetic parameters of drugs, which are commonly used in critically ill neonates. Factors that reflect physiologic maturation such as gestational age, postnatal age, postconceptional age, birth weight, and current body weight were correlated with pharmacokinetic parameters in neonates, especially preterm infants. Comorbidity characteristics affecting pharmacokinetics in critically ill neonates were perinatal asphyxia, hypoxic ischemic encephalopathy, patent ductus arteriosus (PDA), and renal dysfunction. Administration of indomethacin or ibuprofen in neonates with PDA was associated with the reduced clearance of renally excreted drugs such as vancomycin and amikacin. Therapeutic hypothermia and extracoporeal membrane oxygenation were influencing factors on pharmacokinetic parameters in critically ill neonates. Dosing adjustment and careful monitoring according to the factors affecting pharmacokinetic variability is required for safe and effective pharmacotherapy in neonatal intensive care unit.

Objective: This study was conducted to assess the current status of experiential education, by analyzing pharmacy students' satisfaction and evaluation for practice sites and preceptors for 3 years from 2014 through 2016. Methods: Students evaluated the practice sites and preceptors using a 5-point and a 4-point Likert scale, respectively. Analysis was performed based on the types of curriculums and practice sites. In addition, sub-analysis was conducted based on the types of health-system pharmacy and the community pharmacy. Results: Total 203 students responded to the survey questionnaires. The 3-year average score of students' satisfaction with practice sites was 4.25. In the sub-analysis conducted based on the types of health-system pharmacy, the score was higher in the tertiary hospital pharmacies than that of the general hospital pharmacies (4.49 vs. 4.06, P<0.001). For community pharmacy, the difference in the score of the 3-year analysis was not significant, depending on the types (4.51 vs. 4.33, P=0.054). The average score of students' evaluation on the preceptors was 3.37 in the 3-year analysis. The score was significantly higher for the preceptors of tertiary hospital pharmacies than those of general hospital pharmacies (3.61 vs. 3.25, P<0.001). For community pharmacy, no significant differences were found, depending on the types of pharmacy (3.53 vs. 3.43, P=0.309). Conclusion: The students' satisfaction with practice sites and preceptors in pharmacy experiential education was high. However, it varied greatly depending on the types of educational institutions. Mutual effort between university and educational institutions is required, to narrow the gap in the degree of students' satisfaction.

Background: Clostridium difficile associated diarrhea (CDAD) is a leading cause of hospital-associated gastrointestinal illness. Risk factors for CDAD include advanced age, long-term admission, antibiotics, proton-pump inhibitor or $H_2$ blocker use and immunosuppression. The practice guideline of American Journal of Gastroenterology (2013) suggests metronidazole for the first-line therapy of mild-moderate CDAD as well as vancomycin for severe CDAD. MICU inpatients receiving stress ulcer prophylaxis and antibiotics are susceptible to nosocomial CDAD. Therefore, this study aimed to evaluate occurrence and treatment of CDAD in MICU. Methods: Patients who were admitted to the MICU and had CDAD from August 2012 to August 2015 were analyzed retrospectively. Results: Of the 90 patients with CDAD, 20 patients (2.22%) had mild-moderate CDAD (16 received metronidazole and 4 received vancomycin therapy) and 70 patients (77.8%) had severe CDAD(54 received metronidazole and 16 received vancomycin therapy). Among the patients with mild- moderate CDAD, treatment with metronidazole or vancomycin resulted in same clinical cure in 50% of the patients (p=1.00). Among the patients with severe CDAD, treatment with metronidazole or vancomycin resulted in clinical cure in 40.7% and 50.0% of the patients, respectively (p=0.511). Clinical symptoms recurred in 7.4% of the severe CDAD patients treated with metronidazole and 6.3% of those treated with vancomycin(p=0.875). Conclusion: Our findings suggest that metronidazole and vancomycin are equally effective for the treatment of mild-moderate CDAD; however, vancomycin demonstrated higher clinical cure rate and lower recurrence rate for severe CDAD, although the difference was not statistically significant. For better clinical outcomes, appropriate medication use by disease severity is needed.

Background: Piperacillin/tazobactam (TZP) is an antibiotic against a broad spectrum of gram-positive, gram-negative, and aerobic and anaerobic strains of bacteria. Due to changes in its pharmacokinetic and pharmacodynamic parameters by TZP-treated patients' renal functions and obesity, it is important to administrate and monitor TZP based on their renal functions and Body Mass Index (BMI) levels. The purpose of this study was to determine the appropriateness of administration doses of TZP based on renal functions of obese cancer patients in a tertiary hospital. Methods: This study was retrospectively conducted with obese cancer patients with $BMI{\geq}30kg/m^2$ in a tertiary hospital, Korea from September 2004 to August 2014. Data were collected through Electronic Medical Record (EMR) which contained laboratory data and TZP dosing of each patient. Results: Among 7,058 patients during the study period, 102 prescriptions were selected based on inclusion and exclusion criteria and classified by their renal functions. Although TZP should be used based on patients' renal functions to adjust its dose, its initial dose and dosing interval were consistently used without considering patients' renal functions on a regular basis. Especially, in the comparison with FDA dosing standard of TZP, approximately twice patients with $20mL/min{\leq}CrCl{\leq}40mL/min$ received domestically 4.5 g instead of 2.25 g as the TZP starting dose. Conclusion: The appropriate doses of TZP were administered to almost all of obese cancer patients; however, the recommended TZP dose was different between Korea and other countries by twice the amount. Further related studies are necessary to clearly determine the results, to optimize TZP treatment for obese patients with cancer in clinical practice, and to design and develop new TZP formulations for them in pharmaceutical industry.

Background: Nebulized colistimethate is increasingly used, because there are problems such as renal dysfunction and low distribution within the lungs when colistimethate is administered intravenously. This study was designed to compare and analyze the changes in renal function by of nebulized colistimethate treatment for its safe administration. Methods: This study retrospectively reviewed the electronic medical records of adult patients above 19 years old, receiving only the nebulized colistimethate at least 4 days in Yonsei university health system from Nov 2014 to Aug 2015. Acute kidney injury (AKI) was determined by using the RIFLE criteria (Risk, Injury, Failure, Loss and End-stage renal disease) according to serum creatinine (SCr) levels before and after use of nebulized colistimethate. Results: 48 patients were included our study and their SCr increased significantly after nebulized colistimethate treatment ($SCr_0$ vs. $SCr_1$; $0.85{\pm}0.80$ vs. $1.00{\pm}0.82mg/dL$, n=48, p<0.001), but the changes were in normal range according to the standards at Yonsei university health $system^a$. Among 48 patients, 38 patients were in the non-AKI group (79.2%), and 10 patients developed AKI (20.8%). Within the AKI group, 2 patients were in the Injury group (20%) and the other 8 in the Risk group (80%). Conclusion: There was no significant difference in age, dosage and duration of treatment between AKI group and non-AKI group (p>0.05). The study has a significance in that it reviewed the safety of nebulized colistimethate only treatment to national patients, analyzing its nephrotoxicity. It has confirmed that nebulized colistimethate is a safer method than intravenous injection, and requires to establish a guideline for the use of nebulized colistimethate in further studies with broader patient groups. $^a$ : SCr Male 0.68-1.19 mg/dL, Female 0.49-0.91 mg/dL.

Objectives: This study aimed to compare effects on glycemic control and weight loss between the metformin/dapagliflozin combination and the metformin/sitagliptin combination in type 2 diabetic patients. Methods: This study retrospectively reviewed the medical records, from January $1^{st}$ 2015 to March $31^{st}$ 2016, of type 2 diabetic patients who were older than 18 and were prescribed with dapagliflozin or sitagliptin in combination with metformin. Hemoglobin $A_{1c}$ ($HbA_{1c}$) levels and weights were measured every 3 months. Results: The dapagliflozin group showed a greater decrease in $HbA_{1c}$ levels after 3 months (-0.75% vs. 0.01%, P<0.001), 6 months (-0.36% vs. 0.08%, P=0.029), and 9 months (-0.53% vs. 0.08%, P=0.046) compared to the sitagliptin group. Also, the dapagliflozin group showed a greater significant decrease in the rate of change in $HbA_{1c}$ levels after 3 months (-0.09 vs. 0.01, P<0.001), 6 months (-0.04 vs. 0.01, P=0.031), 9 months (-0.07 vs. 0.02, P=0.029), and 12 months (-0.05 vs. 0.05, P=0.047). Furthermore, the dapagliflozin group showed a greater decrease in amount of weight change after 3 months (-2.46 kg vs. 0.37 kg, P<0.001), 6 months (-3.02 kg vs. 0.13 kg, P<0.001), and 9 months (-2.27 kg vs. 0.50 kg, P=0.002). Finally, the dapagliflozin group showed a greater decrease in the rate of change in weight after 3 months (-3.10% vs. 0.52%, P<0.001), 6 months (-3.83% vs. 0.21%, P<0.001), 9 months (-2.84% vs. 0.79%, P=0.002), and 12 months (-4.91% vs. 0.44%, P<0.001). Conclusions: It was concluded that dapagliflozin is more effective than sitagliptin for type 2 diabetic patients.

Background: Generic medications are approved on the basis of bioequivalence with brand medications in healthy volunteers rather than the target population, there remains a substantial uncertainty regarding their clinical effectiveness and safety. The object of this paper is to compare the clinical equivalence of generic statin drugs in patients. Methods: Literature published before September 2016, which is indexed in PubMed, EMBASE, RISS, comparing generic to brand products in statins. Outcomes included blood lipid level, proportion of days covered (adherence), hospitalization and mortality. Results: 511 citations were screened, of which 11 studies met eligibility criteria (6 randomized clinical trials, 5 observational studies). Generic atorvastatin was clinical equivalent with brand drugs in blood lipid level (3 RCTs) and generic simvastatin was also clinical equivalent with brand drugs (2 RCTs). 2 of 3 studies reported no significant difference in proportion of days covered except 1 study which reported generic statin significantly enhance proportion of days covered (p<0.001). Hospitalization was no significant difference in all studies (p>0.05). 1 study reported that all cause of mortality was significantly low in generic drugs (p<0.0001). Conclusion: Published data on comparing clinical efficacy of generic and brand statins were insufficient in both quantity and quality. This systematic review suggests that additional studies on clinical equivalence and safety of generic medications in patients would be needed.

Objective: International institutes such as Global institute for Asthma(GINA), KAAACI(Republic of Korea), NHLBI(USA), BTS(UK) and JSA(Japan) have published guidelines for asthma treatment. The aim of this study was to compare the representatives' international guidelines of pharmacotherapy for pediatric asthma. Methods: The recommendations related to pharmacotherapy for pediatric asthma were extracted from the latest representatives' international guidelines, and comprehensive comparisons were conducted. Results: Major comparison outcomes between international guidelines were evaluated as follows: classification system on severity and pediatric age group, recommendation for inhaled corticosteroid dose, recommendation for pediatric age group of theophylline in mild asthma, and recommendation for pediatric age group of tiotropium in severe asthma. Clinical trials emphasized the adverse effects of theophylline, whereas tiotropium demonstrated beneficial actions for pediatric asthma. Therefore, theophylline was recommended for older patients with persistent asthma, and tiotropium was considered to be suitable for younger patients with severe asthma according to GINA guidelines. Conclusion: These findings address the requirement to harmonize international guidelines of pharmacotherapy in pediatric asthma. In addition, the findings suggest that KAAACI needs to update its pharmacotherapy guidelines of theophylline, tiotropium and other medicines recently approved.