Drug therapy is necessary to treat metastatic and recurrent breast cancer. In Japan, two types of cyclin-dependent kinases (i.e., CDK4/6 inhibitors) are covered under the national healthinsurance system: palbociclib (since December 2017) and abemaciclib (since November 2018). Although there are many reports on the use and side effects of palbociclib in clinical practice, there are few such reports on abemaciclib. Therefore, we investigated the rate of neutropenia and associated background factors in patients taking abemaciclib. Of the 39 patients taking abemaciclib recruited for the study, 22 satisfied the inclusion criteria. Of these, 7 developed Grade 3 or higher neutropenia and had a significantly lower body weight and body mass index (BMI). Furthermore, the white blood cell and neutrophil counts before administration were significantly lower in the expression group compared with the non-expressing group. To predict the development of Grade 3 or higher neutropenia, the receiver operating characteristic (ROC) curve was used to calculate a BMI cut-off value of 23.9 (specificity 85.7%, sensitivity 73.3%, area under the ROC curve 0.80). Based on this cut-off value, BMI was divided into two groups (<23.9 and ≥23.9) and Fisher's exact test was performed. Patients with a low body mass index were more likely to develop Grade 3 or higher neutropenia as a result of increased dosage per kilogram body weight, while among patients with BMI < 25, those with BMI < 23.9 were at high risk of developing Grade 3 or higher neutropenia. Accordingly, caution is required in the treatment of such patients.

Hospitalized patients often have insomnia, and in many cases it is necessary to administer hypnotics. Although the hypnotics currently used in Japan are mainly benzodiazepine receptor agonists, there is an associated risk of falling due to muscle relaxant action, and carryover effect. It is believed that orexin receptor antagonists, which have a different mechanism of action from conventional hypnotics, have no muscle relaxant action and are thus considered to be much safer. Therefore, in this study we compared fall rate according to the class of hypnotics that the patient had been taking. 　　We analyzed hospitalized patients taking orexin receptor antagonists (ORB), benzodiazepines (BZDs), and non-BZDs, who had falls and were treated in our hospital from April 1, 2017 to December 31, 2017. Patients were grouped according to the drug they were taking before the fall occurred and the fall rate was calculated and compared. The total number of falls in the target patients was 45, and the total number of people prescribed hypnotics in the study period was 1682. Fall rate by classification of hypnotics was the lowest in the ORB group at 1.45％, which was significantly lower than that of the BZD group, suggesting the possibility that ORBs have minimal influence on falls. In addition, the fall rate in the non-BZD group was significantly lower than that of the BZD group.

In hemodialysis, an adsorbent is used to remove phosphorus from the blood.Because phosphorus adsorbents contain iron, they may cause iron excess, and appropriate management is thus required.In recent years, the use of sucroferric oxyhydroxide (SO), which has become available, is said to be associated with lower iron absorption and is less likely to cause iron excess, as compared with conventional ferric citrate hydrate (FCH). However, in clinical trials of SO conducted in Japan, serum ferritin (Ft) and transferrin saturation (TSAT) tended to increase, and this may cause iron excess similar to FCH. Therefore, we report here on the phosphorus adsorption effect and the influence on iron-related benefit of SO.Among 12 patients, iron-related abnormalities were observed in 3 patients and adverse events such as diarrhea and nausea were observed in 7 patients.In 8 patients who continued taking SO for up to 24 weeks, serum phosphorus (P) decreased, Ft and TSAT increased, Hb, Fe, Ca did not change significantly, and the dose of erythropoiesis-stimulating agents (ESA) decreased. The rate of change of Ft was greater in 5 patients with iron deficiency than in 3 patients with non-ferrous deficiency. SO administration tended to decrease P and improve iron deficiency.In addition, there was a decrease in the dose of ESA, suggesting the possibility of contributing to pharmaceutical cost reduction.Conversely, in patients with iron deficiency, iron-related abnormalities were observed in 3 patients, and about half had adverse events with subjective symptoms 4 weeks after the start of treatment with SO.Therefore, the administration of SO takes into account the effects on iron-related values as well as FCH, it is thus considered important to adjust the dose of SO or ESA depending on the condition while monitoring clinical laboratory values and adverse events from the beginning of administration.