Saiseikai Yokohama-shi Nanbu Hospital has been charging an additional fee for enhanced collaboration for surgical patients concerning outpatient cancer drug chemotherapy since March 2022. In this survey, we compared the number of consultations and pharmacological interventions performed by pharmacists for target and non-target departments from September 2021 to February 2022 before the calculation began, and from March to August 2022 after the calculation started. In the target department, the number of consultations was 1.5±1.3 and 8.1±4.8 per day for before and after the calculation began, respectively, showing a significant increase (P<0.001). The number of pharmacological interventions increased from 35 preoperatively to 66 postoperatively. However, in the non-target departments, there was no change in the number of consultations and pharmacological interventions between before and after the calculation started. The results suggest that the additional fee for enhanced collaboration effectively enables pharmacists to continuously intervene in pharmacological problems.

Objective: Risk factors for hypermagnesemia due to magnesium oxide (MgO) include advanced age, decreased renal function, and long-term administration; however, no study has evaluated patients that present all of these factors. This study was aimed to evaluate the safety of long-term MgO administration in elderly patients with impaired renal function.Methods: We investigated changes in serum Mg in patients aged 65 years or older, who had been taking oral MgO and presenting a glomerular filtration rate (eGFR) ＜60 mL/min/1.73 m2 for 6 months or longer.Results: Thirty patients were surveyed. Their median age was 81 years (range, 68-92). No significant change in patient background was observed before and after initiating MgO administration, with no change in serum Mg detected. Furthermore, the oral dose of MgO was divided into groups taking ＜1,000 mg and ≥ 1,000 mg; no change in serum Mg was observed in either group. Based on renal function, the analysis was divided into a mildly decreased group (60＞ eGFR ≥ 45) and a moderately to severely decreased group (45＞ eGFR ≥ 15), and no change in serum Mg was observed in either group.Conclusions: We targeted elderly patients with renal dysfunction who were taking long-term MgO, a known risk factor for hypermagnesemia, indicating that MgO can be safely continued.