A case of hypophosphatemia and elevated intact fibroblast growth factor 23 levels after short-term saccharated ferric oxide administration in a young woman and database analysis of adverse drug reactions in Japan.

Intravenous iron replacement therapy is a common treatment for iron deficiency. Commonly used agents in this treatment include ferric carboxymaltose, ferric derisomaltose, and saccharated ferric oxide (SFO). These drugs are known to elevate fibroblast growth factor 23 levels, resulting in hypophosphatemia, but in past reports, hypophosphatemia attributable to SFO treatment has been associated mainly with prolonged administration over several weeks. The present study details our experience of a case of moderate hypophosphatemia (<2 mg/dL) in a 22-year-old woman who had no specific history of hypophosphatemia during the first 5 days of SFO treatment, and showed an increase in intact fibroblast growth factor 23 levels within the first week of treatment. Cases of hypophosphatemia have been reported as occurring as early as 1 week after the start of SFO administration in the Japanese Adverse Drug Event Report database. These cases, along with our case, underline the need for awareness of the possibility of hypophosphatemia from the early stage of SFO administration, regardless of the patient's age or dosage, as well as the need to monitor patients to prevent complications.

Eicosapentaenoic acid increases proportion of type 1 muscle fibers through PPARδ and AMPK pathways in rats.

Muscle fiber type composition (% slow-twitch and % fast-twitch fibers) is associated with metabolism, with increased slow-twitch fibers alleviating metabolic disorders. Previously, we reported that dietary fish oil intake induced a muscle fiber-type transition in a slower direction in rats. The aim of this study was to determine the functionality of eicosapentaenoic acid (EPA), a unique fatty acid in fish oil, to skeletal muscle fiber type and metabolism in rats. Here, we showed that dietary EPA promotes whole-body oxidative metabolism and improves muscle function by increasing proportion of slow-twitch type 1 fibers in rats. Transcriptomic and metabolomic analyses revealed that EPA supplementation activated the peroxisome proliferator-activated receptor δ (PPARδ) and AMP-activated protein kinase (AMPK) pathways in L6 myotube cultures, which potentially increasing slow-twitch fiber share. This highlights the role of EPA as an exercise-mimetic dietary component that improves metabolism and muscle function, with potential benefits for health and athletic performance.

Hyperkalemic effect of drug-drug interaction between esaxerenone and trimethoprim in patients with hypertension: a pilot study.

BACKGROUND: We examined whether the pharmacodynamic drug-drug interaction between esaxerenone and trimethoprim enhances the hyperkalemic effect. METHODS: A retrospective observational study was conducted to identify patients >18 years undertaking esaxerenone alone or esaxerenone plus trimethoprim at Mie University Hospital from May 2019 to December 2022. We performed propensity score-matching (1:1) to compare between-group differences in the maximum change in serum potassium levels (ΔK) using the Mann-Whitney U test. For esaxerenone plus trimethoprim, Spearman's correlation coefficients were used to examine correlations between ΔK and variables, including changes in blood urea nitrogen (ΔBUN), serum creatinine levels (ΔCr), and weekly trimethoprim cumulative dose. RESULTS: Out of propensity score-matched groups (n=8 each), serum potassium levels significantly increased after administration of esaxerenone alone (4.4 [4.2 to 4.7] meq/L to 5.2 [4.7 to 5.4] meq/L, p=0.008) and esaxerenone plus trimethoprim (4.2 [4.0 to 5.1] meq/L to 5.4 [4.7 to 5.5] meq/L, p=0.023). ΔK did not significantly differ between the groups (esaxerenone alone; 0.6 [0.3 to 0.9] meq/L vs. esaxerenone plus trimethoprim; 1.0 [0.4 to 1.3] meq/L, p=0.342). ΔK positively correlated with ΔBUN (r=0.988, p<0.001) or ΔCr (r=0.800, p=0.017). There was a trend of correlation of ΔK with a weekly cumulative trimethoprim dose (r=0.607, p=0.110). CONCLUSIONS: The hyperkalemic effect of the drug-drug interaction between esaxerenone and trimethoprim is not notable and related to renal function and trimethoprim dosage.

Drug-drug interaction signals between loop diuretics and teicoplanin during acute kidney injury evaluated using Japanese spontaneous adverse drug event reports.

Teicoplanin can cause acute kidney injury, but little is known about the risk of acute kidney injury when teicoplanin is co-administered with loop diuretics (a powerful diuresis), which can alter renal hemodynamics and glomerular filtration rate. We performed a signal detection analysis using a Japanese adverse event database to determine the additive impact of loop diuretics on acute kidney injury associated with teicoplanin. The dataset originated between April 2004 and August 2022. Disproportionality analysis was performed to detect the signals for acute kidney injury (the Standardized MedDRA Query) when co-administered teicoplanin or vancomycin (a positive control) with individual diuretics, including loop diuretics. Multivariate logistic regression analysis was tested to estimate the adjusted reporting odds ratio (aROR) and 95% confidence interval (95% CI). There were 147 and 515 events of acute kidney injury associated with teicoplanin and vancomycin, respectively. A significant positive signal for acute kidney injury when teicoplanin was co-administered with loop diuretics was present (aROR 4.83, 95% CI 3.52-6.61, p < 0.0001). Contrastingly, no significant signals were observed when vancomycin was co-administered with any diuretics. These findings suggest that co-administered loop diuretics may have an unfavorable effect on acute kidney injury while undertaking teicoplanin but not vancomycin.