Validation of a Nomogram for Achieving Target Trough Concentration of Vancomycin: Accuracy in Patients With Augmented Renal Function.

BACKGROUND: Adjustment of initial vancomycin (VCM) dosage has been recommended on the basis of the renal function nomogram in therapeutic drug monitoring guidelines in Japan. However, this nomogram has not been clinically validated, and few studies have focused on its usefulness in patients with risk of augmented renal function. Therefore, this study aimed to evaluate the validity of the VCM nomogram and the association between patient conditions related to augmented renal function and its accuracy. METHODS: In this retrospective study, we screened data of 398 patients who received VCM and had estimated glomerular filtration rates ≥30 mL·min·1.73 m. Patients who met nomogram dosing criteria were categorized into a nomogram group, and the associations of age, renal function, and individual conditions such as febrile neutropenia, solid tumor, blood cancer, and brain injury with subtherapeutic concentrations (<10.0 mcg/mL) of VCM were evaluated. RESULTS: In total, 177 patients were categorized into the nomogram group, and 83 (47%), 81 (46%), and 13 patients (7%) had VCM trough concentrations of 10-20, <10, and >20 mcg/mL, respectively. Age <50 years was only significantly associated with subtherapeutic trough concentrations. Specific conditions of patients such as febrile neutropenia, solid tumor, and blood cancer were associated with elevated VCM clearance; however, there was no decline in trough VCM concentrations regardless of the presence of the specific conditions. CONCLUSIONS: The Japanese VCM dosing nomogram was effective in minimizing the number of instances of supratherapeutic VCM serum concentrations; however, it lacked accuracy in achieving target trough concentrations. The accuracy of the nomogram could be enhanced by categorizing patients according to age. Nevertheless, this study provides novel evidence of the usefulness of this nomogram in avoiding subtherapeutic concentrations of VCM in patients with risk factors for augmented renal clearance.

Augmented Renal Clearance in Patients With Febrile Neutropenia is Associated With Increased Risk for Subtherapeutic Concentrations of Vancomycin.

BACKGROUND: Augmented renal clearance (ARC) has frequently been observed in critically ill patients. The risk factors for ARC in patients, including those in the general ward, and their influences on vancomycin (VCM) treatment remain unclear. The aims of this study were to investigate the risk factors for ARC and to evaluate the influence of ARC on the pharmacokinetic parameters of VCM. METHODS: This study included a total of 292 patients with VCM treatment who had normal serum creatinine concentrations. ARC was defined by an estimated creatinine clearance ≥130 mL·min·1.73 m. The risk factors for ARC were determined with stepwise logistic regression analysis. The pharmacokinetic parameters of VCM were estimated through the Bayesian method using a 2-compartment model. RESULTS: ARC was observed in 48 patients (16.4%). Age ≤65 years [odds ratio (OR): 5.77; 95% CI: 2.89-11.97; P < 0.0001], brain injury (OR: 5.11; 95% CI: 1.49-17.57; P = 0.0086), febrile neutropenia (OR: 2.76; 95% CI: 1.11-6.67; P = 0.0254), and a mean volume of infusion fluid ≥1500 mL/d (OR: 2.53; 95% CI: 1.27-5.16; P = 0.0091) were independent risk factors for the occurrence of ARC. The patients with ARC exhibited higher VCM clearance values than the non-ARC patients. The median trough serum concentrations of VCM were 7.4 (interquartile range: 5.2-11.6) mcg/mL in the ARC patients and 12.2 (8.9-16.3) mcg/mL in the non-ARC patients (P < 0.0001). Subtherapeutic trough concentrations of VCM (<10.0 mcg/mL) were found in 68.8% of the ARC patients and in 32.8% of the non-ARC patients (P < 0.0001). CONCLUSIONS: This observational study investigated the influence of febrile neutropenia on the emergency of ARC for the first time. ARC was strongly associated with VCM pharmacokinetics, and two-thirds of the ARC patients had subtherapeutic VCM concentrations. In patients with ARC, individualized dosing regimens are required to achieve the target trough concentration.

Risk factors for hypernatremia in patients with short- and long-term tolvaptan treatment.

PURPOSE: The long-term efficacy of tolvaptan, a vasopressin V2 receptor antagonist, has been reported. However, the safety of long-term treatment remains to be fully elucidated. We assessed the safety profile of tolvaptan with respect to hypernatremia. METHODS: This retrospective study included 371 patients treated with tolvaptan. Risk factors for hypernatremia (serum sodium concentration ≥147 mEq/L) were determined. RESULTS: Hypernatremia occurred in 95 patients (25.6 %), of whom 71 (19.1 %) developed hypernatremia within 7 days of tolvaptan treatment (early onset). Stepwise logistic regression analysis demonstrated that baseline serum sodium ≥140 mEq/L, an initial tolvaptan dosage >7.5 mg, and a BUN/serum creatinine ratio ≥20 were independent risk factors for early onset of hypernatremia. Tolvaptan was prescribed for more than 7 days to 233 patients, of whom 123 were administrated tolvaptan for more than 1 month. Hypernatremia occurred in 24 of these patients (10.3 %) (late onset). Predictive factors for late onset of hypernatremia were an average daily dosage of tolvaptan >7.5 mg and age ≥75 years. CONCLUSIONS: A daily dosage of 7.5 mg or less was recommended to prevent hypernatremia in short- as well as long-term tolvaptan treatment, and mainly elderly patients were at risk for hypernatremia.

A case-control study showing low creatinine clearance and high magnesium intake as risk factors for hypermagnesemia in older individuals.

According to epidemiological studies, constipation has a negative effect on life expectancy, necessitating appropriate treatment. According to the Pharmaceuticals and Medical Devices Agency (PMDA), patients who have been taking magnesium oxide (MgO) for constipation over a prolonged period, especially those with impaired renal function and older individuals, are at high risk of hypermagnesemia. Therefore, serum Mg levels, which are often not checked in clinical practice, should be monitored in these patients. Thus, to predict elevated serum Mg levels and prevent the development of hypermagnesemia, we aimed to identify the risk factors of hypermagnesemia, especially in the older population. Our study included patients who were prescribed MgO at our hospital between January 1, 2014, and March 31, 2016. Patients who did not meet the inclusion criteria were excluded and matched to adjust for background factors; finally, 35 patients in the hypermagnesemia arm and 140 patients in the non-hypermagnesemia arm were included in the analysis. Multivariate analysis identified estimated creatinine clearance (eCcr) ≤ 28.2 mL/min as a statistically significant risk factor. In addition, MgO dose ≥ 900 mg/day was identified as a risk factor for clinical consideration, although not statistically significant. Furthermore, the incidence of hypermagnesemia was shown to increase to 11.6% for those with MgO dose ≥ 900 mg/day, 27.0% for those with eCcr ≤ 28.2 mL/min, and 53.1% for those with both. Hypermagnesemia may occur in older patients with eCcr ≤ 28.2 mL/min who take more than 900 mg/day of MgO.

Case Reports of Transdermal Fentanyl Patch Administration Difficulties in Cancer Patients with Excess Sweating.

(Case 1) A 45-year-old male was diagnosed with prostate cancer. Treatment was administered using bicalutamide and leuprorelin acetate, while a transdermal fentanyl (TDF) was applied for pain relief. However, TDF continued to peel off owing to excessive sweating, even when reinforced by a protective layer. As such, TDF was discontinued and pain control was initiated using other medicines. Sweating occurred irregularly because of hot flashes, approximately four to five times per day. (Case 2) A 37-year-old male was diagnosed with a malignant thymoma and sacral metastasis. For analgesic control, etodolac tablets, carbamazepine tablets, and TDF were administered. Subsequently, the dose of the TDF was gradually increased, but the analgesic effect was low; thus, fentanyl blood concentration was measured. The measurements showed that even higher TDF doses did not increase fentanyl blood levels. During this period, full body sweating began to occur to a large extent due to unknown causes, and it was thought that the absorption of fentanyl decreased. When using a TDF, it is necessary to monitor patients for any sweating during treatment, while also considering changes in medication in some cases. This should promote the maintenance and improvement of the quality of life of the affected patients.

[Significant Prolongation of the International Normalized Ratio Associated with COVID-19 Treatment: Possible Drug Interaction with Remdesivir].

A 55-year-old man with hypertrophic cardiomyopathy and a pacemaker was admitted with coronavirus disease 2019 (COVID-19). Before admission, the patient's medications included amiodarone, diltiazem, bisoprolol, atorvastatin, etizolam, and warfarin (WF). After admission, dexamethasone (DXM) and remdesivir (RDV) were initiated for treating COVID-19. The international normalized ratio (INR) on admission was 1.8, which increased to 3.4 on day 5 and to 6.9 on day 10 after admission. Although there have been reports that RDV may occasionally prolong prothrombin time and that the degree of prolongation is often less severe, the mechanism of action has not been elucidated till date. There are reports of prolonged INR when WF is co-administered with RDV and DXM, suggesting that drug interactions may be a potential cause for the prolongation. A similar drug interaction may have potentially occurred in the case reported here. In addition, this case used amiodarone (AMD), and it has been reported that the RDV concentration increases when used in combination with AMD. Further investigations are needed to elucidate the cause of INR prolongation. Thus, close monitoring of the patient is recommended when RDV is co-administered with high-risk agents to avoid unnecessary side effects.

Suppressive efficacies of antimicrobial agents against human peripheral-blood mononuclear cells stimulated with T cell mitogen and bacterial superantigen.

The immunomodulatory efficacies of 12 antimicrobial agents clinically used were examined against T cell mitogen- or bacterial superantigen-induced proliferation of peripheral-blood mononuclear cells of healthy subjects. Minocycline (CAS 13614-98-7), rifampicin (CAS 13292-46-1), trimethoprim (CAS 738-70-5), and ribavirin (CAS 36791-04-5) significantly inhibited the proliferation of mitogen-stimulated mononuclear cells at 1-100 microg/ ml (p < 0.001), whereas ofloxacin (CAS 82419-36-1) enhanced the proliferation (p < 0.001). Ampicillin (CAS 69- 53-4), lincomycin (CAS 859-18-7), vancomycin (CAS 1404-93-9), sulfamethoxazole (CAS 723-46-6), fosfomycin (CAS 26016-99-9), colistin (CAS 1264-72-8), and polymyxin B (CAS 1405-20-5) showed no significant effect. Minocycline, rifampicin, trimethoprim, and ribavirin also inhibited the proliferation of superantigen-stimulated peripheral-blood mononuclear cells at 1-100 microg/ml (<0.001), whereas ofloxacin stimulated the proliferation (p < 0.001). Rifampicin and minocycline at 10-100 microg/ml significantly inhibited interleukin-2 production from mitogen- or superantigen-stimulated peripheral-blood mononuclear cells (p < 0.025). These results suggest that certain kinds of antimicrobial agents inhibited the proliferation of mitogen- and superantigen-stimulated human peripheral-blood mononuclear cells and suppressed interleukin-2 production from these cells. The ofloxacin effect is immunostimulative, while the drug did not influence the interleukin-2 production.