Nirmatrelvir/ritonavir-induced elevation of blood tacrolimus levels in a patient in the maintenance phase post liver transplantation.

Nirmatrelvir is an orally administered anti-SARS-CoV-2 drug used in combination with ritonavir, the drug-metabolizing cytochrome P450 (CYP) 3A inhibitor, to evade metabolism and extend bioavailability. Meanwhile, the immunosuppressant tacrolimus is a CYP3A4/5 substrate, and CYP3A inhibition results in drug-drug interactions. Herein, we report the case of a coronavirus disease 19 (COVID-19) patient in the maintenance phase post liver transplantation, receiving tacrolimus treatment, with a marked increase of blood tacrolimus levels after the initiation of concomitant nirmatrelvir/ritonavir treatment.

Changes in Pharmacodynamic Parameters during Co-administration of 5-FU with Warfarin: A Retrospective Case Series.

Drug-drug interactions (DDIs) between warfarin (WF) and fluoropyrimidines are well known. Co-administration of WF and 5-fluorouracil (5-FU) leads to elevations in prothrombin time international normalised ratio (PT-INR). The inhibition of drug metabolism through suppression of CYP activity is a possible cause of prolonged PT-INR elevations.

Effect of 5-fluorouracil on mRNA expression of drug metabolizing enzyme and transporter genes in human hepatoma cell lines.

Fluoropyrimidines such as 5-fluorouracil (5-FU) are well known to have drug-drug interactions with anticoagulant medications such as warfarin. This study investigated the mRNA expression of pharmacokinetic (PK)-related genes in response to 5-FU using the hepatocarcinoma cell lines after examining relevant gene expression via RNA sequencing. We used HepaRG cells for 5-FU treatment analysis because these cells displayed PK-related gene expression.

Revised hospital antibiotic formulary reduces antimicrobial consumption and promotes a shift towards narrow-spectrum antibiotic usage.

Background: In Japan, the national action plan to adress antimicrobial resistance problems aimed to reduce the use of oral cephalosporins, quinolones, and macrolides per day per 1000 inhabitants by 50% from the levelin 2013 by 2020. The aim of this study was to evaluate the effects of a revised antibiotic formulary on in- and out-hospital oral antibiotic prescribing practices at a 600-bed university hospital.

Method: A retrospective before-and-after comparison study was conducted.

Therapeutic drug monitoring in peritoneal dialysis: A case of nontuberculous mycobacterium catheter-related infection treated with amikacin.

The pharmacokinetics of amikacin makes it difficult to predict the appropriate dosing to avoid harmful side effects in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). The implementation of therapeutic drug monitoring may be useful in controlling amikacin serum concentrations in patients receiving CAPD.

Long-term Treatment of Teicoplanin for Methicillin-resistant Staphylococcus aureus Sternal Osteomyelitis with Renal Impairment: A Case of High Teicoplanin Trough Levels Maintained by Therapeutic Drug Monitoring.

Teicoplanin, a glycopeptide antibiotic for methicillin-resistant Staphylococcus aureus, is recommended for therapeutic drug monitoring during treatment. Maintaining a high trough range of teicoplanin is also recommended for severe infectious disease. However, the optimal dose and interval of treatment for severe renal impairment is unknown.

Fixed eruption due to quinine in tonic water: a case report with high-performance liquid chromatography and ultraviolet A analyses.

Fixed drug eruption is a common cutaneous adverse reaction in young patients with a characteristic clinical appearance. However, the diagnosis and identification of the substance may be difficult if food or food additives provoke the fixed eruption. A 26-year-old man had a history of two episodes of cutaneous erythema with residual pigmentation.

The (R)-omeprazole hydroxylation index reflects CYP2C19 activity in healthy Japanese volunteers.

Purpose: Omeprazole has (R)- and (S)-enantiomers, which exhibit different pharmacokinetics (PK) among patients with cytochrome P450 (CYP) 2C19 genotype groups. The aim of this study was to investigate whether the 1-point, 4-h postdose (R)-omeprazole hydroxylation index (HI) of racemic omeprazole reflects the three CYP2C19 genotype groups in Japanese individuals.

Methods: Ninety healthy Japanese individuals were enrolled and classified into the three different CYP2C19 genotype groups: homozygous extensive metabolizers (hmEMs; n = 34), heterozygous EMs (htEMs; n = 44), and poor metabolizers (PMs; n = 12).

Am80 induces neuronal differentiation via increased tropomyosin-related kinase B expression in a human neuroblastoma SH-SY5Y cell line.

Am80, a synthetic retinoid, has been used in differentiation therapy for acute promyelocytic leukemia (APL). All-trans retinoic acid (ATRA) as one of natural retinoid has been also used to treat APL. ATRA treatment causes neuronal differentiation by inducing tropomyosin-related kinase B (TrkB) expression and increasing the sensitivity to brain-derived neurotrophic factor (BDNF), a TrkB ligand.

Hydroxylation of R(+)- and S(-)-omeprazole after racemic dosing are different among the CYP2C19 genotypes.

Purpose: To elucidate the stereoselective pharmacokinetics of omeprazole enantiomers and their metabolites after racemic IV dosing because there is little information about the stereoselective metabolism of omeprazole in in vivo study.

Methods: Seventeen subjects were classified into three CYP2C19 groups based on their genotypes: homozygous extensive metabolizers (hmEMs; n = 5), heterozygous EMs (htEMs; n = 7) and poor metabolizers (PMs; n = 5).

Results: After single IV administration of racemic omeprazole (20 mg), the mean area under the plasma concentration-time curve (AUC(0-∞)) of R(+)-omeprazole in PMs was significantly higher than that in hmEMs and htEMs, while that of S(-)-omeprazole was no significance among three genotypes because of a wide inter-individual variability.

Chiral assay of omeprazole and metabolites and its application to a pharmacokinetics related to CYP2C19 genotypes.

Studies investigating the relationship between CYP2C19 genotype and the stereoselective metabolism of omeprazole have not been reported. In the present study, we developed a simple and sensitive analytical method based on column switching reversed phase high-performance liquid chromatography (HPLC) with UV detection to determine the concentrations of (R)- and (S)-omeprazole and of its principal metabolites, (R)- and (S)-5-hydroxyomeprazole, and the non-chiral, omeprazole sulfone, in human plasma. Sample preparation involved liquid-liquid extraction with diethyl ether:dichloromethane (60:40, v/v) followed by clean-up on a TSK BSA-ODS/S column (5 μm, 10 mm × 4.

Am80 induces neuronal differentiation in a human neuroblastoma NH-12 cell line.

Retinoids including natural vitamin A, its derivatives and synthetic compounds work as transcription factors through the retinoic acid receptors (RAR, RXR). All-trans retinoic acid (ATRA), a family of retinoids, is an internal ligand of RAR and well known as a useful differentiation inducer to treat acute promyelocytic leukemia (APL). ATRA therapy is now established as an initial treatment for APL.

Spinal ERK activation via NO-cGMP pathway contributes to nociceptive behavior induced by morphine-3-glucuronide.

Intrathecal (i.t.) injection of morphine-3-glucuronide (M3G), a major metabolite of morphine without analgesic actions, produces a severe hindlimb scratching followed by biting and licking in mice.

Novel chronotherapeutic rectal aminophylline delivery system for therapy of asthma.

The aim of this study was to develop a new chronotherapeutic pharmaceutical preparation as a sustained-release suppository for prevention and therapeutic use against bronchial asthma in the early morning. Sustained-release hollow-type (SR-HT) suppositories using sodium alginate (Alg-Na), sodium polyacrylate (PANa) or polyacrylate-PANa co-polymer (PA-PANa) as gelling polymers (gel agent) were prepared and pharmaceutical characteristics of these suppositories were investigated. Type A SR-HT suppositories comprised a suppository shell prepared with oleaginous base and containing aminophylline only or aminophylline with Alg-Na or PANa in the cavity (hollow space).