Toshihiro Ishii

A frameshift variant of CYP2C8 was identified in a patient who suffered from rhabdomyolysis after administration of cerivastatin

AbstractA hypercholesterolemic patient medicated with cerivastatin for 22 days resulted in acute rhabdomyolysis. CYP2C8 and CYP3A4 are the major enzymes responsible for the metabolism of cerivastatin, and a transporter, OATP2, contributes to uptake of cerivastatin to the liver. In this study, the patients DNA was sequenced in order to identify a variant that would lead to the adverse effect of cerivastatin. Three nucleotide variants, 475delA, G874C, and T1551C, were found in the exons of CYP2C8. The patient was homozygous for 475delA variant that leads to frameshift and premature termination. Accordingly, the patient is most likely lacking the enzyme activity. The patients children were both heterozygous for the mutation. The patient had three nucleotide variants in exon 4 (A388G) and exon 5 (C571T and C597T) of OATP2 that were all heterozygous. No nucleotide variation in the exons of CYP3A4 was identified. To our knowledge, this is the first report showing that the adverse effect of cerivastatin might be caused by the genetic variant of CYP2C8.

Clearance rates of cerivastatin metabolites in a patient with cerivastatin‐induced rhabdomyolysis

We report on a patient who developed acute rhabdomyolysis after taking cerivastatin. A 74‐year‐old hypercholestrerolaemic woman taking cerivastatin (0·15 mg/day) for 22 days complained of general muscle weakness and muscle pain. Her serum creatinine phosphokinase level was 19 190 IU/L. Serum myoglobin was over 3000 ng/mL. Serum concentration of cerivastatin at 6 h after taking the last dose (0·15 mg) was 8062·5 ng/L, which was almost 5·7 times higher than that of normal persons. The serum concentration of cerivastatin showed that the half‐life of cerivastatin in this patient was 22·4 h, compared with 2·4 h for normal controls. Cerivastatin is catabolized by cytochrome P450, 3A4 and 2C8 to M‐1, and by 2C8 to M‐23. The ratio of M‐23 to M‐1 in her serum was much lower than that of control persons (0·64 vs. 2·08). She had previously taken simvastatin which is metabolized by CYP3A4, without any sign and symptoms of rhabdomyolysis. These results suggest that the slowed clearance of cerivastatin in this patient might have been compounded by cytochrome P450, 2C8 dysfunction.

Time-Dependent Alterations of Vancomycin-Induced Nephrotoxicity in Mice

Vancomycin hydrochloride (VCM) is a glycopeptide antibiotic that is commonly used against methicillin-resistant, Gram-positive cocci despite the nephrotoxic side effects. VCM-induced nephrotoxicity has been reported in 5-28% of recipient patients. Therefore, renal failure induced by VCM has become an important clinical problem. However, the exceedingly complex mechanism of VCM-induced nephrotoxicity is not fully understood. Therefore, this study was designed to clarify time-dependent alterations of VCM-induced nephrotoxicity in mice as a step toward decreasing the risks of kidney injury associated with VCM therapy. VCM was injected intraperitoneally into mice at a dose of 400 mg/kg body weight at 24-h intervals for 3, 5, 7, and 14 d. At 24 h after the last injection, we examined histopathological alterations of the kidney as well as blood biochemistry. VCM administration resulted in a decrease of body weight and increase of kidney weight. Histological examination revealed renal damage such as dilated proximal tubules with occasional casts and interstitial fibrosis in VCM-treated mice. Furthermore, immunohistochemical staining with anti-CD10 and anti-single-stranded DNA antibodies highlighted damaged renal proximal tubules with marked dilatation as well as numerous apoptotic cells as early as day 4 of VCM-treatment. The severity of symptoms progressed until day 15. These results suggest that VCM-induced renal damage and incipient renal failure begin soon after the start of treatment and progressively worsen. This is the first report describing the time-dependence of VCM-induced nephrotoxicity in mice and depicting a model that clarifies the mechanisms of this tissue damage.

Importance of Efficient Coordination of Long-Term, Large-Scale Clinical Trials and Problems Arising-Role of Hospital Pharmacists in this Activity-

We felt that pharmacists should participate more actively in the evaluation of efficacy and safety in clinical trials. To improve the capability of pharmacists in this respect, we evaluated the support we gave to the investigators of the Japan EPA Lipid Intervention Study (JELIS), a long-term, large-scale clinical trial conducted at the Department of Pharmacy of our hospital. To identify the problems in our support, we investigated the number of days required to complete the Case Report Form (CRF) and the reliability of the data collected, by considering the adequacy of the items observed and the clinical inspection terms. Our findings indicated that it was feasible for pharmacists to handle the coordination of JELIS in addition to their everyday workload and we also noted an improvement in the clinical inspection rate, from 76.6% to 100% for JELIS I and from 97.5% to 100% for JELIS II. Moreover, we found the number of days required to complete the CRF was reduced from 109.8 days to 20.3 days for JELIS I and from 79.5 days to 21.0 days for JELIS II. These results show that the pharmacists in our hospital helped to maintain the reliability of clinical data.