Yet Another Doctor Blog On The Internet

Immunosuppressants leflunomide and mycophenolic acid inhibit fibroblast IL-6 production by distinct mechanisms.

2017-05-11

Statins reduce infarct size by upregulating nitric oxide synthases and PGI2 production. In this article, the infarct size-limiting effect of low-dose simvastatin + ezetimibe, ezetimibe, and high-dose statins were compared. Rats received 3-day water, atorvastatin (10 mg/kg/d), simvastatin (10 mg/kg/d), simvastatin (2 mg/kg/d), simvastatin (2 mg/kg/d) + ezetimibe (1 mg/kg/d), or ezetimibe. Rats underwent 30-minute coronary artery occlusion and 4-hour reperfusion. Atorvastatin and simvastatin 10 reduced infarct size, whereas simvastatin 2, ezetimibe, and simvastatin 2 + ezetimibe had no effect. Atorvastatin and simvastatin 10 increased nitric oxide synthases activity, whereas simvastatin-2, ezetimibe, and simvastatin-2 + ezetimibe had only a small effect. Atorvastatin and simvastatin 10 significantly increased myocardial 6-ketoprostaglandin F(1 alpha) levels, whereas simvastatin 2, ezetimibe, and simvastatin 2 + ezetimibe had no effect. High-dose statin is required to decrease infarct size, upregulate myocardial nitric oxide synthases activities, and increase 6-keto prostaglandin F(1 alpha) levels. Combination of ezetimibe and low-dose statin is ineffective in modulating myocardial biochemical changes associated with cardioprotection.

The aim of these studies was to assess the long-term tolerability and effects on lipids of ezetimibe coadministered with pravastatin or simvastatin during treatment of hypercholesterolemic patients.

Mean LDL-C was reduced by 28%/27% (study 1/ study 2) compared with baseline values (on statin monotherapy). Mean total cholesterol was decreased by 22% in each study, mean triglycerides by 16/17%, and mean high density cholesterol (HDL-C) was increased by 9/10%. Adverse events were reported in 0.3% and 0.2% of patients, respectively.

After a placebo run-in period, the effects of simvastatin alone (S) or simvastatin + ezetimibe (S+E) were compared in a randomized, double-blind, cross-over study on inflammatory parameters. Eighteen DM patients with estimated glomerular filtration rate (eGFR) 15-59 mL/min × 1·73 m(2) (CKD stages 3-4) (DM-CKD) and 21 DM patients with eGFR > 75 mL/min (DM only) were included.

To investigate whether LDL-C-lowering alleles in or near NPC1L1 and other genes encoding current or prospective molecular targets of lipid-lowering therapy (ie, HMGCR, PCSK9, ABCG5/G8, LDLR) are associated with the risk of type 2 diabetes.

We enrolled 144 patients of whom 120 had blood available for final analysis. The coadministration of ezetimibe with ongoing simvastatin therapy resulted in a statistically significant additional reduction in LDL-C concentration as compared with simvastatin monotherapy (-26.7 versus -9.1%, respectively; total additional reduction of 17.6%, P < 0.0001). More patients in the ezetimibe and simvastatin group achieved NCEP ATP III LDL-C target levels than in the simvastatin monotherapy group (70 versus 33%, respectively; P = 0.0001). The coadministration of ezetimibe with simvastatin was well tolerated with a safety profile similar to that of simvastatin monotherapy.

Ezetimibe blocks intestinal absorption of sterols via interaction with the Neimann-Pick C1-Like 1 (NPC1L1) transporter and is approved for use in the treatment of primary hyperlipidemia (heterozygous familial and non-familial), homozygous familial hypercholesterolemia, and homozygous sitosterolemia. A recently completed randomized clinical trial [simvastatin and ezetimibe in aortic stenosis (SEAS)] testing the effectiveness of Vytorin (a combination of simvastatin and ezetimibe) in patients with aortic stenosis reported an unexpected safety finding: an increase in overall cancer incidence and cancer-associated mortality (all types) in the treated groups relative to the placebo control. A subsequent meta-analysis utilizing a much larger database from two ongoing clinical trials indicated that the observed findings in the SEAS trial were likely due to chance and not a true drug-induced effect. Nonetheless, it has been suggested by various commentators on the SEAS trial that ezetimibe may be carcinogenic. The extensive nonclinical database for ezetimibe was used to test the hypothesis that ezetimibe may be a direct or indirect carcinogen. Using two different in silico approaches, ezetimibe showed no structural alerts for genetic toxicity or carcinogenicity. Ezetimibe was not genotoxic in two reverse mutation assays, one in vitro clastogenicity assay, and two mouse micronucleus assays. No evidence of proliferative lesions was observed in three species in studies of 1-12 months in duration. Ezetimibe was not carcinogenic in standard 2-year bioassays in mice and rats. Additionally, in these 2-year bioassays, no drug-related non-neoplastic lesions were noted. The absence of drug-induced non-neoplastic or proliferative lesions in these studies indicates that ezetimibe treatment was not associated with findings characteristic of carcinogens (i.e., DNA reactivity or cell proliferation) Administration of pharmacologic doses of ezetimibe to mice did not alter hepatic expression patterns of genes associated with apoptosis, cell proliferation, or epithelial-mesenchymal transition. No evidence of drug-induced tumors was observed in mice in which the molecular target of ezetimibe (NPC 1L1) was knocked out over the life span of the animal. In conclusion, the nonclinical data do not support the proposed hypothesis based on the single observation from the SEAS trial and, rather, support the conclusion that ezetimibe does not represent a carcinogenic hazard to humans using this drug in a therapeutic setting.