The safety profile of sustained-release etodolac

A window-of-opportunity biomarker study of etodolac in resectable breast cancer

Observational data show that nonsteroidal anti-inflammatory drug (NSAID) use is associated with a lower rate of breast cancer. We evaluated the effect of etodolac, an FDA-approved NSAID reported to inhibit cyclooxygenase (COX) enzymes and the retinoid X receptor alpha (RXR), on rationally identified potential biomarkers in breast cancer. Patients with resectable breast cancer planned for initial management with surgical resection were enrolled and took 400 mg of etodolac twice daily prior to surgery. Protein and gene expression levels for genes related to COX-2 and RXRα were evaluated in tumor samples from before and after etodolac exposure. Thirty subjects received etodolac and 17 subjects were assayed as contemporaneous or opportunistic controls. After etodolac exposure mean cyclin D1 protein levels, assayed by immunohistochemistry, decreased (P = 0.03). Notably, pre- versus post cyclin D1 gene expression change went from positive to negative with greater duration of etodolac exposure (r = −0.64, P = 0.01). Additionally, etodolac exposure was associated with a significant increase in COX-2 gene expression levels (fold change: 3.25 [95% CI: 1.9, 5.55]) and a trend toward increased β-catenin expression (fold change: 2.03 [95% CI: 0.93, 4.47]). In resectable breast cancer relatively brief exposure to the NSAID etodolac was associated with reduced cyclin D1 protein levels. Effect was also observed on cyclin D1 gene expression with decreasing levels with longer durations of drug exposure. Increased COX-2 gene expression was seen, possibly due to compensatory feedback. These data highlight the utility of even small clinical trials with access to biospecimens for pharmacodynamic studies.

Double-blind, randomised, comparative trial of etodolac SR versus diclofenac in the treatment of osteoarthritis of the knee

A multi-centre, double-blind, randomised parallel-group study was conducted to compare the efficacy and safety between etodolac SR and diclofenac in treating patients with osteoarthritis of the knee. Thirty-two patients receiving etodolac SR (400 mg/day) and 32 patients receiving diclofenac (100 mg/day) were included for analyses. After receiving the study treatment, etodolac SR and diclofenac were shown to produce comparable improvement in pain relief as measured by a 10-cm visual analogue scale. There was no statistically significant difference observed between groups for the degree of functional impairment or the amount of paracetamol taken. The etodolac SR treatment group showed fewer incidents of adverse event. In addition, fewer gastrointestinal symptoms were observed in the etodolac SR treatment group. A statistically higher percentage of etodolac SR-treated patients were better tolerated to the study treatment compared with the diclofenac-treated patients. Etodolac SR-treated patients also took fewer antacids than the diclofenac-treated patients during the treatment period. In conclusion, etodolac SR is an effective treatment with fewer side-effects than diclofenac for patients with osteoarthritis of the knee.