Improve cognitive impairment using mefenamic acid non-steroidal anti-inflammatory therapy: additional beneficial effect found in a controlled clinical trial for prostate cancer therapy.

Inflammation is an essential component of prostate cancer (PCa), and mefenamic acid has been reported to decrease its biochemical progression. The current standard therapy for PCa is androgen deprivation therapy (ADT), which has side effects such as cognitive dysfunction, risk of Alzheimer's disease, and dementia. Published results of in vitro tests and animal models studies have shown that mefenamic acid could be used as a neuroprotector. Objective: Examine the therapeutic potential of mefenamic acid in cognitive impairment used in a controlled clinical trial. Clinical trial phase II was conducted on patients undergoing ADT for PCa. Two groups of 14 patients were included. One was treated with a placebo, while the other received mefenamic acid 500 mg PO every 12hrs for six months. The outcome was evaluated through the Mini-Mental State Examination (MMSE) score at six months. At the beginning of the study, both groups had similar MMSE scores (mefenamic acid vs. placebo: 26.0±2.5 vs. 27.0±2.6, P=0.282). The mefenamic acid group improved its MMSE score after six months compared with the placebo group (27.7±1.8 vs. 25.5±4.2, P=0.037). Treatment with mefenamic acid significantly increases the probability of maintained or raised cognitive function compared to placebo (92% vs. 42.9%, RR=2.2, 95% CI: 1.16-4.03, NNT=2.0, 95% CI: 1.26-4.81, P=0.014). Furthermore, 42.9% of the placebo group patients had relevant cognitive decline (a 2-point decrease in the MMSE score), while in patients treated with mefenamic acid, cognitive impairment was not present. This study is the first conducted on humans that suggests that mefenamic acid protects against cognitive decline.