No apparent effect of naproxen on CSF markers of innate immune activation.

We studied 78 participants having a parental or multiple-sibling history of Alzheimer's disease (AD) in a two-year randomized placebo-controlled trial of naproxen 220 mg b.i.d. for mitigation of early AD pathogenesis. Naproxen was detected in cerebrospinal fluid at concentrations ~100 times lower than in plasma, but produced negligible change in immune markers. The repeated lack of benefit in AD prevention trials using naproxen and related drugs may reflect limited CNS permeability, lack of expected drug effects, or both. These findings suggest reconsideration of implications from results of AD prevention trials using anti-inflammatory drugs.