Previously, we found that guaifenesin enhances analgesia induced by paracetamol. The aim of the present study was to determine whether guaifenesin is able to also increase analgesic activity in the non-steroid anti-inflammatory drugs ibuprofen, nimesulide and celecoxib.
In addition we investigated the influence of guaifenesin on plasma levels of nimesulide. A model of visceral pain consisting of intraperitoneal injection of acetic acid (writhing test) was used.
Levels of nimesulide in plasma were measured by HPLC. All drugs were given orally and tested in mice.