The invention relates to methods, compositions, and uses of those compositions for making medicaments, for potentiating the beneficial effects of inhibitors of COX-1, COX-2, and 5-LOX, and reducing adverse effects, by also administering inhibitors of soluble epoxide hydrolase (“sEH”), with or without also administering one or more cis-epoxyeicosantrienoic acids. The invention further relates to the use of inhibitors of sEH as analgesics and to methods and compositions of epoxides of eicosapentaenoic acid and docosahexaenoic acid, optionally with an inhibitor of sEH, to reduce pain or inflammation or both.