Patienter, der kan være overfølsomme over for celecoxib, et af indholdsstofferne eller sulfonamider (f. eks. antibiotika), bør ikke anvende Onsenal.
Onsenal should not be used in people who may be hypersensitive (allergic) to celecoxib, to any of the other ingredients, or to sulphonamides (such as some antibiotics).