Regarding the inadvisability of administering postoperative analgesics in the drinking water of rats (Rattus norvegicus)

The feasibility of administering the pain reliever acetaminophen to rats vi a their water bottles was examined in this study. Two different preparation s of acetaminophen were used, a cherry-flavored suspension and an alcohol-c ontaining solution. Both preparations of acetaminophen were diluted to 6 mg /ml by using normal drinking water. When healthy unmanipulated rats were ex posed to either of the acetaminophen preparations for the first time, the a nimals showed a dramatic reduction in fluid intake. A marked reduction in f ood intake also was associated with the cherry-flavored preparation. These reductions appear to be an expression of the well-characterized neophobic r esponse that can be demonstrated by rodents when they encounter a novel tas te. This neophobic behavior suggests that administering pain relievers to r ats via their drinking water is counterproductive as a means of providing p ain relief.