Opposite effects of the same drug: reversal of topical XXXX by nocebo information.

@entity1 @entity1337 @entity1931 @entity158
UNASSIGNED: Several studies have shown that psychological factors such as learning, expectation, and emotions can affect pharmacological treatment and shape both favorable and adverse effects of drugs. This study investigated whether nocebo information provided during administration of an analgesic cream could reverse topical @entity1337 to @entity1931 . Furthermore, we tested whether nocebo effects were mediated by negative emotional activation. A total of 142 healthy volunteers (73 @entity1 ) were randomized into 6 groups. A topical analgesic cream (Emla) was administered together with suggestions of @entity1337 in 1 group, whereas another group received Emla with suggestions of @entity1931 . Two other groups received a placebo cream together with the same information as the groups receiving Emla. A fifth group received Emla with no specific information about the effect, and the sixth group received no treatment but the same @entity158 induction as the other groups. @entity158 stimulation (48  C) was administered during a pretest and 2 posttests. @entity158 was continuously recorded during stimulation, and measures of subjective stress and blood pressure were obtained before the pretest, after the application of cream, and after the posttests. The results revealed that @entity158 was significantly lower in the group receiving Emla with positive information and highest in the groups receiving suggestions of @entity1931 , regardless of whether Emla or the placebo was administered. Mediation analyses showed that stress and blood pressure mediated @entity1931 after nocebo suggestions. These results suggest that nocebo information can reverse topical @entity1337 and that emotional factors can explain a significant proportion of variance in nocebo @entity1931 .
